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Archives of Environmental Contamination and Toxicology (v.55, #2)
Distribution of Pesticides, PAHs, PCBs, and Bioavailable Metals in Depositional Sediments of the Lower Missouri River, USA by Kathy R. Echols; William G. Brumbaugh; Carl E. Orazio; Thomas W. May; Barry C. Poulton; Paul H. Peterman (pp. 161-172).
The lower Missouri River was studied to determine the distribution of selected persistent organic pollutants and bioavailable metals in depositional sediments. Nineteen sites between Omaha, Nebraska and Jefferson City, Missouri were sampled. This stretch of the river receives point-source and non-point-source inputs from industrial, urban, and agricultural activities. As part of an ecological assessment of the river, concentrations of 29 legacy organochlorine pesticides (OC pesticides), including chlordanes, DDTs, and hexachlorocyclohexanes; a select list of current-use pesticides, including trifluralin, diazinon, chlorpyrifos, and permethrin, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), divalent metals (copper, nickel, zinc, cadmium, and lead), and polybrominated diphenyl ethers (PBDEs) were determined. Concentrations (dry weight basis) of OC pesticides in the sediments were less than 1 ng/g, with the exception of the backwater sediment collected from the mouth of the Blue River in the Kansas City metropolitan area, which contained up to 20 ng/g total chlordane, 8.1 ng/g p,p′-DDE, 1.5 ng/g lindane, 4.8 ng/g dieldrin, and 3 ng/g endrin. Concentrations of chlorpyrifos and permethrin ranged from less than 1 ng/g to 5.5 ng/g and 44 ng/g, respectively. Concentrations of PCBs ranged from less than 11 ng/g to 250 ng/g, with the Blue River and Sibley sediments containing 100 and 250 ng/g total PCBs, respectively. Concentrations of total PAHs at 17 of the 19 sites ranged from 250 to 700 ng/g, whereas the Riverfront and Blue River sites in Kansas City contained 1100 ng/g and nearly 4000 ng/g, respectively. Concentrations of the metals did not vary significantly among most sites; however, the Blue River site contained elevated concentrations of zinc (104 μg/g), cadmium (0.7 μg/g), and lead (34 μg/g) compared to the other sites. The moderately high concentrations of acid-volatile sulfide in the sediments suggest a low potential for metal toxicity to benthic organisms along this reach of the Missouri River. The depositional area sediments contained concentrations of the targeted persistent organic chemicals and metals that were below published probable effect level concentrations.
Sediment–Porewater Partition of Nonylphenol Polyethoxylates: Field Measurements from Lanzhou Reach of Yellow River, China by Yong Yu; Jian Xu; Hongwen Sun; Shugui Dai (pp. 173-179).
Nonylphenol polyethoxylates (NPnEO) and nonylphenol (NP) have drawn much environmental concern because of their weak estrogenic activities. The present study focused on the spatial distribution of NPnEO and NP in surface sediments and their corresponding porewaters along Lanzhou Reach of Yellow River, China. Long EO chain NPnEO analogs with n > 2 were not measurable in most sediment and porewater samples, so only NP, nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) were discussed in this study. Concentrations of NP, NP1EO, and NP2EO in the sediments ranged from 61.3 to 113.9, 31.1 to 55.9, and 47.9 to 74.1 ng/g dry weight, respectively. A significant correlation (R 2 = 0.56, p < 0.01) was observed between NP levels and organic carbon content of the sediments, whereas no correlation was found for the more hydrophilic NP1EO and NP2EO. The concentrations of NP, NP1EO, and NP2EO in the porewaters ranged from 0.35 to 1.95, 0.06 to 0.63, and 0.08 to 0.38 μg/L. The mean in situ log K oc values (n = 13, S1 excluded) of NP, NP1EO, and NP2EO were 4.48, 4.94, and 5.06, respectively, which were lower than those measured in batch adsorption experiments.
Groundwater Quality Assessment Using Chemometric Analysis in the Adyar River, South India by T. Venugopal; L. Giridharan; M. Jayaprakash (pp. 180-190).
A multivariate statistical technique has been used to assess the factors responsible for the chemical composition of the groundwater near the highly polluted Adyar River. Basic chemical parameters of the groundwater have been pooled together for evaluating and interpreting a few empirical factors controlling the chemical nature of the water. Twenty-three groundwater samples were collected in the vicinity of the Adyar River. Box-whisker plots were drawn to evaluate the chemical variation and the seasonal effect on the variables. R-mode factor analysis and cluster analysis were applied to the geochemical parameters of the water to identify the factors affecting the chemical composition of the groundwater. Dendograms of both the seasons gives two major clusters reflecting the groups of polluted and unpolluted stations. The other two minor clusters and the movement of stations from one cluster to another clearly bring out the seasonal variation in the chemical composition of the groundwater. The results of the R-mode factor analysis reveal that the groundwater chemistry of the study area reflects the influence of anthropogenic activities, rock-water interactions, saline water intrusion into the river water, and subsequent percolation into the groundwater. The complex geochemical data of the groundwater were interpreted by reducing them to seven major factors, and the seasonal variation in the chemistry of water was clearly brought out by these factors. The higher concentration of heavy metals such as Fe and Cr is attributed to the rock-water interaction and effluents from industries such as tanning, chrome-plating, and dyeing. In the urban area, the Pb concentration is high due to industrial as well as urban runoff of the atmospheric deposition from automobile pollution. Factor score analysis was used successfully to delineate the stations under study with the contributing factors, and the seasonal effect on the sample stations was identified and evaluated.
Deposition of Polycyclic Aromatic Hydrocarbons (PAHs) and Their Mass Transfer Coefficients Determined at a Trafficked Site by Yücel Tasdemir; Fatma Esen (pp. 191-198).
It is difficