Science of the Total Environment, The (v.416, #)
Review of risk from potential emerging contaminants in UK groundwater
by Marianne Stuart; Dan Lapworth; Emily Crane; Alwyn Hart (pp. 1-21).
This paper provides a review of the types of emerging organic groundwater contaminants (EGCs) which are beginning to be found in the UK. EGCs are compounds being found in groundwater that were previously not detectable or known to be significant and can come from agricultural, urban and rural point sources. EGCs include nanomaterials, pesticides, pharmaceuticals, industrial compounds, personal care products, fragrances, water treatment by-products, flame retardants and surfactants, as well as caffeine and nicotine. Many are relatively small polar molecules which may not be effectively removed by drinking water treatment. Data from the UK Environment Agency's groundwater screening programme for organic pollutants found within the 30 most frequently detected compounds a number of EGCs such as pesticide metabolites, caffeine and DEET. Specific determinands frequently detected include pesticides metabolites, pharmaceuticals including carbamazepine and triclosan, nicotine, food additives and alkyl phosphates. This paper discusses the routes by which these compounds enter groundwater, their toxicity and potential risks to drinking water and the environment. It identifies challenges that need to be met to minimise risk to drinking water and ecosystems.► Emerging groundwater contaminants are derived from agricultural and urban areas and point sources. ► These include pesticide metabolites, pharmaceuticals and personal care products. ► Many are incompletely removed in water treatment. ► There is insufficient information to assess the risk to humans and the environment. ► New compounds need to be identified and their effects defined and quantified.
Keywords: Emerging contaminants; Groundwater; Toxicity; Risk assessment; Pesticides; Pharmaceuticals
The impacts of low-cost treatment options upon scale formation potential in remote communities reliant on hard groundwaters. A case study: Northern Territory, Australia
by Andrew S. Kinsela; Adele M. Jones; Richard N. Collins; T. David Waite (pp. 22-31).
The majority of small, remote communities within the Northern Territory (NT) in Central Australia are reliant on groundwater as their primary supply of domestic, potable water. Saturation indices for a variety of relevant minerals were calculated using available thermodynamic speciation codes on collected groundwater data across the NT. These saturation indices were used to assess the theoretical formation of problematic mineral-scale, which manifests itself by forming stubborn coatings on domestic appliances and fixtures. The results of this research show that 63% of the measured sites within the NT have the potential to form calcium carbonate (CaCO3) scale, increasing to 91% in arid, central regions. The data also suggests that all groundwaters are over-saturated with respect to amorphous calcium-bridged ferric-silica polymers, based on the crystalline mineral index (Ca3Fe2Si3O12), although the quantitative impact of this scale is limited by low iron concentrations. An assessment of possible low-cost/low-technology management options was made, including; lowering the temperature of hot-water systems, diluting groundwater with rainwater and modifying the pH of the source water. Source water pH modification (generally a reduction to pH 7.0) was shown to clearly alleviate potential carbonate-based scale formation, over and above the other two options, albeit at a greater technical and capital expense. Although low-cost/low-technology treatment options are unlikely to remove severe scale-related issues, their place in small, remote communities with minor scale problems should be investigated further, owing to the social, technical and capital barriers involved with installing advanced treatment plants (e.g. reverse osmosis) in such locations.► Scaling potential of small communities reliant on hard groundwaters were analysed. ► Oversaturation of carbonate- and silica-based minerals was widespread. ► Low-cost/-tech treatment options were assessed for treating mineral precipitation. ► Lowering reticulation water temperature and dilution with rainfall proved ineffective. ► Modifying pH (to 7.0) had the greatest impact, albeit at a greater technical cost.
Keywords: Saturation index; Calcium carbonate; Metal silicate; Hard groundwater; Water treatment
A review of the factors causing paralysis in wild birds: Implications for the paralytic syndrome observed in the Baltic Sea
by Christian Sonne; Aage Kristian Olsen Alstrup; Ole Roland Therkildsen (pp. 32-39).
We reviewed paralysis in wild birds with a special focus on the Baltic Sea paralytic syndrome recently described by Balk et al. (2009) by assessing multiple causative factors. The review showed that paralysis may occur in various species and that the aetiology can be divided into biotoxins, nutritional deficiencies, environmental contaminants and infectious diseases. The review also showed that the symptoms are influenced by age, sex and species of the affected individual. It seemed that paralysis may be treated or relieved by e.g. thiamine injections or additives. Due to a lack of extensive diagnostic studies, the potentially negative effects of paralysis at the population level of wild birds remain unsolved. We recommend that when investigating paralysis in wild birds, a holistic study approach including multiple factors are undertaken in order to pinpoint cause-and-effect relationships as well as the potential impacts on wild bird populations including those in the Baltic Sea.► We reviewed the causes of paralysis in wild birds. ► The literature showed that multiple factors may cause avian paralysis. ► These include biotoxins, nutrition, contaminants and infectious diseases. ► Paralysis may be treated or relieved by e.g. thiamine injections or additives. ► We recommend that a holistic study approach is undertaken when investigating paralysis.
Keywords: Botulism; Contaminants; Deficiency; Infectious diseases; Paralysis; Paralytic syndrome
An appraisal of management pathologies in the Great Lakes
by Chris McLaughlin; Gail Krantzberg (pp. 40-47).
Recent research has produced broad application of the health concept to regional ecosystems, including the Great Lakes. The attention is warranted, as new and recurring stresses on the health of the Great Lakes undermine our understanding and hinder our ability to manage and restore critical ecological functions. There is widespread agreement that the Great Lakes are presently exhibiting symptoms of extreme stress and potentially irreversible and catastrophic damage. Historical command and control management has resulted simultaneously in environmental benefits to people and a loss of resilience in Great Lakes ecosystems. Surprising system responses often prompt further control, and the continued decline in resilience has been called the pathology of natural resource management. The pathology is also suggested to affect human systems of organization such as management authorities. We use published criteria of institutional pathologies and illustrate their occurrence in the Great Lakes with evidence of non-existent program evaluation, program incompatibility, lack of coordination among programs, authorities that establish and then abandon public participatory initiatives, and inappropriate choice of policy mechanisms or inadequate level of support for an appropriate mechanism (either of which creates disincentives for stakeholders). Learning is an element of resilience, as managed systems are inherently dynamic and our understanding is therefore always incomplete. Policy mechanisms that mimic learning techniques to improve understanding are therefore central to avoiding pathologies in management. But learning (individually or institutionally) can be threatening and very difficult, and its proper conduct necessarily involves a continuous process of feedback, interpretation, and reformulation. Double-loop learning processes that institutionalize learning in policy are recommended, as these will be required to overcome pathologies in management and maintain resilience of the Great Lakes system.► We examined the pathology of natural resource management with respect to the Great Lakes. ► We applied published criteria of management pathologies to restoration programs. ► We present evidence to illustrate a variety of pathological institutional behaviors. ► Findings relate to limitations in how we conceptualize social‐ecological dynamics. ► Conclusion is that policy mechanisms that mimic learning are central to avoiding pathologies.
Keywords: Great Lakes Water Quality Agreement; Pathology of natural resource management; Institutional culture; Governance reform; Double-loop learning; Ecosystem resilience
Particulate air pollution and cardiorespiratory hospital admissions in a temperate Australian city: A case-crossover analysis
by Alana Hansen; Peng Bi; Monika Nitschke; Dino Pisaniello; Philip Ryan; Thomas Sullivan; Adrian G. Barnett (pp. 48-52).
Although ambient air pollution exposure has been linked with poor health in many parts of the world, no previous study has investigated the effect on morbidity in the city of Adelaide, South Australia.To explore the association between particulate matter (PM) and hospitalisations, including respiratory and cardiovascular admissions in Adelaide, South Australia.For the study period September 2001 to October 2007, daily counts of all-cause, cardiovascular and respiratory hospital admissions were collected, as well as daily air quality data including concentrations of particulates, ozone and nitrogen dioxide. Visibility codes for present weather conditions identified days when airborne dust or smoke was observed. The associations between PM and hospitalisations were estimated using time-stratified case-crossover analyses controlling for covariates including temperature, relative humidity, other pollutants, day of the week and public holidays.Mean PM10 concentrations were higher in the warm season, whereas PM2.5 concentrations were higher in the cool season. Hospital admissions were associated with PM10 in the cool season and with PM2.5 in both seasons. No significant effect of PM on all-age respiratory admissions was detected, however cardiovascular admissions were associated with both PM2.5 and PM10 in the cool season with the highest effects for PM2.5 (4.48%, 95% CI: 0.74%, 8.36% increase per 10μg/m3 increase in PM2.5).These findings suggest that despite the city's relatively low levels of air pollution, PM concentrations are associated with increases in morbidity in Adelaide. Further studies are needed to investigate the sources of PM which may be contributing to the higher cool season effects.► This study investigated air pollution health effects in Adelaide, Australia. ► Days of dust and smoke were identified. ► Particulate matter was associated with hospital admissions. ► Greatest effect was observed in the cool season. ► Fine particles were most strongly associated with cardiovascular admissions.
Keywords: Air pollution; Particulate matter; Cardiovascular disease; Hospital admissions; Morbidity; Case-crossover design
Residential hazards, high asthma prevalence and multimorbidity among children in Saginaw, Michigan
by Jerome Nriagu; Joseph Martin; Pamela Smith; Deborah Socier (pp. 53-61).
Comorbidities complicate our understanding of childhood asthma and its risk factors. This study examined the relationships between asthma, self-reported burden of disease symptoms and residential hazards in a representative sample of households in Saginaw, Michigan.A population-based cross-sectional survey.The study involved 643 households randomly selected from the City of Saginaw (Michigan) with children 12years of age or younger or pregnant woman. The survey was completed using random digit dialing, Computer-Assisted Telephone Interviewing (CATI) method. The audit instrument for residential hazards developed for the study was used to gather information on 71 household hazards organized in eight scales (dimensions): structural scale, moisture/mold scale, electrical scale, ventilation and combustion appliances scale, pest scale, pets scale, fire scale, and lifestyle-associated factors scale. The data were used to calculate an aggregate score of the household hazard index (HHI) for each housing unit. We also collected information on 43 symptoms of diseases likely to be associated with exposure to residential hazards as well as the demographic characteristics for each household.Asthma prevalence rate among the 1206 children was 18.9% with 27.7% of households reporting at least one asthmatic child. The prevalence of health hazards in households of Saginaw was pervasively high with the rate for each of 29 hazards being over 30%. The HHI was found to be a good predictor of health outcomes in homes; the following linear regression equation describes the relationship between childhood asthma and the scores for individual scales of HHI: Number of Asthmatic Children=0.009(Structural)+0.004(Mold) +0 .019(Pests)–0.023(Pets)–0.029(Fire); (r2=0.054; p-value<0.001). Children who were living in housing units classified as high risk (top 25% of the HHI score) were found to be disproportionately afflicted with asthma, allergic reaction and burden of symptoms compared to children who lived in low-risk homes. Average number of symptoms in the households was 14±10 and the top 25% of the households had over 26 symptoms. Asthma was associated (comorbid) with each of the 40 symptoms (out of the 43) in the inventory scale, and the HHI was found to be a good predictor of the symptom burden (total count of symptoms) in participating households.Recognition of the large extent of comorbidity in asthmatic children has implications for the way in which this disease should be treated or managed. In addition, the study of comorbidity between asthma and related risk factors may be important in understanding complex exposure-disease relationships which could lead to more effective interventions.► We developed a parsimonious measure of hazards that can be associated with housing-related diseases. ► We conducted a population-based cross-sectional that involved 643 households randomly selected from the City of Saginaw (Michigan). ► Asthma prevalence rate among the 1206 children was found to be 19% with 28% of households had at least one asthmatic child. ► Average number of symptoms in the households was 14 and the top 25% of the households had over 26 disease symptoms. ► The recommend the use of the new scale with existing health database for exploring the intersection of housing and health issues in a more rigorous manner.
Keywords: Childhood asthma; Comorbidity; Multimorbidity; Disease burden; Residential hazards; Household hazard index
Levels of DDT and its metabolites in placenta, maternal and cord blood and their potential influence on neonatal anthropometric measures
by Iman Al-Saleh; Inaam Al-Doush; Ammar Alsabbaheen; Gamal El Din Mohamed; Abdullah Rabbah (pp. 62-74).
Previous studies of in utero exposure to dichlorodiphenyltrichloroethane (DDT) have shown mixed results for the harmful effects on fetal growth and development. This cross-sectional study was designed to: (1) examine the extent of DDT exposure in 1578 women, aged 28.5±6.0 who delivered between June 2005 and 2006 in the area of Al-Kharj, Saudi Arabia; and (2) assess its influence on neonatal anthropometric measurement of newly born babies. DDT and its metabolites, namely 1,1-dichloro-2,2-bis ( p-chlorophenyl) ethylene ( p, p′-DDE), 1,1-dichloro-2,2-bis ( p-chlorophenyl) ethane ( p, p′-DDD) and 1,1,1-trichloro-2,2′ bis ( p-chlorophenyl) ethane ( p, p′-DDT) were measured in cord and maternal serum as well as placenta by Gas Chromatography coupled with an Electron Capture Detector (GC/ECD). p,p′-DDE was detected in 28.3% of cord and 54.4% of maternal serum, reflecting past exposure, whereas the p,p′-DDT was only found in 0.46% cord and 1.2% maternal samples. As expected the p,p′-DDE cord levels (0.197±0.961μg/L) were 2.8 times lower than the maternal levels (0.551±1.778μg/L), and both were significantly correlated ( r=0.517) suggesting its transplacental transfer. The picture was different in placental tissues. p,p′-DDE and p,p′-DDT were detected in 84% and 99% of placental tissues, with the highest p,p′-DDT in placental tissues (29.62±158.282µg/kg dry wt.) compare to p,p′-DDE (10.167±18.851μg/kg dry wt.). In general, the presence of DDT metabolites in our participants indicates that these chemicals are still relevant despite the fact that they have been banned or restricted in the study area for many years. Our results support the view for an association between low in utero exposure to DDT and the anthropometric development of the fetus leading to a reduction in its head circumference, crown–heel length, birth weight and birth height. Since the reduction in these measures was independent of gestational age and/or preterm births, our findings suggest a detrimental effect of the DDT exposure on fetal growth. Neonatal anthropometric measures are considered as an important tool to detect newborns at higher risk of morbidity and impairment of growth. Efforts should be made to decrease exposure of women of reproductive age and to examine maternal DDT exposure in relation to long-term impact on health.► We examined the extent of DDT exposure and assess its influence on neonatal anthropometric measurements. ► Maternal and placental p,p′-DDE were found respectively in 54% and 84% of the women. ► The presence of DDT metabolites suggests that these chemicals are still found in spite of banning its use. ► An influence of maternal DDT levels on head circumference, crown–heel length, birth weight and birth height was found. ► Further studies are needed to examine maternal DDT exposure in relation to long-term health impact.
Keywords: p,p′-; DDE; p,p′-; DDT, maternal serum; Cord serum; Placenta; Neonatal anthropometric measures; Small for gestation age
Long term use of triclosan toothpaste and thyroid function
by Mary P. Cullinan; Janet E. Palmer; Anne D. Carle; Malcolm J. West; Gregory J. Seymour (pp. 75-79).
The long term effects of usage of triclosan-containing toothpaste on thyroid function are currently unknown. Triclosan is structurally similar to thyroid hormones and reductions in serum thyroid hormone levels have been observed in animal studies following oral administration of triclosan. Therefore, an assessment of thyroid function over 4years was undertaken in a subset of individuals in a randomised, placebo controlled clinical trial comparing the effects of 0.3% triclosan toothpaste with placebo toothpaste in subjects with coronary heart disease. Thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), antithyroglobulin antibody (anti-TGab) and antithyroid peroxidase antibody (TPOab) were measured.Paired serum samples at year 1 and year 5 from 132 subjects (64 triclosan group, 68 placebo group) were analysed. At year 1 there were no significant differences in thyroid function between the groups: mean (SD) TSH 1.4 (0.8) and 1.6 (0.9) mU/L, triclosan and placebo groups respectively, fT4 15.8 (2.2) and 15.2 (2.1) pmol/L; fT3 4.8 (0.5) and 4.8 (0.5) pmol/L. Similarly, for antithyroid antibodies there were no group differences at year 1. Median (25th, 75th percentile) for anti-TGab, 38 (34, 42) and 37 (30, 42) U/mL triclosan and placebo groups respectively; anti-TPOab, 15 (10, 22) and 18 (10, 24) U/mL. At year 5, fT4 was the only measure to show a significant difference between groups (mean and 95% Confidence Interval) 15.6 (15.1, 16.1) and 14.7 (14.2, 15.1) pmol/L triclosan and placebo respectively (p=0.01). This reflects reduced levels in the placebo group but no change in the triclosan group.In conclusion, over 4years triclosan toothpaste had no detectable effect on thyroid function. The data support the view that 0.3% triclosan in toothpaste is safe and free of significant thyroid adverse effects.► Triclosan is widely used in consumer products. ► It is found in human plasma, urine and breast milk. ► The first long term study to examine its effect on thyroid function in humans. ► We examine changes in thyroid function after long-term use of triclosan toothpaste. ► After 4years triclosan toothpaste had no detectable effect on thyroid function.
Keywords: Triclosan; Toothpaste; Thyroid function; Endocrine; Human; RCT
Circulating levels of metals are related to carotid atherosclerosis in elderly
by P. Monica Lind; Olsen Lena Olsén; Lars Lind (pp. 80-88).
The aim of this study was to investigate if blood levels of trace and/or heavy metals are related to atherosclerosis in a cross-sectional study in elderly.In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects, all aged 70), the prevalence of carotid artery plaques was recorded by ultrasound. The numbers of carotid arteries with plaques (0, 1 or 2) were recorded. Also the thickness (IMT) and gray scale (IM-GSM) of the intima-media complex were measured together with plaque echogenicity. Eleven heavy metals and trace elements were analyzed in whole blood, using inductively coupled plasma-sector field mass spectrometry.Nickel levels were related to the number of carotid arteries with plaques in an inverted U-shaped manner after multiple adjustment for gender, waist circumference, body mass index, fasting blood glucose, systolic and diastolic blood pressure, HDL and LDL cholesterol, serum triglycerides, smoking, antihypertensive treatment and statin use (p=0.026). IM-GSM and plaque echogenicity were both inversely related to chromium in a linear fashion, and to aluminum in an inverted U-shaped manner (both p<0.0001 for IM-GSM). The relationships between metals and IMT were modest.Circulating levels of some metals, like nickel, aluminum and chromium, were related to atherosclerotic plaques or the echogenicity of the IM-GSM and overt plaques independently of cardiovascular risk factors, including lipids.►We examine correlation between levels of 11 metals and atherosclerosis in elderly. ►A cross-sectional study with 1016 subjects aged 70. ►Carotid artery plaques were recorded by ultrasound. ►Nickel, aluminum and chromium were related to atherosclerotic plaques.
Keywords: Abbreviations; Al; aluminum; BMI; body mass index; Cd; cadmium; Co; cobalt; Cu; copper; Cr; chromium; CV; cardiovascular; DBP; diastolic blood pressure; HDL; high-density lipoprotein; Hg; mercury; ICP-SFMS; inductively coupled plasma-sector field mass spectrometry; IM-GSM; intima-media complex; IMT; intima-media thickness; LDL; low-density lipoprotein; Mn; manganese; Mo; molybdenum; Ni; nickel; Pb; lead; PIVUS; Prospective Investigation of the Vasculature in Uppsala Seniors; SBP; systolic blood pressure; Zn; zincAtherosclerosis; Metals; Atherosclerotic plaques; Trace elements; Elderly
Noise frequency components and the prevalence of hypertension in workers
by Ta-Yuan Chang; Chiu-Shong Liu; Li-Hao Young; Ven-Shing Wang; Shen-En Jian; Bo-Ying Bao (pp. 89-96).
Epidemiological studies have demonstrated a relationship between noise exposure and hypertension, but the association between hypertension and noise frequency components remains unclear. This cross-sectional study investigated the association between noise exposure at different frequencies and the prevalence of hypertension in 188 screw-manufacturing workers. Participants were divided into one high-noise-exposure group (≥80 A-weighted decibel, [dBA]; n=68) and two reference groups, including 68 low-noise-exposure workers (75.8±3.2 dBA) and 52 office workers (61.5±0.5dBA). Personal noise exposure and environmental octave-band analyses were performed at work. Multiple logistic regression models were used to estimate odds ratios (ORs) for hypertension between different noise-exposure categories after adjustment for potential confounders. Male workers exposed to noise levels at high frequencies of 2000, 4000 or 8000Hz had a higher but non-significant risk of hypertension. Those exposed to ≥80dBA for 2–4years, 4–6years and more than 6years had a 4.43-fold (95% CI=1.21–16.15), 1.21-fold (95% CI=0.35–4.21) and 0.95-fold (95% CI=0.16–5.60) risk of hypertension, respectively, compared with reference workers. A significant association was only observed in male workers exposed to ≥70dBA at 4000Hz for 2–4years (adjusted OR=4.22; 95% CI=1.15–15.49) and was not found at other frequencies for any periods. These findings suggest that occupational noise exposure above 80dBA for specific periods may be associated with hypertension, and noise frequency at 4000Hz may have the greatest effect on hypertension.► Associations between noise frequency characteristics and hypertension are unclear. ► Male workers exposed to≥80 dBA for 2–4years have a higher risk of hypertension. ► Only noise levels≥70 dBA at 4000Hz for 2–4years is associated with hypertension. ► Adverse effects of noise frequency components on hypertension should be considered.
Keywords: Abbreviations; BMI; body mass index; 95% CI; 95% confidence interval; dBA; A-weighted decibel; DBP; diastolic blood pressure; HPD; hearing protective device; LA; eq; A-weighted equivalent sound level; OR; odds ratio; SBP; systolic blood pressureCross-sectional study; Frequency analysis; Hypertension; Occupational noise; Workers
Associating emergency room visits with first and prolonged extreme temperature event in Taiwan: A population-based cohort study
by Yu-Chun Wang; Yu-Kai Lin; Chun-Yu Chuang; Ming-Hsu Li; Chang-Hung Chou; Chun-Hui Liao; Fung-Chang Sung (pp. 97-104).
The present study evaluated emergency room visit (ERV) risks for all causes and cardiopulmonary diseases associated with temperature and long-lasting extreme temperatures from 2000 to 2009 in four major cities in Taiwan. The city-specific daily average temperatures at the high 95th, 97th, and 99th percentiles, and the low 10th, 5th, and 1st percentiles were defined as extreme heat and cold. A distributed lag non-linear model was used to estimate the cumulative relative risk (RR) of ERV for morbidities associated with temperatures (0 to 3-day lags), extreme heat and cold lasting for 2 to 9days or longer, and with the annual first extreme heat or cold event after controlling for covariates. Low temperatures were associated with slightly higher ERV risks than high temperatures for circulatory diseases. After accounting for 4-day cumulative temperature effect, the ERV risks for all causes and respiratory diseases were found to be associated with extreme cold at the 5th percentile lasting for >8days and 1st percentile lasting for >3days. The annual first extreme cold event of 5th percentile or lower temperatures was also significantly associated with ERV, with RRs ranging from 1.09 to 1.12 for all causes and from 1.15 to 1.26 for respiratory diseases. The annual first extreme heat event of 99th percentile temperature was associated with higher ERV for all causes and circulatory diseases. Annual first extreme temperature event and intensified prolonged extreme cold events are associated with increased ERVs in Taiwan.►Prolonged intensified cold extremes cause significant risks on ERV. ►Annual first extreme heat or cold event significantly elevates the ERV. ►Extreme temperature events cause greater adverse effects than temperature on ERV.
Keywords: Abbreviations; CI; confidence interval; CWB; Central Weather Bureau; DLNM; distributed lag non-linear model; ERV; emergency room visit; Flu; influenza; NHRI; National Health Research Institute; PM; 10; particulate matter less than 10; μm in aerodynamic diameter; RR; relative risk; RH; relative humidity; TCDC; Taiwan Centers for Disease Control; TEPA; Taiwan Environmental Protection Administration; WS; wind speedEmergency room visits; Circulatory; Respiratory; Extreme temperature event; Taiwan
Decreased birth weight in relation to maternal urinary trichloroacetic acid levels
by Wen-Shan Zhou; Liang Xu; Shao-Hua Xie; Ya-Lin Li; Li Li; Qiang Zeng; Yu-Kai Du; Wen-Qing Lu (pp. 105-110).
The effect of exposure to disinfection by-products (DBPs) during pregnancy on newborn's birth weight has been commonly described in animal studies. However, epidemiological evidence was not consistent.To investigate the relationship between exposure to DBPs and newborn's birth weight in a Chinese population, we conducted a cross-sectional study in Wuhan, China.A total number of 398 women who had given birth to a live singleton with a gestational age between 37 to 42weeks were recruited from a local hospital between November 2008 and May 2009. Basic information for all mothers and newborns was obtained from clinic birth records. Among these subjects, 180 women also gave further information including maternal medical history, social status and water-use behaviors by a face-to-face interview. Urinary creatinine (Cr) adjusted trichloroacetic (TCAA) was used as an exposure biomarker.No statically significant results were found in the linear regression for both 398 participants and 180 participants who finished questionnaires. However, both the crude and adjusted results showed that the mean birth weight of the subjects in the third and top quartiles of Cr-adjusted urinary TCAA concentrations was decreased compared with those in the lowest quartile. Subjects in the top quartiles had the lowest mean birth weight compared to those in other quartiles. In addition, a weak correlation was observed among 82 subjects between drinking water ingestion and urinary Cr-adjusted TCAA (r=0.23, P=0.04).Our findings suggested that elevated exposure to DBPs may affect fetal growth. The effect of exposure to DBPs during pregnancy on birth weight still warrants further investigations.► Urinary Cr adjusted TCAA was used as an exposure biomarker for DBPs exposure. ► Elevated exposure to DBPs may affect fetal growth. ► Urinary TCAA levels could be a good biomarker in epidemiological studies on health effects of DBPs.
Keywords: Abbreviations; DBPs; produce disinfection by-products; Cr; creatinine; THMs; trihalomethanes; HAAs; haloacetic acid; DCAA; dichloroacetic acid; TCAA; trichloroacetic acid; HANs; haloacetonitriles; DCAN; dichloroacetonitrile; TCANs; trichloroacetonitrile; LBW; low birth weight; IUGR; intrauterine growth retardation; FMU; first morning urinary; LOD; limit of detection; BMI; body mass index; TTHMs; total THMs; TCE; trichloroethylene; TRI; 1,1,1-trichloroethane; PERC; perchloroethyleneDisinfection by-products; Birth weight; Trichloroacetic acid; Exposure biomarker; Reproductive health
Expanding perceptions of subsistence fish consumption: Evidence of high commercial fish consumption and dietary mercury exposure in an urban coastal community
by Erica L. Holloman; Michael C. Newman (pp. 111-120).
Through collaborative partnerships established between current researchers and The Moton Community House (a local community center), African American women (ages 16–49yrs) from the Southeast Community of Newport News, Virginia, USA were surveyed to assess the reproducibility and consistency of fish consumption patterns (ingestion rates, exposure frequencies, weight, and fish consumption rates) derived from a community-specific fish consumption survey. Women were also surveyed to assess the reliability of the survey responses, and to estimate daily mercury intake. Fish consumption patterns were reproducible and the survey responses were reliable. Comparison between years revealed that fish consumption patterns remained consistent over time. In addition, the high fish consumption rate estimated in 2008 (147.8g/day; 95% CI: 117.6–185.8g/day) was confirmed with a rate (134.9g/day; 95% CI: 88–207g/day) not materially different and still considerably higher than mean fish consumption rates reported for U.S. women. Daily mercury intake rates were estimated using consumption data from 2008 and three consumption scenarios (canned white, canned light, and no tuna) due to confirmed differences in mercury concentration between canned white and light tuna. Arithmetic mean daily mercury intake rates were 0.284μg/kg bw/day (95% CI: 0.229–0.340μg/kg bw/day) using canned white tuna, 0.212μg/kg bw/day (95% CI: 0.165–0.259μg/kg bw/day) using light tuna, and 0.197μg/kg bw/day (95% CI: 0.151–0.243μg/kg bw/day) using no tuna. Approximately 58%–73% of the daily mercury intake rates for African American women in the Southeast Community exceeded US EPA's oral reference dose (RfD) of 0.10μg/kg bw/day for mercury. In addition, 2% of the rates exceeded a level (1.00μg/kg bw/day) documented to produce adverse health effects. Past and current investigations confirmed that even though women in this community were not subsistence fishers, they are subsistence fish consumers.► Fish consumption rates were the highest reported for African American women. ► Fish items consumed were mainly from commercial sources. ► African American women in this community are subsistence fish consumers. ► 58–73% of the mercury intake rates would exceed US EPA's oral reference dose. ► 2% of the rates would exceed a dose documented to produce adverse health effects.
Keywords: Subsistence; Fish consumption; Mercury exposure; African American women
Occupational safety and health practices among flower greenhouses workers from Alto Tietê region (Brazil)
by Marcela G. Ribeiro; Camilla G. Colasso; Paula P. Monteiro; Walter R. Pedreira Filho; Maurício Yonamine (pp. 121-126).
In this preliminary study the occupational safety and health practices among flower greenhouses workers were evaluated. The study was carried out in the alto Tietê region, located at the Sao Paulo State, Brazil. Inadequate welfare facilities; poor pesticide storage, use and disposal conditions; use of highly toxic pesticides; lack of adequate data regarding pesticide use; and incorrect use and maintenance of PPE were observed in most of the visited greenhouses. These results suggest that, in greenhouses, workers may be at higher risk of pesticide exposure, due to many factors that can intensify the exposure such as the lack of control on reentry intervals after pesticide application. Specific regulations are needed to ensure better OSH practices on pesticide use and to improve working conditions in greenhouses, in order to deal with the peculiarities of greenhouse working environment. Some of the special requirements for greenhouses workers' protection are the establishment of ventilation criteria for restricted entry interval; clear reentry restrictions; and EPI for workers other than applicators that need to enter the greenhouse before expiring REI interval. Another important way to improve OSH practices among workers includes the distribution of simple guidelines on the dos and don'ts regarding OSH practices in greenhouses and extensively training interventions to change the perception of hazards and the behavior towards risk.► Occupational safety and health practices among flower greenhouses workers were evaluated. ► Lack of clear reentry restrictions can intensify the exposure in greenhouses. ► Specific regulations dealing with the peculiarities of greenhouse working environment are needed. ► Distribution of simple guidelines relying on greenhouse working can improve OSH practices. ► Training interventions are important to change the workers' perception of hazards and behavior towards risk.
Keywords: Greenhouses; OSH practices; Pesticides; Occupational exposure
Diffusive gradients in thin films (DGT) for the prediction of bioavailability of heavy metals in contaminated soils to earthworm ( Eisenia foetida) and oral bioavailable concentrations
by Rabindra Bade; Sanghwa Oh; Won Sik Shin (pp. 127-136).
The applicability of diffusive gradients in thin-films (DGT) as a biomimic surrogate was investigated to determine the bioavailable heavy metal concentrations to earthworm ( Eisenia foetida). The relationships between the amount of DGT and earthworm uptake; DGT uptake and the bioavailable concentrations of heavy metals in soils were evaluated. The one-compartment model for the dynamic uptake of heavy metals in the soil fitted well to both the earthworm (R2=0.641–0.990) and DGT (R2=0.473–0.998) uptake data. DGT uptake was linearly correlated with the total heavy metal concentrations in the soil ( aqua regia), the bioavailable heavy metal concentrations estimated by fractions I+II of the standard measurements and testing (SM&T) and physiologically based extraction test (PBET, stomach+intestine). The coefficients of determination (R2) of DGT uptake vs. aqua regia were 0.433, 0.929 and 0.723; vs. SM&T fractions (I+II) were 0.901, 0.882 and 0.713 and vs. PBET (stomach+intestine) were 0.913, 0.850 and 0.649 for Pb, Zn and Cu, respectively. These results imply that DGT can be used as a biomimic surrogate for the earthworm uptake of heavy metals in contaminated soils as well as predict bioavailable concentrations of heavy metals estimated by SM&T (I+II) and PBET as a human oral bioavailable concentrations of heavy metals.► Diffusive gradients in thin-films (DGT) can estimate bioavailable heavy metal concentrations in contaminated soils. ► Earthworm uptake can reflect the bioavailability of heavy metals in the soils. ► SM&T (I+II) and PBET (stomach+intestine) also reflect the bioavailability of heavy metals in the soils. ► Good relationship between DGT and earthworm uptakes is estimated by one-compartment model analysis. ► DGT can be used as a biomimic surrogate for the earthworm uptake of heavy metals in the soils.
Keywords: Bioavailable concentration; Diffusive gradients in thin films (DGT); Earthworm; Heavy metals; One-compartment model; Soil
First evidences of the occurrence of polycyclic synthetic musk fragrances in surface water systems in Italy: Spatial and temporal trends in the Molgora River (Lombardia Region, Northern Italy)
by Sara Villa; Laura Assi; Alessio Ippolito; Patrizia Bonfanti; Antonio Finizio (pp. 137-141).
The polycyclic synthetic musks (PCMs) such as galaxolide (HHCB), tonalide (AHTN) and celestolide (ABDI) are important ingredients in fragrances for consumer products because of their typical musky scent. In EU, PCMs are classified as HPVC (High Production Volume Chemicals). Furthermore, it has been recognized that these substances are only partially degraded in domestic sewers. For both reasons these chemicals are considered ubiquitous contaminants of aquatic systems. Monitoring data are available for the Northern region of the EU, but it is not known whether they are also representative for the Southern EU countries. The lack of data upon the environmental exposure in Southern EU can be significant, since use patterns and volumes differ from country to country. This is particularly true for Italy that has the largest detergent consumption per capita in EU. Due to this, the objective of the present study was to investigate the occurrence of selected PCMs in the Molgora River (Lombardia region, Italy). To our knowledge it represents the first overview of PCM occurrence in the Italian water bodies. Water samples were collected seasonally in seven sampling stations located before and after the 3 sewage treatment plants present along the river, which serve about 300,000 inhabitants. The spatial and temporal profiles of contamination are described. A comparison of the results with existing monitoring data of other European regions indicated a significant higher level of PCM pollution of the Molgora River and the need to extend the monitoring campaigns to other Italian water bodies, in order to achieve a better knowledge of the levels of PCM contamination in this country.► We monitored the presence of polycyclic synthetic musk fragrances in an Italian river. ► Spatial and temporal profiles of contamination up and downstream 3 STPs are described. ► These are the first data reporting the presence of PCPs in Italian rivers.
Keywords: Musk fragrances; Galaxolide; Tonalide; Celestolide; Molgora River; Wastewater treatment plant
Experimental assessment of level pool routing in preliminary design of floodplain storage
by Giuseppe De Martino; Francesco De Paola; Nicola Fontana; Gustavo Marini; Antonio Ranucci (pp. 142-147).
Among control structures in flood management, floodplain storage represents one of the most effective measures, since it holds part of flood volume in a delimited area thus reducing the peak discharge. Sizing of floodplain storage, both on-stream and off-stream, is complex and several methodologies for preliminary design are available in literature, almost all assuming level pool reservoir routing, i.e. the water level in the floodplain is horizontal during the storage filling. Few studies examine the accuracy of that assumption. The present paper work reports an extensive experimental investigation to assess the reliability of level pool routing in the design of on-stream floodplain storages. The good agreement between numerical and experimental values during the filling phase confirmed the reliability of the hypothesis in the preliminary sizing of on-stream floodplain storage. In contrast, even significant differences can be shown during the floodplain draining, due to vegetation and bottom irregularities.► Extensive experimental investigation to assess the reliability of level pool routing ► Experiments were carried out on laboratory installation ► Preliminary design of on-stream floodplain storages ► Numerical model — experimental data comparison
Keywords: Flood mitigation; Flood control; Floodplain; Laboratory tests
Impacts of pesticides and natural stressors on leaf litter decomposition in agricultural streams
by Jes Jesssen Rasmussen; Peter Wiberg-Larsen; Annette Baattrup-Pedersen; Rikke Juul Monberg; Brian Kronvang (pp. 148-155).
Agricultural pesticides are known to significantly impact the composition of communities in stream ecosystems. Moreover, agricultural streams are often characterised by loss of physical habitat diversity which may impose additional stress resulting from suboptimal environmental conditions. We surveyed pesticide contamination and rates of leaf litter decomposition in 14 1st and 2nd order Danish streams using litter bags with coarse and fine mesh sizes. Two sites differing in physical habitat complexity were sampled in each stream, and we used this approach to differentiate the effects of pesticides between sites with uniform (silt and sand) and more heterogeneous physical properties.Microbial litter decomposition was reduced by a factor two to four in agricultural streams compared to forested streams, and we found that the rate of microbial litter decomposition responded most strongly to pesticide toxicity for microorganisms and not to eutrophication. Moreover, the rate of microbial litter decomposition was generally 50% lower at sites with uniform physical habitats dominated by soft substrate compared to the sites with more heterogeneous physical habitats. The rate of macroinvertebrate shredding activity was governed by the density of shredders, and the density of shredders was not correlated to pesticide contamination mainly due to high abundances of the amphipod Gammarus pulex at all sites. Our study provides the first field based results on the importance of multiple stressors and their potential to increase the effect of agricultural pesticides on important ecosystem processes.► Microbial litter decomposition is impacted by agricultural pesticide contamination. ► Pesticide impacts on microorganism over-rule stimulating effects of eutrophication. ► Pesticide effects are increased at sites with physically degraded habitats. ► Shredder decomposition is primarily correlated to shredder density. ► This study has strong implications for future stream management and risk assessment.
Keywords: Macroinvertebrates; Microorganisms; Pesticide contamination; Leaf litter decomposition; Streams; Multiple stressors
Transfer of U, Al and Mn in the water–soil–plant ( Solanum tuberosum L.) system near a former uranium mining area (Cunha Baixa, Portugal) and implications to human health
by M.O. Neves; V.R. Figueiredo; M.M. Abreu (pp. 156-163).
Knowledge about metals in crops, grown in contaminated soils around mine sites, is limited and concerns about exposure to hazardous elements through the consumption of contaminated foodstuff, are high. In this study a field experiment was carried out in two agricultural soils located near a former uranium mine area (Cunha Baixa, Portugal). The purpose of the study was to assess the effect of irrigation water quality on soil–potato ( Solanum tuberosum L.) crop system and to evaluate if the consumption of the crop represents health risk to the local villagers. The soils were divided in two plots: one irrigated with contaminated water (U: 1.03–1.04mg/L; Al: 7.5–8.00mg/L; Mn: 4.52mg/L) and the other with uncontaminated water (U: 14–10μg/L; Al: 17–23μg/L; Mn: 2.4–5.7μg/L). After irrigation and potato growth, only soil characteristics, as salinity and total U and Mn concentrations were significantly different from those measured at the beginning of the experiment. Within the potato plants, elements were mostly translocated and concentrated in the aerial part: stems and leaves (U: 73–87%; Al: 85–96%; Mn: 85–94%), which minimize the risk of contamination of the edible tissue. In potato tubers, the highest average concentrations (121–590μg U/kg; 25–64mg Al/kg; 12–13mg Mn/kg dry weight) were registered at soil plots irrigated with contaminated water. Uranium and Al were mostly concentrated in the potato peel (88–96 and 76–85%, respectively), and Mn (67–78%) in the pulp, which reinforces the importance of removing peel to minimize human exposure. The risk analysis calculated for non-cancer health effects (hazard quotient), related only to the exposure through the consumption of this basic foodstuff, revealed safety for Cunha Baixa village residents (adults and children) even when potato crop was grown on U enriched soils and irrigated with contaminated water.► Field experiment with potato in agricultural soils near a former uranium mine site ► U, Al and Mn transfer from water irrigation to soil, potato and man ► Contaminated irrigation water did not change significantly soil characteristics ► High element accumulation in aerial tissues and tuber peel minimizes human exposure ► Potatoes from U enriched soils irrigated with contaminated water are safe for humans
Keywords: Uranium contamination; Water–soil–plant interaction; Solanum tuberosum; L.; Health risk; Cunha Baixa (Portugal)
Assessing dietary exposure to cadmium in a metal recycling community in Vietnam: Age and gender aspects
by Ngo Duc Minh; Rupert Lloyd Hough; Le Thi Thuy; Ylva Nyberg; Le Bach Mai; Nguyen Cong Vinh; Nguyen Manh Khai; Oborn Ingrid Öborn (pp. 164-171).
This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n=132) in Vietnam in comparison to an agricultural (reference) community (n=130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published ‘safe’ doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18–60years) in the recycling village compared to the reference village (p<0.001). Rice was the main staple food with individuals consuming 461±162g/d, followed by water spinach (103±51kg/d). Concentrations of Cd in the studied foodstuffs were elevated in the metal recycling village. Values of HQ exceeded unity for 87% of adult participants of the metal recycling community (39% had a HQ>3), while 20% of adult participants from the reference village had an HQ>1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight.► First individual-level risk assessment of cadmium in recycling villages of Vietnam. ► Dietary analysis undertaken for a recycling community and an agricultural community. ► No significant differences were found between the diets of the two populations. ► 87% of people in the recycling community had elevated health risk. ► WHO standard (0.4mg Cd/kg rice) may not be protective for rice-based cultures.
Keywords: Heavy metals; Rice; Food chain contamination; Risk; Exposure
An impact assessment methodology for urban surface runoff quality following best practice treatment
by J. Bryan Ellis; D. Michael Revitt; Lian Lundy (pp. 172-179).
The paper develops an easy to apply desk-based semi-quantitative approach for the assessment of residual receiving water quality risks associated with urban surface runoff following its conveyance through best practice sustainable drainage systems (SUDS). The innovative procedure utilises an integrated geographical information system (GIS)-based pollution index approach based on surface area impermeability, runoff concentrations/loadings and individual SUDS treatment performance potential to evaluate the level of risk mitigation achievable by SUDS drainage infrastructure. The residual impact is assessed through comparison of the determined pollution index with regulatory receiving water quality standards and objectives. The methodology provides an original theoretically based procedure which complements the current acute risk assessment approaches being widely applied within pluvial flood risk management.► An easy to use desk-based semi-quantitative approach for assessing residual receiving water quality risks is proposed. ► The impacts of urban surface runoff after treatment within sustainable drainage systems are assessed. ► Source pollutant contributions mitigated by removal efficiencies are compared with receiving water quality standards. ► The procedure is illustrated using an urban regeneration area and a hypothetical section of motorway. ► Stormwater managers and regulators are provided with a tool for planning future urban runoff treatment strategies.
Keywords: Impact assessment; Water pollution mitigation; Sustainable drainage systems (SUDS)
Risk assessment of potentially toxic elements in agricultural soils and maize tissues from selected districts in Tanzania
by Ernest M.M. Marwa; Andrew A. Meharg; Clive M. Rice (pp. 180-186).
A field survey was conducted to investigate the contamination of potentially toxic elements (PTEs) arsenic (As), lead (Pb), chromium (Cr), and nickel (Ni) in Tanzanian agricultural soils and to evaluate their uptake and translocation in maize as proxy to the safety of maize used for human and animal consumption. Soils and maize tissues were sampled from 40 farms in Tanzania and analyzed using inductively coupled plasma-mass spectrometry in the United Kingdom. The results showed high levels of PTEs in both soils and maize tissues above the recommended limits. Nickel levels of up to 34.4 and 56.9mgkg−1 respectively were found in some maize shoots and grains from several districts. Also, high Pb levels >0.2mgkg−1 were found in some grains. The grains and shoots with high levels of Ni and Pb are unfit for human and animal consumption. Concentrations of individual elements in maize tissues and soils did not correlate and showed differences in uptake and translocation. However, Ni showed a more efficient transfer from soils to shoots than As, Pb and Cr. Transfer of Cr and Ni from shoots to grains was higher than other elements, implying that whatever amount is assimilated in maize shoots is efficiently mobilized and transferred to grains. Thus, the study recommended to the public to stop consuming and feeding their animals maize with high levels of PTEs for their safety.► High Ni and Pb levels above the allowable limits were found in maize grains. ► Also maize shoots unfit for animal use were found with high Ni concentrations. ► Mining activities were among the sources of soil contamination. ► The public advised to stop consuming maize with potentially toxic elements.
Keywords: Maize; Potentially toxic elements; Soil; Tanzania
Risk–benefit evaluation of fish from Chinese markets: Nutrients and contaminants in 24 fish species from five big cities and related assessment for human health
by Zhen-Yu Du; Jian Zhang; Chunrong Wang; Lixiang Li; Qingqing Man; Anne-Katrine Lundebye; Froyland Livar Frøyland (pp. 187-199).
The risks and benefits of fish from markets in Chinese cities have not previously been fully evaluated. In the present study, 24 common fish species with more than 400 individual samples were collected from markets from five big Chinese cities in 2007. The main nutrients and contaminants were measured and the risk–benefit was evaluated based on recommended nutrient intakes and risk level criteria set by relevant authorities. The comprehensive effects of nutrients and contaminants in marine oily fish were also evaluated using the data of two related human dietary intervention trials performed in dyslipidemic Chinese men and women in 2008 and 2010, respectively. The results showed that concentrations of contaminants analyzed including DDT, PCB7, arsenic and cadmium were much lower than their corresponding maximum limits with the exception of the mercury concentration in common carp. Concentrations of POPs and n-3 LCPUFA, mainly EPA and DHA, were positively associated with the lipid content of the fish. With a daily intake of 80–100g marine oily fish, the persistent organic pollutants in fish would not counteract the beneficial effects of n-3 LCPUFA in reducing cardiovascular disease (CVD) risk markers. Marine oily fish provided more effective protection against CVD than lean fish, particularly for the dyslipidemic populations. The risk–benefit assessment based on the present daily aquatic product intake in Chinese urban residents (44.9 and 62.3g for the average values for all cities and big cities, respectively) indicated that fish, particularly marine oily fish, can be regularly consumed to achieve optimal nutritional benefits from n-3 LCPUFA, without causing significant contaminant-related health risks. However, the potential health threat from contaminants in fish should still be emphasized for the populations consuming large quantities of fish, particularly wild fish.► We collected 24 fish species with more than 400 individual samples from five big Chinese cities. ► The health risk–benefit was evaluated based on the nutrients and contaminants content in fish. ► Two human trials were performed to evaluate the effects of contaminated fish on CVD prevalence. ► Contaminants in these fish couldn't alleviate the benefits of fish n-3 LCPUFA in CVD prevention. ► These fish in China can be regularly consumed without causing contaminant-related health risks.
Keywords: Abbreviations; AHA; American Heart Association; DDT; dichlorodiphenyltrichloroethane; DHA; docosahexaenoic acid; CVD; cardiovascular disease; EFSA; European Food Safety Authority; EPA; eicosapentaenoic acid; FDA; Food and Drug Administration; JECFA; Joint FAO/WHO Expert Committee on Food Additives; LCPUFA; long chain polyunsaturated fatty acid; MeHg; methyl mercury; MRL; minimum risk level; MUFA; mono-unsaturated fatty acid; PCB; polychlorinated biphenyls; POPs; persistent organic pollutants; PTWI; provisional tolerable weekly intake; RDI; recommended daily intake; RfD; reference dose; SFA; saturated fatty acid; TDI; tolerance daily intake; TC; total cholesterol; TG; triglyceride; WHO; World Health OrganizationRisk; Benefit; N-3 highly unsaturated fatty acid; Contaminant; Fish; Chinese market
Effect of earthworms on plant Lantana camara Pb-uptake and on bacterial communities in root-adhering soil
by My Dung Jusselme; Franck Poly; Edouard Miambi; Philippe Mora; Manuel Blouin; Anne Pando; Rouland-Lefevre Corinne Rouland-Lefèvre (pp. 200-207).
The present study aimed to assess the potential abilities of Lantana camara, an invasive plant species for phytoremediation in the presence of earthworm Pontoscolex corethrurus. Effects of earthworm on growth and lead (Pb) uptake by L. camara plant were studied in soil artificially contaminated at 500 or 1000mg of Pb kg−1 soil. This species has a promising value for phytoremediation because it can uptake as much as 10% of 1000mgkg−1 of Pb per year. Moreover, the presence of earthworms enhanced plant biomass by about 1.5–2 times and increased the uptake of lead by about 2–3 times. In the presence of earthworm, L. camara was thus able to uptake up 20% of Pb presence in the soil, corresponding to remediation time of 5years if all organs are removed. As soil microorganisms are known to mediate many interactions between earthworms and plants, we documented the effect of earthworms on the bacterial community of root-adhering soil of L. camara. Cultivable bacterial biomass of root-adhering soil increased in the presence of earthworms. Similar trend was observed on bacterial metabolic activities. The increase of lead concentrations from 500 to 1000mgkg−1 did not have any significant effect either on plant growth or on bacterial biomass and global activities but affected the structure and functional diversity of the bacterial community. These results showed that we should broaden the ecological context of phytoremediation by considering plant/microbial community/earthworm interactions that influence the absorption of heavy metals.
Keywords: Earthworms; Lantana camara; Microbial community; Functional diversity; Phytoextraction; Heavy metal
Genotoxic effects in blood cells of Mus musculus and Iguana iguana living near coal mining areas in Colombia
by Maria Cabarcas-Montalvo; Jesus Olivero-Verbel; Homer Corrales-Aldana (pp. 208-214).
Coal is a mixture of chemicals with the capacity of promoting biochemical changes that may lead to DNA damage. In this study, the comet assay in peripheral blood cells, and the micronucleus test in blood smears were used to evaluate potential genotoxic effects derived from exposure to coal mining activities on wild populations of Mus musculus and Iguana iguana. Four locations from Colombia were evaluated: La Loma and La Jagua de Ibirico, two municipalities located near coal mining fields at the Department of Cesar; and Valledupar and Arjona, cities used as reference sites, both localized at least 100 and 200km far from the mines, respectively. Compared to Valledupar and Arjona, animals collected in close proximity to coal mining areas showed highest percentages of DNA damage for both species, evidencing that living around coal mining fields may result in an increase of DNA lesions in blood cells of rodents and reptiles. The results for micronucleus test were conflicting. Mice from Arjona had greater number of cells with micronucleus than those from the other studied locations, probably as a result of infection found by blood parasites. In summary, it was demonstrated that animals living around coal mining areas have a greater chance of having DNA damage, as measured by the comet assay, than those from sites far from the coal dust source.► Living near coal mining areas may increase DNA damage in blood cells of wild mice and iguanas. ► M. musculus and I. iguana showed to be sensitive and suitable to investigate environmental genotoxicity derived from coal mining activities. ► Comet assay seems to be more sensitive and specific to detect DNA damage than the micronucleus test in blood cells.
Keywords: Coal mining; Comet assay; DNA damage; Micronucleus test; Genotoxicity; Environmental monitoring
Patterns of metal composition and biological condition and their association in male common carp across an environmental contaminant gradient in Lake Mead National Recreation Area, Nevada and Arizona, USA
by Patino Reynaldo Patiño; Michael R. Rosen; Erik L. Orsak; Steven L. Goodbred; Thomas W. May; David Alvarez; Kathy R. Echols; Carla M. Wieser; Shane Ruessler; Leticia Torres (pp. 215-224).
There is a contaminant gradient in Lake Mead National Recreation Area (LMNRA) that is partly driven by municipal and industrial runoff and wastewater inputs via Las Vegas Wash (LVW). Adult male common carp ( Cyprinus carpio; 10 fish/site) were collected from LVW, Las Vegas Bay (receiving LVW flow), Overton Arm (OA, upstream reference), and Willow Beach (WB, downstream) in March 2008. Discriminant function analysis was used to describe differences in metal concentrations and biological condition of fish collected from the four study sites, and canonical correlation analysis was used to evaluate the association between metal and biological traits. Metal concentrations were determined in whole-body extracts. Of 63 metals screened, those initially used in the statistical analysis were Ag, As, Ba, Cd, Co, Fe, Hg, Pb, Se, Zn. Biological variables analyzed included total length (TL), Fulton's condition factor, gonadosomatic index (GSI), hematocrit (Hct), and plasma estradiol-17β and 11-ketotestosterone (11kt) concentrations. Analysis of metal composition and biological condition both yielded strong discrimination of fish by site (respective canonical model, p<0.0001). Compared to OA, pairwise Mahalanobis distances between group means were WBp<0.0003); with As, Ba, Hg, and Zn, and TL, 11kt, and Hct being the primary contributors to the association. In conclusion, male carp collected along a contaminant gradient in LMNRA have distinct, collection site-dependent metal and morpho-physiological profiles that are significantly associated with each other. These associations suggest that fish health and reproductive condition (as measured by the biological variables evaluated in this study) are influenced by levels of certain metals in the Lake Mead environment.► Body metal concentrations separated male carp in LMNRA according to collection site. ► Biological conditions also separated male carp in LMNRA according to collection site. ► Variability in metal concentrations substantially explained variability in biological condition. ► The health and reproductive condition of male carp may be influenced by its metal profile.
Keywords: Abbreviations; 11kt; 11-ketotestosterone; CANCOR; canonical correlation analysis; CF; Fulton's condition factor; D; 2; Mahalanobis distance; DFA; discriminant function analysis; Estradiol-17β; E2; GSI; gonadosomatic index; Hct; hematocrit; LVB; Las Vegas Bay; LMNRA; Lake Mead National Recreation Area; LVW; Las Vegas Wash; WB; Willow BeachFish; Metals; Morphology; Physiology; Endocrine disruption
Using group-specific PCR to detect predation of mayflies (Ephemeroptera) by wolf spiders (Lycosidae) at a mercury-contaminated site
by Weston T. Northam; Lizabeth A. Allison; Daniel A. Cristol (pp. 225-231).
Bioaccumulation of contaminants can occur across ecosystem boundaries via transport by emergent aquatic insects. In the South River, Virginia, USA, aquatic mercury has contaminated songbirds nesting in adjacent riparian forests. Spiders contribute the majority of mercury to these songbirds’ diets. We tested the hypothesis that massive annual mayfly emergences provide a vector for mercury from river sediments to the Lycosid spiders most frequently eaten by contaminated songbirds. We designed mayfly-specific PCR primers that amplified mtDNA from 76% of adult mayflies collected at this site. By combining this approach with an Agilent 2100 electrophoresis system, we created a highly sensitive test for mayfly predation by Lycosids, commonly known as wolf spiders. In laboratory spider feeding trials, mayfly DNA could be detected up to 192h post-ingestion; however, we detected no mayfly predation in a sample of 110 wolf spiders collected at the site during mayfly emergence. We suggest that mayfly predation is not an important mechanism for dietary transfer of mercury to wolf spiders and their avian predators at the South River. Instead, floodplain soil should be considered as a potential proximate source for mercury in the terrestrial food web.Display Omitted► Aquatic mercury has contaminated songbirds, whose diets are composed mainly of spiders. ► No mayfly mtDNA was found in gut contents of spiders in the area. ► Mayflies are unlikely sources of dietary mercury for contaminated spiders. ► Floodplain soil may be the proximate source for mercury in the terrestrial food web.
Keywords: Mercury; Spider predation; Group-specific PCR; Mayfly; Ephemeroptera; Araneae
Can Chlorella pyrenoidosa be a bioindicator for hazardous solid waste detoxification?
by Li-Fang Hu; Yu-Yang Long; Dong-Sheng Shen; Chen-Jing Jiang (pp. 232-238).
Four kinds of solid waste residue (SWR, S1 to S4) from different stages in a sequential detoxification process were chosen. The biotoxicity of the leachates from S1 to S4 was tested by Chlorella pyrenoidosa. The growth inhibition, the chlorophyll a (chl a) and chlorophyll b (chl b) concentrations, and the ultrastructural morphology of cells of C. pyrenoidosa were studied. It shows that the growth inhibition of C. pyrenoidosa significantly increased with increasing leachate concentration when exposed to the leachates from S1, S2, S3, and S4, respectively. It well reflects the toxicity difference of leachate from SWR at different treatment stages, namely S1>S2>S3>S4. Correspondingly, the chl a and chl b concentrations of C. pyrenoidosa increased gradually as SWR was treated deeply. Leachate disrupted chlorophyll synthesis and inhibited cell growth. The changing of the ultrastructural morphology of cells under different leachate exposures, such as volume of chloroplasts and quantity of thylakoids reducing, confirmed the toxicity decrease of leachates from different stages. C. pyrenoidosa is a good bioindicator for hazardous solid waste detoxification. The EC50 at difference scenarios also suggests that it was feasible to estimate ecological toxicity of leachates to C. pyrenoidosa after exposure times of 72h. C. pyrenoidosa can be introduced to evaluate the effect of hazardous solid waste disposal by biotoxicity assessment.► The detoxification process of hazardous solid waste was evaluated by Chlorella pyrenoidosa. ► The best exposure time of ecological toxicity assessment of Chlorella pyrenoidosa was presented. ► The possible toxicity of the hazardous solid waste at different disposal stage on Chlorella pyrenoidosa was explored from cell tissue.
Keywords: Hazardous waste; Chlorella pyrenoidosa; Biotoxicity; Detoxification
New soil composition data for Europe and Australia: Demonstrating comparability, identifying continental-scale processes and learning lessons for global geochemical mapping
by Clemens Reimann; Patrice de Caritat (pp. 239-252).
New geochemical data from two continental-scale soil surveys in Europe and Australia are compared. Internal project standards were exchanged to assess comparability of analytical results. The total concentration of 26 oxides/elements (Al2O3, As, Ba, CaO, Ce, Co, Cr, Fe2O3, Ga, K2O, MgO, MnO, Na2O, Nb, Ni, P2O5, Pb, Rb, SiO2, Sr, Th, TiO2, V, Y, Zn, and Zr), Loss On Ignition (LOI) and pH are demonstrated to be comparable. Additionally, directly comparable data for 14 elements in an aqua regia extraction (Ag, As, Bi, Cd, Ce, Co, Cs, Cu, Fe, La, Li, Mn, Mo, and Pb) are provided for both continents. Median soil compositions are close, though generally Australian soils are depleted in all elements with the exception of SiO2 and Zr. This is interpreted to reflect the generally longer and, in places, more intense weathering in Australia. Calculation of the Chemical Index of Alteration (CIA) gives a median value of 72% for Australia compared to 60% for Europe. Element concentrations vary over 3 (and up to 5) orders of magnitude.Several elements (total As and Ni; aqua regia As, Co, Bi, Li, Pb) have a lower element concentration by a factor of 2–3 in the soils of northern Europe compared to southern Europe. The break in concentration coincides with the maximum extent of the last glaciation. The younger soils of northern Europe are more similar to the Australian soils than the older soils from southern Europe. In Australia, the central region with especially high SiO2 concentrations is commonly depleted in many elements.The new data define the natural background variation for two continents on both hemispheres based on real data. Judging from the experience of these two continental surveys, it can be concluded that analytical quality is the key requirement for the success of global geochemical mapping.► New continental-scale soil geochemistry data are provided for Australia and Europe. ► Procedures to guarantee comparability of the datasets are demonstrated. ► Element concentrations show 3 to 5 orders of magnitude variation on both continents. ► The data provided define the soil geochemical background at the continental scale. ► Tight analytical quality control is a key requirement for global geochemical mapping.
Keywords: Regolith; Topsoil; Geochemistry; Major elements; Trace elements; Quality control
Occurrence of synthetic musk fragrances in effluent and non-effluent impacted environments
by Darcy A. Chase; Adcharee Karnjanapiboonwong; Yu Fang; George P. Cobb; Audra N. Morse; Todd A. Anderson (pp. 253-260).
Synthetic musk fragrances (SMFs) are considered micropollutants and can be found in various environmental matrices near wastewater discharge areas. These emerging contaminants are often detected in wastewater at low concentrations; they are continuously present and constitute a constant exposure source. Objectives of this study were to investigate the environmental fate, transport, and transformation of SMFs. Occurrence of six polycyclic musk compounds (galaxolide, tonalide, celestolide, phantolide, traseolide, cashmeran) and two nitro musk compounds (musk xylene and musk ketone) was monitored in wastewater, various surface waters and their sediments, as well as groundwater, soil cores, and plants from a treated wastewater land application site. Specifically, samples were collected quarterly from (1) a wastewater treatment plant to determine initial concentrations in wastewater effluent, (2) a storage reservoir at a land application site to determine possible photolysis before land application, (3) soil cores to determine the amount of sorption after land application and groundwater recharge to assess lack thereof, (4) a lake system and its sediment to assess degradation, and (5) non-effluent impacted local playa lakes and sediments to assess potential sources of these compounds. All samples were analyzed using gas chromatography coupled with mass spectrometry (GC–MS). Data indicated that occurrence of SMFs in effluent-impacted environments was detectable at ng/L and ng/g concentrations, which decreased during transport throughout wastewater treatment and land application. However, unexpected concentrations, ng/L and ng/g, were also detected in playa lakes not receiving treated effluent. Additionally, soil cores from land application sites had ng/g concentrations, and SMFs were detected in plant samples at trace levels. Galaxolide and tonalide were consistently found in all environments. Information on occurrence is critical to assessing exposure to these potential endocrine disrupting compounds. Such information could provide a scientific framework for establishing the need for environmental regulations.► Synthetic musk fragrances were detected in effluent impacted environments. ► Synthetic musk fragrances were detected in non-effluent impacted environments. ► Galaxolide and tonalide were the most prevalent for both environments. ► Stir-bar Sorptive Extraction (SBSE) was used to detect galaxolide in plants. ► Detection of musks in playas was attributed to atmospheric deposition.
Keywords: Synthetic musk fragrances; Pharmaceuticals and personal care products (PPCPs); Land application; Playas; Stir-bar sorptive extraction (SBSE)
Platinum group elements (Pt, Pd, Rh) in airborne particulate matter in rural vs. urban areas of Germany: Concentrations and spatial patterns of distribution
by Fathi Zereini; Heiko Alsenz; Clare L.S. Wiseman; Puttmann Wilhelm Püttmann; Eberhard Reimer; Ruprecht Schleyer; Elke Bieber; Markus Wallasch (pp. 261-268).
This study examines platinum group element concentrations (PGE) (i.e. platinum (Pt), palladium (Pd) and rhodium (Rh)) and their spatial distribution in airborne particulate matter fractions (PM) of human health concern in urban and rural areas of Germany. Fractionated airborne dust and PM10, PM2.5 and PM1 samples were collected along a busy road in Frankfurt am Main from July 2008 to April 2010. PM10 was also sampled in Deuselbach and Neuglobsow between January 2008 and July 2009 to examine their concentrations at rural locations and potential for long-range transport.Pt, Pd and Rh were isolated and pre-enriched in samples using a combination of Te and Hg co-precipitation methods. Concentrations were determined using isotope dilution ICP-Q-MS (in collision mode with He).The highest airborne PGE concentrations were measured in PM10 from Frankfurt (e.g. 12.4pg Pt/m3 (mean)), while the rural locations of Deuselbach and Neuglobsow exhibited the lowest levels (e.g. 2pg Pt/m3 (mean)). PGE concentrations were observed to decline with increasingly smaller PM size fractions from PM10 to PM1. All size fractions generally contained higher levels of Pd compared to Pt and Rh, an element of greater concern due to its solubility. PM2.5 collected in Frankfurt had a mean of 16.1pg Pd/m3, compared to 9.4pg/m3 for Pt. PGE concentrations also demonstrated a distinct seasonal relationship, with the greatest levels occurring in winter. Compared to a previous study in 2002, PGE concentrations in fractionated airborne dust have significantly increased over time. Elevated PGE levels were also measured for PM10 sampled in Neuglobsow and Deuselbach, which could not be attributed to local emission sources. Using the diagnostic meteorological model, CALMET, trajectory analyses confirmed our hypothesis that PGE are being transported over longer distances from other areas of Europe.► Platinum group element (PGE) levels in airborne PM of human health concern have increased with time. ► Data on platinum (Pt), rhodium (Rh) and palladium (Pd) levels in PM1 reported for first time. ► PGE concentrations in rural areas of Germany do not reflect local emission sources. ► PGE are likely transported long-distances from urban to rural locations. ► PGE concentrations in airborne PM are higher in winter compared to summer.
Keywords: Platinum group elements (PGE); Airborne particulate matter (PM; 10; PM; 2.5; and PM; 1; ); Atmospheric transport; ICP-MS; CALMET
Relationships between congener distribution patterns of PCDDs, PCDFs, PCNs, PCBs, PCBzs and PCPhs formed during flue gas cooling
by Stina Jansson; Patrik L. Andersson (pp. 269-275).
The congener patterns of mono- to octa-chlorinated dibenzo- p-dioxins (PC1–8DD), dibenzofurans (PC1–8DF), naphthalenes (PC1–8N), mono- to deca-chlorinated biphenyls (PC1–10B), di- to hexa-chlorinated benzenes (PC2–6Bz) and mono- to penta-chlorinated phenols (PC1–5Ph) in flue gas samples collected simultaneously at 450°C, 300°C and 200°C in the post-combustion zone during waste incineration in a laboratory-scale reactor in a previous study, were in this study evaluated using principal component analysis (PCA). To our knowledge this is the most comprehensive chemical and multivariate analysis to date of the thermal formation of dioxins. The PCA indicated that different formation pathways occur in the temperature regions 450–300°C and 300–200°C, and reflected a chlorination effect of PCDF and PCDD between 450°C and 200°C which could not be discerned or was less pronounced for the other compound groups. Toxic equivalents (TEQs) of PCDDs, PCDFs and PCBs, as well as total TEQ values (TEQTotal) were also calculated, and correlations between changes in levels of specific congeners and the TEQs were explored in the PCA. Levels of four HxCDF congeners and 1,2,3,4,8-, 1,2,3,7,8-PeCDF and 2,3,4,7,8-PeCDF showed the strongest correlations with TEQTotal (R2≥0.9). In addition, levels of 1,2,4-TriCBz correlated strongly with TEQTotal (R2>0.7), supporting previous reports that it may be a potential indicator of the TEQ.► Different pathways dominating between 450–300°C and 300–200°C, respectively. ► Chlorination of PCDD/Fs between 450°C and 200°C but not for the other chloroaromatics. ► Best TEQTotal correlations for four HxCDFs, and 1,2,3,4,8-/1,2,3,7,8- and 2,3,4,7,8-PeCDF. ► 1,2,4-TriCBz correlated strongly with TEQTotal (R2>0.7) and may be a future TEQ indicator.
Keywords: Abbreviations; MSW; Municipal solid waste; PCA; Principal component analysis; PCB; Polychlorinated biphenyl; PCBz; Polychlorinated benzene; PCDD; Polychlorinated dibenzo-; p; -dioxin; PCDF; Polychlorinated dibenzofuran; PCN; Polychlorinated naphthalene; PCPh; Polychlorinated phenolCongener patterns; Principal component analysis; Waste combustion; Laboratory-scale reactor
The historical ecology of Namibian rangelands: Vegetation change since 1876 in response to local and global drivers
by Richard F. Rohde; M. Timm Hoffman (pp. 276-288).
The influence of both local and global drivers on long-term changes in the vegetation of Namibia's extensive rangelands was investigated. Fifty-two historical photographs of the Palgrave Expedition of 1876 were re-photographed and used to document changes over more than 130years, in grass, shrub and tree cover within three major biomes along a 1200km climatic gradient in central and southern Namibia. We showed that patterns of change are correlated with mean annual precipitation (MAP) and that below a threshold of around 250mm, vegetation has remained remarkably stable regardless of land-use or tenure regime. Above this threshold, an increase in tree cover is linked to the rainfall gradient, the legacies of historical events in the late 19th century, subsequent transformations in land-use and increased atmospheric CO2. We discuss these findings in relation to pastoral and settler societies, paleo- and historical climatic trends and predictions of vegetation change under future global warming scenarios. We argue that changes in land-use associated with colonialism (decimation of megaherbivores and wildlife browsers; fire suppression, cattle ranching), as well as the effects of CO2 fertilisation provide the most parsimonious explanations for vegetation change. We found no evidence that aridification, as projected under future climate change scenarios, has started in the region. This study provided empirical evidence and theoretical insights into the relative importance of local and global drivers of change in the savanna environments of central and southern Namibia and global savanna ecosystems more generally.► Innovative repeat photograph methods authenticate regional historical ecology. ► Legacy of colonial ecological impacts persists in the landscape. ► Above 250mm positive correlation between MAP and % tree cover change. ► Relative importance of local/global drivers of change in savannas analysed. ► Past trends of change are at odds with future climate change trajectories.
Keywords: Repeat photography; Climate change; Bush encroachment; Colonial ecological revolution; Savanna ecology; Pastoralism
Options to reduce greenhouse gas emissions during wastewater treatment for agricultural use
by Pinchas Fine; Efrat Hadas (pp. 289-299).
Treatment of primarily-domestic sewage wastewater involves on-site greenhouse gas (GHG) emissions due to energy inputs, organic matter degradation and biological nutrient removal (BNR). BNR causes both direct emissions and loss of fertilizer value, thus eliminating possible reduction of emissions caused by fertilizer manufacture. In this study, we estimated on-site GHG emissions under different treatment scenarios, and present options for emission reduction by changing treatment methods, avoiding BNR and by recovering energy from biogas. Given a typical Israeli wastewater strength (1050mg CODl−1), the direct on-site GHG emissions due to energy use were estimated at 1618 and 2102g CO2-eqm−3, respectively, at intermediate and tertiary treatment levels. A potential reduction of approximately 23–55% in GHG emissions could be achieved by fertilizer preservation and VS conversion to biogas. Wastewater fertilizers constituted a GHG abatement potential of 342g CO2-eqm−3. The residual component that remained in the wastewater effluent following intermediate (oxidation ponds) and enhanced (mechanical–biological) treatments was 304–254g CO2-eqm−3 and 65–34g CO2-eqm−3, respectively. Raw sludge constituted approximately 47% of the overall wastewater fertilizers load with an abatement potential of 150g CO2-eqm−3 (385kg CO2-eq dry tonne−1). Inasmuch as anaerobic digestion reduced it to 63g CO2-eqm−3 (261kg CO2-eq dry tonne−1), the GHG abatement gained through renewable biogas energy (approx. 428g CO2-eqm−3) favored digestion. However, sludge composting reduced the fertilizer value to 17g CO2-eqm−3 (121kg CO2-eq dry tonne−1) or less (if emissions, off-site inputs and actual phytoavailability were considered). Taking Israel as an example, fully exploiting the wastewater derived GHG abatement potential could reduce the State overall GHG emissions by almost 1%. This demonstrates the possibility of optional carbon credits which might be exploited in the construction of new wastewater treatment facilities, especially in developing countries.► Sewage treatment causes GHGs emissions from energy inputs, organic matter degradation and biological nutrient removal. ► Changes of treatment methods and extent can reduce direct on-site GHG emissions by up to 55%. ► Wastewater treatment and products' fertilizer value should accommodate intended agricultural reuse. ► Exploiting the wastewater derived GHG abatement potential would reduce the State of Israel overall GHG emissions by ≈1%.
Keywords: Abbreviations; ASB; alkaline stabilized biosolids; BNR; Biological nutrient removal; BOD; biochemical oxygen demand; COD; chemical oxygen demand; FDGHGAP; fertilizer-derived GHG abatement potential; GHGAP; GHG abatement potential; GHGs; greenhouse gasses; MBT; mechanical–biological treatment; OC; organic carbon; PFRP; processes to further reduce pathogens; SAT; soil aquifer treatment; TSS; total suspended solids; VAR; vector attraction reduction; VS; volatile solids; WWP; wastewater product(s); WWT(Fs); wastewater treatment (facilities)Biological nutrient removal (BNR); Biosolids; Effluent irrigation; Biogas; Energy recovery; Fertilizer recovery
Phytoplankton composition, growth and production in the Guadiana estuary (SW Iberia): Unraveling changes induced after dam construction
by Rita B. Domingues; Ana B. Barbosa; Ulrich Sommer; Galvao Helena M. Galvão (pp. 300-313).
Water quality and quantity problems in the Guadiana estuary due to a recently built dam have been predicted, including an enhancement of cyanobacteria blooms. The main goal of this work was thus to describe the present phytoplankton dynamics in relation to its environmental drivers and to evaluate the effects of damming on phytoplankton in the Guadiana estuary. Sampling campaigns were conducted during 2007–2009 in 4 locations of the Guadiana estuary, covering the salinity gradient. Phytoplankton-related and physical–chemical variables were analyzed. Throughout our study, light availability was mainly controlled by suspended sediments and it was much lower than saturating intensities described for phytoplankton growth. Therefore, light was probably limiting to phytoplankton growth throughout the year, especially in the middle and upper estuarine zones. Nitrogen limitation of phytoplankton growth occurred occasionally throughout the study period, especially during spring and summer. Overall, light and nutrient availability were mainly controlled by river flow; anthropogenic sources of nutrients to the estuary were negligible. Phytoplankton showed a unimodal cycle with biomass maximum in late spring/early summer, and the typical seasonal succession of freshwater phytoplankton (diatoms, green algae, cyanobacteria) was observed. Diatoms were the main component of the phytoplankton community and their variability closely followed nitrate and river flow variability. The relative abundance of the main phytoplankton groups changed in relation to the period before dam construction, with a decrease on cyanobacteria contribution to total abundance. The environmental perturbation induced by dam construction has now stabilized and resulted in an overall decrease in nutrient concentrations, an increase in light availability and a decrease in cyanobacteria abundance.► Dam construction is expected to significantly alter estuarine dynamics. ► The effects of dam construction on phytoplankton were analyzed. ► Light and nutrient availability were mainly controlled by river flow. ► No changes in phytoplankton composition were observed. ► Cyanobacteria abundance decreased after dam construction.
Keywords: Phytoplankton; Dam construction; Estuaries; Nutrients; Light; Anthropogenic impacts
Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects
by Ibanez Carles Ibáñez; Carles Alcaraz; Nuno Caiola; Albert Rovira; Rosa Trobajo; Miguel Alonso; Concha Duran; Jimenez Pere J. Jiménez; Munne Antoni Munné; Narcís Prat (pp. 314-322).
The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated.► We show a regime shift in a large river from phytoplankton to macrophyte dominance. ► Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. ► Phosphorus depletion is found to be the main cause of the phytoplankton decline. ► We conclude that oligotrophication triggered the colonization of macrophytes. ► This new regime shift in a river is similar to that described in shallow lakes.
Keywords: Regime shift; Phosphorus; Phytoplankton; Macrophytes; Bottom-up; Top-down
Temperature dependence of denitrification in phototrophic river biofilms
by Bouletreau S. Boulêtreau; E. Salvo; E. Lyautey; S. Mastrorillo; F. Garabetian (pp. 323-328).
Denitrification is an ecosystem service of nitrogen load regulation along the terrestrial–freshwater–marine continuum. The present study documents the short-term temperature sensitivity of denitrification enzyme activity in phototrophic river biofilms as a typical microbial assemblage of this continuum. Denitrification measurements were performed using the acetylene inhibition method at four incubation temperatures: 1.1, 12.1, 21.2 and 30.9°C. For this range of temperature, N2O production could be fitted to an exponential function of incubation temperature, yielding mean (±standard error) activation energy of 1.42 (±0.24) eV and Q10 of 7.0 (±1.4). This first quantification of denitrification enzyme activity temperature dependence in phototrophic river biofilms compares with previous studies performed in soils and sediments. This demonstrates the high temperature dependence of denitrification as compared to other community-level metabolisms such as respiration or photosynthesis. This result suggests that global warming can unbalance natural community metabolisms in phototrophic river biofilms and affect their biogeochemical budget.► We measure temperature dependence of denitrification in phototrophic river biofilms. ► We compare it to those from other microbial assemblages and metabolisms. ► It is more variable and higher than primary production and respiration. ► Global warming can unbalance the biogeochemical budget of phototrophic river biofilms.
Keywords: Potential denitrification; Temperature sensitivity; Warming; Metabolism; Epilithon; Periphyton
Assessment of Kalman filter bias-adjustment technique to improve the simulation of ground-level ozone over Spain
by V. Sicardi; J. Ortiz; Rincon A. Rincón; O. Jorba; M.T. Pay; Gasso S. Gassó; J.M. Baldasano (pp. 329-342).
The CALIOPE air quality modelling system has been used to diagnose ground level O3 concentration for the year 2004, over the Iberian Peninsula. We investigate the improvement in the simulation of daily O3 maximum by the use of a post-processing such as the Kalman filter bias-adjustment technique. The Kalman filter bias-adjustment technique is a recursive algorithm to optimally estimate bias-adjustment terms from previous measurements and model results. The bias-adjustment technique improved the simulation of daily O3 maximum for the entire year and the all the stations considered over the whole domain. The corrected simulation presents improvements in statistical indicators such as correlation, root mean square error, mean bias, and gross error. After the post-processing the exceedances of O3 concentration limits, as established by the European Directive 2008/50/CE, are better reproduced and the uncertainty of the modelling system, as established by the European Directive 2008/50/CE, is reduced from 20% to 7.5%. Such uncertainty in the model results is under the established EU limit of the 50%. Significant improvements in the O3 timing and amplitude of the daily cycle are also observed after the post-processing. The systematic improvements in the O3 maximum simulations suggest that the Kalman filter post-processing method is a suitable technique to reproduce accurate estimate of ground-level O3 concentration. With this study we evince that the adjusted O3 concentrations obtained after the post-process of the results from the CALIOPE system are a reliable means for real near time O3 forecasts.► CALIOPE modeling system simulates primary and secondary pollutants over Spain. ► Bias-adjustment technique based on Kalman filter (KF) improves the model results. ► KF post-processing leads to strong improvement in the diagnosis of ozone maximum. ► Evaluation of the modeling system meets the criteria for an acceptable performance. ► The air quality targets claimed in the European Directive 2008/50/CE are met
Keywords: Air quality; Modelling system; Ozone maximum; Kalman filter
Development of a model for radon concentration in indoor air
by Bjørn Petter Jelle (pp. 343-350).
A model is developed for calculation of the radon concentration in indoor air. The model takes into account various important parameters, e.g. radon concentration in ground, radon diffusion resistance of radon barrier, air permeance of ground, air pressure difference between outdoor ground and indoor at ground level, ventilation of the building ground and number of air changes per hour due to ventilation. Characteristic case studies are depicted in selected 2D and 3D graphical plots for easy visualization and interpretation. The radon transport into buildings might be dominated by diffusion, pressure driven flow or a mixture of both depending on the actual values of the various parameters. The results of our work indicate that with realistic or typical values of the parameters, most of the transport of radon from the building ground to the indoor air is due to air leakage driven by pressure differences through the construction. By incorporation of various and realistic values in the radon model, valuable information about the miscellaneous parameters influencing the indoor radon level is gained. Hence, the presented radon model may be utilized as a simple yet versatile and powerful tool for examining which preventive or remedial measures should be carried out to achieve an indoor radon level below the reference level as set by the authorities.► Model development for calculation of radon concentration in indoor air. ► Radon model accounting for various important parameters. ► Characteristic case studies depicted in 2D and 3D graphical plots. ► May be utilized for examining radon preventive measures.
Keywords: Radon; Radon resistance; Radon diffusion; Air leakage; Modeling; Indoor air
Effects of nitrogen deposition on carbon sequestration in Chinese fir forest ecosystems
by Xiaohua Wei; Juan A. Blanco; Hong Jiang; J.P. Hamish Kimmins (pp. 351-361).
Nitrogen deposition and its ecological effects on forest ecosystems have received global attention.We used the ecosystem model FORECAST to assess the effects of nitrogen deposition on carbon sequestration in Chinese fir planted forests in SE China. This topic is important as China is intensifying its reforestation efforts to increase forest carbon sequestration for combating climate change impacts, using Chinese fir as the most important plantation species. A series of scenarios including seven N deposition levels (1, 5, 10, 20, 30, 40 and 50kgha−1y−1), three management regime (rotation lengths of 15, 30 and 50years) and two site qualities (nutrient poor and fertile sites) were defined for the simulations. Our results showed that N deposition increased carbon sequestration in Chinese fir forests, but the efficiency of the increasing effect is reduced as N deposition levels increase. When N deposition levels exceeded 20–30kgha−1y−1, the incremental effects of N deposition on forest C pools were marginal. This suggests that N deposition levels above 20–30kgha−1y−1 could lead to N saturation in Chinese fir forest soils. Any additional amounts of N input from deposition would likely be leached out. Total above-ground C was more sensitive to N deposition than to rotation length and site quality. It was also estimated that the contributions of N deposition to C sequestration in all Chinese fir forests in South-East China are 7.4×106MgCy−1 under the current N deposition levels (5 to 10kgha−1y−1) and could reach up to 16×106MgCy−1 if N deposition continues increasing and reaches levels of 7.5 to 15kgNha−1y−1.► The model FORECAST was used to assess the effects of N deposition on C sequestration on Chinese fir plantations. ► Chinese fir forest is the most important plantation in China. ► N deposition significantly increases C sequestration in Chinese fir forests. ► N deposition levels of 20–30kgha−1y−1 could lead to soil N saturation. ► C sequestration in Chinese fir forests could increase up to 16×106MgCy−1 under future higher N deposition.
Keywords: Nitrogen deposition; Carbon sequestration; Ecosystem modeling; Chinese fir forests; FORECAST model
On the contribution of mean flow and turbulence to city breathability: The case of long streets with tall buildings
by Jian Hang; Yuguo Li; Riccardo Buccolieri; Mats Sandberg; Silvana Di Sabatino (pp. 362-373).
This paper analyses the contribution of mean flow and turbulence to city breathability within urban canopy layers under the hypothesis that winds from rural/marine areas are sources of clean air ( inhale effect) and main contributors to local-scale pollutant dilution ( exhale effect). Using Computational Fluid Dynamics (CFD) simulations, several idealized long streets flanked by tall buildings are investigated for wind flow parallel to the street axis. Aspect ratios (building height/street width) ranging from 2 to 4 and street lengths ranging from neighborhood scales (~1km in full scale) to city scales (~10km in full scale) are analyzed. To assess the inhale effect, the age of air concept is applied to quantify the time taken by a parcel of rural/marine air to reach a reference location within the urban canopy layer. To simulate the exhale effect, removal of pollutants released from a ground level source is considered.Numerical results agree with wind tunnel observations showing that a bulk portion of rural/marine air enters the streets through windward entries, a smaller part of it leaves through street roofs and the remaining fraction blows through the street aiding pollutant dilution. Substantial differences between neighborhood-scale and city-scale configurations are found. For neighborhood-scale models, pollutant removal by rural/marine air is mainly associated to mean flow along the streets. Breathability improves in streets flanked by taller buildings since in this case more rural/marine air is captured inside canyons leading to stronger wind along the street. For city-scale models, pollutant removal due to turbulent fluctuations across street roofs competes with that due to mean flows along the street. Breathability improves in streets flanked by lower buildings in which less rural/marine air is driven out and pollutant removal by turbulent fluctuations is more effective. Based on these findings, suggestions for ventilation strategies for urban areas with tall buildings are provided.► We analyze city breathability in long streets with tall buildings. ► We used Computational Fluid Dynamics simulations and wind tunnel experiments. ► Differences between neighborhood-scale and city-scale configurations are found. ► At neighborhood-scale breathability improves in streets with taller buildings. ► At city-scale breathability improves in streets flanked by lower buildings.
Keywords: Mean flow; Turbulent fluctuations; City breathability; CFD simulations; Wind tunnel; Urban canopy layer
CMAQ predictions of tropospheric ozone in the U.S. southwest: Influence of lateral boundary and synoptic conditions
by Chune Shi; H.J.S. Fernando; Peter Hyde (pp. 374-384).
Phoenix, Arizona, has been an ozone nonattainment area for the past several years and it remains so. Mitigation strategies call for improved modeling methodologies as well as understanding of ozone formation and destruction mechanisms during seasons of high ozone events. To this end, the efficacy of lateral boundary conditions (LBCs) based on satellite measurements (adjusted-LBCs) was investigated, vis-à-vis the default-LBCs, for improving the predictions of Models-3/CMAQ photochemical air quality modeling system. The model evaluations were conducted using hourly ground-level ozone and NO2 concentrations as well as tropospheric NO2 columns and ozone concentrations in the middle to upper troposphere, with the ‘design’ periods being June and July of 2006. Both included high ozone episodes, but the June (pre-monsoon) period was characterized by local thermal circulation whereas the July (monsoon) period by synoptic influence. Overall, improved simulations were noted for adjusted-LBC runs for ozone concentrations both at the ground-level and in the middle to upper troposphere, based on EPA-recommended model performance metrics. The probability of detection (POD) of ozone exceedances (>75ppb, 8-h averages) for the entire domain increased from 20.8% for the default-LBC run to 33.7% for the adjusted-LBC run. A process analysis of modeling results revealed that ozone within PBL during bulk of the pre-monsoon season is contributed by local photochemistry and vertical advection, while the contributions of horizontal and vertical advections are comparable in the monsoon season. The process analysis with adjusted-LBC runs confirms the contributions of vertical advection to episodic high ozone days, and hence elucidates the importance of improving predictability of upper levels with improved LBCs.► Ozone prediction is stymied by various factors. ► Background ozone contributes to ozone episodes. ► We ran CMAQ using two sets of boundary conditions (LBCs) for Phoenix, USA. ► The results were improved evidently by using the LBCs derived via satellite measurement. ► Process analysis demonstrates the impacts of vertical advection and synoptic conditions.
Keywords: Models-3/CMAQ; Lateral boundary conditions; Ozone prediction; Process analysis
Large scale surveys suggest limited mercury availability in tropical north Queensland (Australia)
by Timothy D. Jardine; Ian A. Halliday; Christina Howley; Vivian Sinnamon; Stuart E. Bunn (pp. 385-393).
Little is known about the threat of mercury (Hg) to consumers in food webs of Australia's wet–dry tropics. This is despite high concentrations in similar biomes elsewhere and a recent history of gold mining that could lead to a high degree of exposure for biota. We analysed Hg in water, sediments, invertebrates and fishes in rivers and estuaries of north Queensland, Australia to determine its availability and biomagnification in food webs. Concentrations in water and sediments were low relative to other regions of Hg concern, with only four of 138 water samples and five of 60 sediment samples above detection limits of 0.1μgL−1 and 0.1μgg−1, respectively. Concentrations of Hg in fishes and invertebrates from riverine and wetland food webs were well below international consumption guidelines, including those in piscivorous fishes, likely due to low baseline concentrations and limited rates of biomagnification (average slope of log Hg vs. δ15N=0.08). A large fish species of recreational, commercial, and cultural importance (the barramundi, Lates calcarifer), had low concentrations that were below consumption guidelines. Observed variation in Hg concentrations in this species was primarily explained by age and foraging location (floodplain vs. coastal), with floodplain feeders having higher Hg concentrations than those foraging at sea. These analyses suggest that there is a limited threat of Hg exposure for fish-eating consumers in this region.► Hg concentrations in freshwaters and sediments of north Queensland were low. ► Biomagnification of Hg through riverine food webs was limited. ► Barramundi, a predatory fish, had low concentrations meaning low risk for consumers. ► Floodplain-feeding barramundi had higher Hg concentrations than coastal feeders.
Keywords: Stable isotopes; Barramundi; Cape York; Floodplain; Fishery; Gold mining
Fate of 1-(1′,4′-cyclohexadienyl)-2-methylaminopropane (CMP) in soil: Route-specific by-product in the clandestine manufacture of methamphetamine
by Raktim Pal; Mallavarapu Megharaj; K. Paul Kirkbride; Ravi Naidu (pp. 394-399).
We investigated the fate of 1-(1′,4′-cyclohexadienyl)-2-methylaminopropane (CMP) in soil. CMP is the major route-specific byproduct in the clandestine manufacture of methamphetamine (MAP) by the use of excess alkali metal (e.g., lithium) in liquid ammonia, which is commonly referred to as the “Nazi method”. This is one of the most common methods used in many countries for the illicit production of MAP. Knowledge on the fate of CMP in the terrestrial environment is essential to combat potential threats arising from illegal dumping of clandestine laboratory wastes. We report on the sorption–desorption, degradation, and metabolism patterns of CMP in three South Australian soils investigated in laboratory scale. CMP sorption in the test soils followed a Freundlich isotherm in the concentration range of 5 to 100μgmL−1. Degradation studies showed that CMP was fairly unstable in both non-sterile and sterile soils, with half-life values typically less than one week. The role of biotic and abiotic soil processes in the degradation of CMP also varied significantly between the different soils, and with the length of the incubation period. Interestingly, but not surprisingly, the results showed that the CMP was not actually degraded to any simpler compounds but transformed to more persistent MAP. Thus, the main concern with Nazi method is the potential hazard from MAP rather than CMP if wastes are disposed of into the environment.► This study investigated the fate of 1-(1′,4′-cyclohexadienyl)-2-methylaminopropane (CMP) in soils. ► CMP was fairly unstable in both non-sterile and sterile soils, with half-life values less than a week. ► CMP transforms to more persistent methylamphetamine (MAP) in soils which is a major environmental concern.
Keywords: Illicit drug; By-product; 1-(1′,4′-Cyclohexadienyl)-2-methylaminopropane; Methamphetamine; Biodegradation; Soil
Estimation of soil respiration using automated chamber systems in an oak ( Quercus mongolica) forest at the Nam-San site in Seoul, Korea
by Seung Jin Joo; Soon-Ung Park; Moon-Soo Park; Chang Seok Lee (pp. 400-409).
Soil respiration (Rsoil) is the largest component of ecosystem respiration produced by the autotrophic and heterotrophic respirations. Its variability on multiple time scales strongly depends on environmental variables such as temperature and moisture. To investigate the temporal variations of Rsoil in a cool-temperate oak ( Quercus mongolica) forest at the Nam-San site in Seoul, Korea, continuous measurements of Rsoil using the automated chamber systems, air and soil temperatures and soil moisture are made for the period from April 2010 to March 2011. The observed data indicate that the Rsoil shows a remarkable seasonal variation in accordance with temperatures with high in summer and low in winter. The Rsoil is found to be strongly correlated with soil temperature (Ts) at the 5cm depth throughout the year. However, the high fluctuation of Rsoil is found to be related with soil moisture content (Ms) during the forest growing season. The estimated annual Q10 value using the 1.5m-high air temperature is found to be 2.4 that is comparable with other studies in temperate forest ecosystems. The optimal regression equation of Rsoil with the Ts at 5cm depth and the Ms at 15cm depth is found to be Rsoil=124.3 exp (0.097Ts)−55.3 (Ms)2+2931.9 (Ms)−38516 for Ts≥0°C and Rsoil=0 for Ts<0°C with r 2=0.97, P<0.01, suggesting the importance of Ts and Ms for Rsoil. The annual total soil respiration estimated by the optimal regression equation is found to be 1264gCm−2 with a maximum of 685gCm−2 in the summer season and a minimum of 33gCm−2 in the winter season. The present study can be implemented for the determination of the carbon balance of a cool-temperate Q. mongolica forest with the provision of photosynthesis.►The optimal regression of soil respiration (Rsoil) is developed in an oak forest. ►Rsoil is closely related with the soil temperature and the soil moisture content. ►Annual total Rsoil is estimated to be 1264gCm−2.
Keywords: Carbon dioxide; Ecological experimental site; Quercus mongolica; Q; 10; value; Soil moisture content; Soil temperature
Kinetics of polychlorinated biphenyl partitioning to marine Chrysophyte Isochrysis galbana
by Fung-Chi Ko; Joel E. Baker; Kwee S. Tew (pp. 410-417).
This study focused on the uptake kinetics of polychlorinated biphenyl (PCB) congeners by the Chrysophyte, Isochrysis galbana. A gas-purging experimental system was used to maintain constant dissolved PCB concentrations. Three phases of absorption were observed: first, a rapid absorption phase within the first 15min, second, a first order process reaching the maximum concentration within 48h of exposure, and third, a plateau phase as yet to be determined with very slight increases in concentration. In this study, the percentage of the maximum concentration reached within the first phase varied from 10% to 67%, depending on the size of the PCB (as determined by molecular weight and total surface area), whereas the uptake rate (ku) during the second phase was more comparable across different PCBs. In addition, for the first phase, the bioconcentration factor (BCF) of PCBs deviated from its expected relationship with hydrophobicity, as determined by Kow, and was instead related to the molecular structure of the compound.
Keywords: PCBs; Sorption; Kinetics; Bioaccumulation; Phytoplankton; Gas-purging
Influence of releases from a fresh water reservoir on the hydrochemistry of the Tinto River (SW Spain)
by Canovas Carlos Ruiz Cánovas; Manuel Olias; Vazquez-Sune Enric Vazquez-Suñé; Carlos Ayora; Jose Miguel Nieto (pp. 418-428).
The Tinto River is an extreme case of pollution by acid mine drainage (AMD), with pH values below 3 and high sulphate, metal and metalloid concentrations along its main course. This study evaluates the impact of releases from a freshwater reservoir on the Tinto River, identifying the metal transport mechanisms. This information is needed to understand the water quality evolution in the long term, and involves the comprehension of interactions between AMD sources, freshwaters, particulate matter and sediments. This work proposes a methodology for quantifying the proportions in which the different sources are contributing. The method is based on the mass balance of solutes and accounts for the uncertainty of end-members. The impact of the releases from the Corumbel Reservoir on the hydrochemistry of the Tinto River was significant, accounting up to a 92% of river discharge. These releases provoked a sharp decrease in dissolved metal concentrations, especially for Fe (approximately 1000 fold) due to dilution and precipitation. Cadmium, Zn, Cu, Co, Ni and Al suffered a dilution to a 12–16 fold decrease while Ca, Sr, Na, Pb and Si were less affected (2–4 folds decrease). However, these releases also gave rise to an increase in particulate transport, mainly Fe, As, Cr, Ba, Pb and Ti, due to sediment remobilisation and Fe precipitation. Aluminium, Li, K, Si, Al, Ni and Sr, together with Cu were present in the particulate phase during the discharge peak. The proposed 2-component mixing model revealed the existence of non-conservative behaviour for Al, Ca, Li, Mn, Ni and Si as a consequence of the interactions between the acidic Tinto waters and the clay-rich reservoir sediments during the bottom outlet opening. These results were improved by a 3-component mixing model, introducing a new end-member to account the chemical dissolution of clay-rich sediments by acidic Tinto waters.► We study the influence of freshwater releases on the acidic Tinto river waters. ► We model mixing processes between both types of water with a new tool (MIX method). ► Water releases provoked a decrease in most dissolved pollutants in the Tinto River. ► Releases also caused an increase in particulate Fe, As, Pb, Cr and other metals. ► Hydrochemical changes in the river are well explained by a 3-component mixing model.
Keywords: Acid mine drainage; Reservoir releases; Mixing processes; Particulate pollutants; Water quality
Mercury photolytic transformation affected by low-molecular-weight natural organics in water
by Feng He; Wang Zheng; Liyuan Liang; Baohua Gu (pp. 429-435).
Mechanisms by which dissolved organic matter (DOM) mediates the photochemical reduction of Hg(II) in aquatic ecosystems are not fully understood, owing to the heterogeneous nature and complex structural properties of DOM. In this work, naturally occurring aromatic compounds including salicylic, 4-hydrobenzoic, anthranilic, 4-aminobenzoic, and phthalic acid were systematically studied as surrogates for DOM in order to gain an improved mechanistic understanding of these compounds in the photoreduction of Hg(II) in water. We show that the photoreduction rates of Hg(II) are influenced not only by the substituent functional groups such as –OH, –NH2 and –COOH on the benzene ring, but also the positioning of these functional groups on the ring structure. The Hg(II) photoreduction rate decreases in the order anthranilic acid>salicylic acid>phthalic acid according to the presence of the –NH2, –OH, –COOH functional groups on benzoic acid. The substitution position of the functional groups affects reduction rates in the order anthranilic acid>4-aminobenzoic acid and salicylic acid>4-hydroxybenzoic acid. Reduction rates correlate strongly with ultraviolet (UV) absorption of these compounds and their concentrations, suggesting that the formation of organic free radicals during photolysis of these compounds is responsible for Hg(II) photoreduction. These results provide insight into the role of low-molecular-weight organic compounds and possibly DOM in Hg photoredox transformation and may thus have important implications for understanding Hg geochemical cycling in the environment.Display Omitted► Mercury photo-redox cycling is affected by naturally-occurring organic compounds. ► Substituent functional groups and their positioning on organics are critical. ► Mercury photoreduction rates correlate to UV absorption of the organic compounds. ► Secondary reaction responsible for mercury photoreduction by non-thiolate organics. ► New insights on mercury geochemical transformation in natural ecosystems.
Keywords: Mercury; Photoreduction; Aromatic compounds; Ultra-violet (UV); Sunlight; Natural organic matter
4D imaging and quantification of pore structure modifications inside natural building stones by means of high resolution X-ray CT
by J. Dewanckele; T. De Kock; M.A. Boone; V. Cnudde; L. Brabant; M.N. Boone; G. Fronteau; L. Van Hoorebeke; P. Jacobs (pp. 436-448).
Weathering processes have been studied in detail for many natural building stones. The most commonly used analytical techniques in these studies are thin-section petrography, SEM, XRD and XRF. Most of these techniques are valuable for chemical and mineralogical analysis of the weathering patterns. However, to obtain crucial quantitative information on structural evolutions like porosity changes and growth of weathering crusts in function of time, non-destructive techniques become necessary. In this study, a Belgian historical calcareous sandstone, the Lede stone, was exposed to gaseous SO2 under wet surface conditions according to the European Standard NBN EN 13919 (2003). Before, during and after the strong acid test, high resolution X-ray tomography has been performed to visualize gypsum crust formation to yield a better insight into the effects of gaseous SO2 on the pore modification in 3D. The tomographic scans were taken at the Centre for X-ray Tomography at Ghent University (UGCT). With the aid of image analysis, partial porosity changes were calculated in different stadia of the process. Increasing porosity has been observed visually and quantitatively below the new superficial formed layer of gypsum crystals. In some cases micro-cracks and dissolution zones were detected on the grain boundaries of quartz. By using Morpho+, an in-house developed image analysis program, radial porosity, partial porosity, ratio of open and closed porosity and equivalent diameter of individual pore structures have been calculated. The results obtained in this study are promising for a better understanding of gypsum weathering mechanisms, porosity changes and patterns on natural building stones in four dimensions.► We examine structural 3D differences inside building stones as a function of time. ► Gypsum crust formation is quantified with X-ray CT in combination with image analysis. ► The amount of pores smaller than 100μm increases after weathering with SO2. ► A dissolution zone does appear 200μm below the crust.
Keywords: Weathering; Pore structure; X-ray CT; Gypsum crust; Natural building stone; Image analysis
Biomonitoring and assessment of monomethylmercury exposure in aqueous systems using the DGT technique
by O. Clarisse; G.R. Lotufo; H. Hintelmann; E.P.H. Best (pp. 449-454).
A series of laboratory experiments was conducted under realistic environmental conditions to test the ability of the Diffusive Gradient in Thin film (DGT) technique to mimic monomethylmercury (MMHg) bioaccumulation by a clam ( Macoma balthica, Baltic clam). Using isotope enriched MMHg as tracers, bioavailability was determined by comparing the rate of MMHg uptake by novel DGT devices and sentinel organism over time. Experiments were conducted under varying conditions of salinity and MMHg speciation. Depending on MMHg level and speciation in the dissolved phase, MMHg uptake rates by the sentinel organism varied greatly from 0.4 to 2.4Lg−1d−1. Reproducibilities of MMHg uptakes by DGT and clams were estimated at 7 and 38%, respectively. A significant linear relationship (log basis) between MMHg accumulation by DGT and clams was observed (r2=0.89). The study demonstrates that DGT results reasonably predict MMHg uptake by clams from the aqueous phase and provide the basis for application of the DGT device as a surrogate for sentinel organism for monitoring bioavailable MMHg.► We investigate the potential of DGT devices to act as surrogates for sentinel organism. ► We compare monomethylmercury accumulation in DGT devices and in clams from the dissolved phase. ► We examine the effects of salinity and MMHg speciation on MMHg accumulation by DGT and clams. ► For all laboratory experiments, a strong overall correlation between MMHg accumulations in clams and DGTs is observed.
Keywords: DGT; Dissolved methylmercury exposure; Clam; (Bio)-monitoring; Bioaccumulation; Bioavailability
The applicability of reflectance micro-Fourier-transform infrared spectroscopy for the detection of synthetic microplastics in marine sediments
by Jesse P. Harrison; Jesús J. Ojeda; María E. Romero-González (pp. 455-463).
Synthetic microplastics (≤5-mm fragments) are globally distributed contaminants within coastal sediments that may transport organic pollutants and additives into food webs. Although micro-Fourier-transform infrared (micro-FT-IR) spectroscopy represents an ideal method for detecting microplastics in sediments, this technique lacks a standardized operating protocol. Herein, an optimized method for the micro-FT-IR analysis of microplastics in vacuum-filtered sediment retentates was developed. Reflectance micro-FT-IR analyses of polyethylene (PE) were compared with attenuated total reflectance FT-IR (ATR-FT-IR) measurements. Molecular mapping as a precursor to the imaging of microplastics was explored in the presence and absence of 150-μm PE fragments, added to sediment at concentrations of 10, 100, 500 and 1000ppm. Subsequently, polymer spectra were assessed across plastic-spiked sediments from fifteen offshore sites. While all spectra obtained of evenly shaped plastics were typical to PE, reflectance micro-FT-IR measurements of irregularly shaped materials must account for refractive error. Additionally, we provide the first evidence that mapping successfully detects microplastics without their visual selection for characterization, despite this technique relying on spectra from small and spatially separated locations. Flotation of microplastics from sediments only enabled a fragment recovery rate of 61 (±31 S.D.) %. However, mapping 3-mm2 areas (within 47-mm filters) detected PE at spiking concentrations of 100ppm and above, displaying 69 (±12 S.D.) % of the fragments in these locations. Additionally, mapping detected a potential PE fragment in a non-spiked retentate. These data have important implications for research into the imaging of microplastics. Specifically, the sensitivity and spatial resolution of the present protocol may be improved by visualizing the entire filter with high-throughput detection techniques (e.g., focal plane array-based imaging). Additionally, since micro-FT-IR analyses depend on methods of sample collection, our results emphasize the urgency of developing efficient and reproducible techniques to separate microplastics from sediments.► We evaluate the reliability of micro-FT-IR analyses of microplastics in marine sediments. ► Micro-FT-IR analyses of microplastics in reflectance mode must account for refractive error. ► Molecular mapping successfully detects microplastics in vacuum-filtered sediment retentates. ► FT-IR analyses of plastics in polymer-spiked sediments are consistent across several field sites.
Keywords: Abbreviations; ATR; attenuated total reflectance; LDPE; low-density polyethylene; FPA; focal plane array; FT-IR; Fourier-transform infrared; UHMW PE; ultra-high molecular weight polyethyleneMicroplastics; Marine; Sediments; Detection; Infrared spectroscopy; Imaging
Experimental degradation of polymer shopping bags (standard and degradable plastic, and biodegradable) in the gastrointestinal fluids of sea turtles
by Muller Christin Müller; Kathy Townsend; Jörg Matschullat (pp. 464-467).
The persistence of marine debris such as discarded polymer bags has become globally an increasing hazard to marine life. To date, over 177 marine species have been recorded to ingest man-made polymers that cause life-threatening complications such as gut impaction and perforation. This study set out to test the decay characteristics of three common types of shopping bag polymers in sea turtle gastrointestinal fluids (GIF): standard and degradable plastic, and biodegradable. Fluids were obtained from the stomachs, small intestines and large intestines of a freshly dead Green turtle ( Chelonia mydas) and a Loggerhead turtle ( Caretta caretta). Controls were carried out with salt and freshwater. The degradation rate was measured over 49days, based on mass loss. Degradation rates of the standard and the degradable plastic bags after 49days across all treatments and controls were negligible. The biodegradable bags showed mass losses between 3 and 9%. This was a much slower rate than reported by the manufacturers in an industrial composting situation (100% in 49days). The GIF of the herbivorous Green turtle showed an increased capacity to break down the biodegradable polymer relative to the carnivorous Loggerhead, but at a much lower rate than digestion of natural vegetative matter. While the breakdown rate of biodegradable polymers in the intestinal fluids of sea turtles is greater than standard and degradable plastics, it is proposed that this is not rapid enough to prevent morbidity. Further study is recommended to investigate the speed at which biodegradable polymers decompose outside of industrial composting situations, and their durability in marine and freshwater systems.► To investigate the behaviour of plastics in sea turtle gastrointestinal fluids, experiments with three types of bags were performed over 49 days: standard, degradable and biodegradable bags. ► Biodegradable bags showed mass losses between 3 and 9%, while the degradation of the standard and the degradable plastic bags was statistically insignificant. ► The digestibility rate for the biodegradable bag (3–9%), is much less than that recorded for equivalent sized turtles consuming sponge (51–53%), implying that the breakdown rate may not be biologically significant enough to prevent a gut impaction.
Keywords: Marine debris; Digestive system; Sea turtle; Chelonia mydas; Caretta caretta; Moreton Bay
Distribution of perfluorinated compounds in Yellow-legged gull eggs ( Larus michahellis) from the Iberian Peninsula
by Joana Vicente; Albert Bertolero; Johan Meyer; Paula Viana; Silvia Lacorte (pp. 468-475).
This study is aimed to evaluate the presence and distribution of Perfluorinated Compounds (PFCs) in Yellow-legged gull eggs ( Larus michahellis) collected from 8 National or Natural Parks from the Iberian Peninsula. In each colony, 12 eggs were randomly collected and pooled from 3 areas of the colony and analyzed using liquid–solid extraction and liquid chromatography coupled to tandem mass spectrometry. Perfluorooctanate sulfonate (PFOS) was the only compound detected in the eggs and its presence was higher in the colonies situated in NE Iberian Peninsula due to the more industrial and mass urbanization in this area compared to the SW Mediterranean or Atlantic colonies. Accordingly, the Medes site, followed by the Ebro Delta and Columbretes, all situated in the NW Mediterranean coast, contained the highest PFOS levels (40.5–54.0ng/g-ww). In all other colonies, PFOS was detected at levels of 10.1–18.6ng/g-ww. Egg shell biometry was studied and it was found that the presence of PFOS did not affect the development of the egg.► PFOS was detected in L. michahellis eggs from 8 colonies in the Iberian Peninsula. ► NW Mediterranean colonies had higher PFOS concentration than Atlantic. ► Differences in egg shell parameters were found among colonies. ► No correlation was found between egg shell parameters and PFOS levels.
Keywords: Perfluorinated compounds; Yellow-legged gull; Eggs; Biomonitoring; Natural/National Parks; Eggshell parameters
Biochar influences the microbial community structure during manure composting with agricultural wastes
by Keiji Jindo; Miguel A. Sánchez-Monedero; Hernandez Teresa Hernández; Garcia Carlos García; Toru Furukawa; Kazuhiro Matsumoto; Tomonori Sonoki; Felipe Bastida (pp. 476-481).
The influence of biochar derived from a hardwood tree ( Quercus serrate Murray) on the dynamics of the microbial community during the composting of poultry manure (PM) and cow manure (CM) was evaluated by phospholipid fatty acid analysis (PLFAs). Changes in the PLFA patterns were related to key composting properties (C/N ratio, temperature, and bulk density) as the major drivers of the dynamics of the microbial community. At the beginning of the process, the fungal biomass was significantly greater in PM and CM than in the respective co-composted materials with biochar (PMB and CMB); this difference declined gradually during the process. In contrast, the Gram+ to Gram− ratio was increased by the presence of biochar. After 12weeks of composting, factor analysis based on the relative abundances of single PLFAs revealed changes in the microbial community structure which depended on the original organic wastes (CM vs PM).► The influence of biochar on the community during composting evaluated by PLFAs. ► Changes in the microbial community structure related to physic-chemical changes. ► Microbial community structure changed after 12 weeks of composting with biochar. ► Changes in the community depended on the origin of manure composted with biochar.
Keywords: Biochar; Composting; Phospholipid fatty acids; Microbial community
Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are major contributors to the persistent organobromine load in sub-Arctic and Arctic marine mammals, 1986–2009
by Anna Rotander; Bert van Bavel; Riget Frank Rigét; Audunsson Guðjón Atli Auðunsson; Anuschka Polder; Geir Wing Gabrielsen; Vikingsson Gísli Víkingsson; Bjarni Mikkelsen; Maria Dam (pp. 482-489).
A selection of MeO-BDE and BDE congeners were analyzed in pooled blubber samples of pilot whale ( Globicephala melas), ringed seal ( Phoca hispida), minke whale ( Balaenoptera acutorostrata), fin whale ( Balaenoptera physalus), harbor porpoise ( Phocoena phocoena), hooded seal ( Cystophora cristata), and Atlantic white-sided dolphin ( Lagenorhynchus acutus), covering a time period of more than 20years (1986–2009). The analytes were extracted and cleaned-up using open column extraction and multi-layer silica gel column chromatography. The analysis was performed using both low resolution and high resolution GC-MS. MeO-PBDE concentrations relative to total PBDE concentrations varied greatly between sampling periods and species. The highest MeO-PBDE levels were found in the toothed whale species pilot whale and white-sided dolphin, often exceeding the concentration of the most abundant PBDE, BDE-47. The lowest MeO-PBDE levels were found in fin whales and ringed seals. The main MeO-BDE congeners were 6-MeO-BDE47 and 2′-MeO-BDE68. A weak correlation only between BDE47 and its methoxylated analog 6-MeO-BDE47 was found and is indicative of a natural source for MeO-PBDEs.►MeO-PBDEs are major contributors to the persistent organobromine load in the analyzed marine mammal species. ►No apparent relation was found between PBDE and MeO-PBDE levels. ►The data add further support for a natural origin of MeO-PBDEs.
Keywords: Arctic; Marine mammals; North Atlantic Ocean; Polybrominated diphenyl ethers (PBDEs); Methoxylated polybrominated diphenyl ethers (MeO-PBDEs); Sub-Arctic
Cadmium and Zn availability as affected by pH manipulation and its assessment by soil extraction, DGT and indicator plants
by Iqbal Muhammad; Markus Puschenreiter; Walter W. Wenzel (pp. 490-500).
Manipulation of soil pH by soil additives and / or rhizosphere processes may enhance the efficiency of metal phytoextraction. Here we report on the effect of nitric acid additions to four polluted soils on Cd and Zn concentrations in soil solution (Csoln) and 0.005M Ca(NO3)2 extracts, and related changes in the diffusive fluxes and resupply of the metals as assessed by diffusive gradients in thin films (DGT). The responses of these chemical indicators of bioavailability were compared to metal uptake in two indicator plant species, common dandelion ( Taraxacum officinale F.H. Wigg) and narrow leaf plantain ( Plantago lanceolata L.) grown for 75days in a pot experiment.Lowering soil pH increased Csoln, the 0.005M Ca(NO3)2-soluble fractions and the DGT-measured Cd and Zn concentrations (CDGT) in the experimental soils. This was associated with enhanced uptake of Cd and Zn on soils acidified to pH 4.5 whereas plants did not survive at pH 3.5. Toxicity along with decreased kinetics of metal resupply (calculated by the 2D DIFS model) in the strong acidification treatment suggests that moderate acidification is more appropriate to enhance the phytoextraction process.Each of the chemical indicators of bioavailability predicted well (R2>0.70) the Cd and Zn concentrations in plantain shoots but due to metal toxicity not for dandelion. Concentration factors, i.e. the ratio between metal concentrations in shoots and in soil solution (CF) indicate that Cd and Zn uptake in plantain was not limited by diffusion which may explain that DGT did not perform better than Csoln. However, DGT is expected to predict plant uptake better in diffusion-limited conditions such as in the rhizosphere of metal-accumulating phytoextraction crops.► The effect of soil acidification was assessed for four Zn and Cd polluted soils. ► For some soils moderate acidification could enhance the metal uptake efficiency. ► Chemical assessment of bioavailability using soil solution and DGT was performed. ► This study provides the basis for the development of acidity-aided phytoextraction.
Keywords: Bioavailability; Soil acidification; Indicator plants; DGT; Metal resupply; Phytoextraction
Removal of bisphenol A by the freshwater green alga Monoraphidium braunii and the role of natural organic matter
by C. Eliana Gattullo; Bahrs Hanno Bährs; Christian E.W. Steinberg; Elisabetta Loffredo (pp. 501-506).
Phytoremediation of waters by aquatic organisms such as algae has been recently explored for the removal of organic pollutants possessing endocrine disrupting capacity. Monoraphidium braunii, a green alga known for rapid growth and good tolerance to different natural organic matter (NOM) qualities, was tested in this study for the ability to tolerate and remove the endocrine disruptor bisphenol A at concentrations of 2, 4 and 10mgL−1, either in NOM-free or NOM-containing media. NOM at concentrations of 2, 5 and 20mgL−1 of DOC, was added because it may interfere with xenobiotics and modify their effects, modulate algal growth performances or produce a trade-off of both effects. After 2 and 4days of algal growth, the cell number and size, the maximum quantum yield of photosystem II in the dark or light adapted state, and the chlorophyll a content were recorded in order to evaluate the algal response to bisphenol A. Moreover, the residual bisphenol A was measured in the algal cultures by chromatographic technique. Results indicated that after 2 and 4days bisphenol A at the lower concentrations was not toxic for alga, whereas at the highest concentration it reduced algal growth and photosynthetic efficiency. The sole NOM and its combinations with bisphenol A at the lower concentrations increased the cell number and the chlorophyll a content of algae. After 4-day growth, good removal efficiency was exerted by M. braunii at concentrations of 2, 4 and 10mgL−1 removing, respectively, 39%, 48% and 35% of the initial bisphenol A. Lower removal percentages were found after 2-day growth in the different treatments. NOM at any concentration scarcely influenced the bisphenol A removal. On the basis of data obtained, the use of M. braunii could be reasonably recommended for the phytoremediation of aquatic environments from bisphenol A.► The alga Monoraphidium braunii tolerates high concentrations of bisphenol A. ► The alga Monoraphidium braunii removes relevant amount of bisphenol A from water. ► Natural organic matter reduces the bisphenol A toxicity on Monoraphidium braunii. ► Natural organic matter does not reduce bisphenol A removal by Monoraphidium braunii.
Keywords: Endocrine disruptor; Bisphenol A; Phytoremediation; Monoraphidium braunii; Natural organic matter; Chlorophyll; a; fluorescence
Oxidative degradation of propachlor by ferrous and copper ion activated persulfate
by C.S. Liu; K. Shih; C.X. Sun; F. Wang (pp. 507-512).
The process of in situ chemical oxidation (ISCO) by persulfate (S2O82−) can be accelerated by metal ion activation, which more effectively degrades subsurface pollutants by enhancing sulfate radical (SO4−) generation. This study compared the results of propachlor degradation by Cu2+ and Fe2+ activated persulfate and revealed differing degradation kinetics and mechanisms between the two types of activation system. The activation of persulfate by Fe2+ ions generally resulted in rapid degradation in the early stage, but was accompanied by a dramatic decrease in efficiency due to the rapid depletion of Fe2+ by the sulfate radicals generated. In contrast, the Cu2+ activated persulfate had a longer lasting degradation effect and a proportionally greater degradation enhancement at elevated Cu2+ concentrations. An optimal Fe2+ concentration should be sought to activate the persulfate, as a high Fe2+ concentration of 2.5mM or above, as was used in this study, may inhibit propachlor degradation due to the competitive consumption of sulfate radicals by the excess Fe2+ ions. Higher temperatures (55°C compared with 30°C) resulted in enhanced metal activation, particularly with the Cu2+ activated system. Furthermore, acidic conditions were found to be more favorable for propachlor degradation by metal activated persulfate. The ecotoxicity of degraded propachlor samples, which was indicated by average well color development (AWCD) for its microbial community activity, was confirmed to be decreased during the degradation processes with these two ions activated persulfate.► Propachlor can be efficiently degraded by persulfate activated by either Cu2+ or Fe2+ ions. ► Different degradation kinetics was observed in Cu2+ and Fe2+ activated persulfate. ► Reaction conditions influence the activated persulfate differently by Cu2+ and Fe2+. ► The ecotoxicity of propachlor sample was confirmed decreased by Cu2+/Fe2+ activated persulfate.
Keywords: Persulfate activation; Propachlor; In situ chemical oxidation (ISCO); Chloroacetanilide herbicides; Pesticide detoxification
The occurrence of hazardous volatile elements and nanoparticles in Bulgarian coal fly ashes and the effect on human health exposure
by Luis F.O. Silva; Kátia DaBoit; Carlos H. Sampaio; André Jasper; Maria L. Andrade; Irena J. Kostova; Frans B. Waanders; Kevin R. Henke; James C. Hower (pp. 513-526).
Low-rank, high-mineral matter Bulgarian coals were studied using a variety of chemical, optical, and electron beam methods. The larger fly ash carbon phases include charred carbons in contrast to coked carbons present in the fly ashes of bituminous-coal-derived fly ashes. Nanoscale carbons include multi-walled carbon nanotubes (MWCNTs) encapsulating Hg, Se, and As, among other elements. In addition to the glass which dominates the fly ash, relatively coarse ‘rock fragments’, consisting of an unmelted to partially melted core surrounded by a glassy rim, are present in the fly ash. Nano-scale minerals can contain hazardous elements and, along with metal-bearing multiwalled nanotubes, can be a path for the entry of hazardous particles into the lungs and other organs.Display Omitted► We model Bulgarian power plants which have regulated minerals nanoparticles can contain hazardous elements. ► We study changes in the level of information about nanominerals importance and the effect on human health exposure. ► Increasing information will increase quality if power plants procedures are similar.
Keywords: Fly ash; Low-rank coal; Toxicity; Nanotubes
Nicotine occurrence in bottled mineral water: Analysis of 10 brands of water in Spain
by Gonzalez Alonso S. González Alonso; Valcarcel Y. Valcárcel; J.C. Montero; Catala M. Catalá (pp. 527-531).
The presence of pharmaceuticals in surface and drinking water has been evidenced in numerous studies. Despite representing one of the most common consumption sources, to the best of our knowledge, this is the first report on the presence of pharmaceutical compounds in bottled mineral water. Pollution of these sources not only could pose a serious human health risk, but would also warn about the quality of the water in our aquifers, a vital and vulnerable source of water, essential for the future water supply. Fifty eight pharmaceutically active compounds (PhACs) belonging to the 12 main therapeutic groups were analyzed in 10 bottled mineral water brands produced in Spain. Nicotine was detected in concentrations ranging from 7ngL−1 to 15ngL−1 in 5 of 10 bottled mineral waters. Despite the low nicotine concentration measured, the presence of this compound in bottled water still raises concern. Health risk assessment researchers have postulated that the risk to adult healthy humans from oral intake of nicotine at low levels is negligible. However, no studies have been conducted to assess the human health risk of vulnerable populations such as pregnant women and newborns. This population is the target of advertising on the purity and quality characteristics of bottled mineral water.
Keywords: Abbreviations; PhACs; PHarmaceutically Active CompoundS; EEA; European Environment Agency; US EPA; United States Environmental Protection AgencyBottled mineral water; Nicotine; Pharmaceuticals; Spain
Environmental assay on the effect of poultry manure application on soil organisms in agroecosystems
by M. Delgado; Rodriguez C. Rodríguez; Martin J.V. Martín; R. Miralles de Imperial; F. Alonso (pp. 532-535).
This paper reports the effects produced on the organisms of the soil (plants, invertebrates and microorganisms), after the application of two types of poultry manure (sawdust and straw bed) on an agricultural land. The test was made using a terrestrial microcosm, Multi-Species Soil System (MS3) developed in INIA. There was no difference in the germination for any of the three species of plants considered in the study. The biomass was increased in the wheat ( Triticum aestivum) coming from ground treated with both kinds of poultry manure. Oilseed rape ( Brasica rapa) was not affected and regarding vetch ( Vicia sativa) only straw poultry manure showed significant difference. For length only Vicia sativa was affected showing a reduction when straw was exposed to poultry manure. When the effect on invertebrates was studied, we observed a reduction in the number of worms during the test, especially from the ground control (13.7%), higher than in the ground with sawdust poultry manure (6.7%), whereas in the ground with straw poultry manure, there was no reduction. The biomass was affected and at the end of the test it was observed that while the reduction of worms in the ground control was about 48%, the number of those that were in the ground with sawdust poultry manure or straw poultry manure decreased by 41% and 22% respectively. Finally, the effects on microorganisms showed that the enzymatic activities: dehydrogenase (DH) and phosphatase and basal respiration rate increased at the beginning of the test, and the differences were statistically significant compared with the values of the control group. During the test, all these parameters decreased (except DH activities) but they were always higher than in the ground control. This is why it is possible to deduce that the contribution of poultry manure caused an improvement in the conditions of fertilization and also for the soil.
Keywords: Poultry manure; Multi-Species Soil System; Enzymatic activities
Incidence of poxvirus-like lesions in two estuarine dolphin populations in Australia: Links to flood events
by Christine A. Fury; John S. Reif (pp. 536-540).
We report on the incidence of poxvirus-like lesions assessed by photographic identification in two estuarine populations of bottlenose dolphins ( Tursiops aduncus) in Australia over a 3-year period. Poxvirus infections of odontocetes are characterized by pinhole or ring-like skin lesions that appear as solitary or coalesced circular gray blemishes. Environmental and physiological stressors are believed to contribute to their manifestation (Van Bressem et al., 2009b). A total of 187 boat-based surveys were completed from October 2003 to September 2006 in the Clarence River (CR) and Richmond River (RR) estuaries, with 720 dolphins sighted. Forty-six individuals, including calves, were identified in the CR and 23 in the RR. We investigated the temporal relationship between four flood events that occurred in the region during the study period and the occurrence of poxvirus-like skin lesions. Dolphin poxvirus-like lesions were not observed in these populations prior to 2004. Following flood events in 2004, 2005 and 2006, a total of 10 new cases were observed, 6 in the CR and 4 in the RR. Our data suggest that the occurrence of dolphin poxvirus-like lesions may be an indicator for climatic events such as flooding. Long-term follow-up of these estuarine populations is required to further clarify the factors leading to ‘outbreaks’ of poxvirus infections.► Incidence of lesions occurred in the subsequent season following a flood event. ► Following flood events in 2004, 2005 and 2006, a total of 10 new cases were observed in two estuaries. ► Cases were observed predominantly among younger animals that were resident dolphins. ► Occurrence of dolphin poxvirus-like lesions may be an indicator for climatic events such as flooding.
Keywords: Dolphin poxvirus; Water quality; Flood events; Tursiops aduncus; Climate; Infectious diseases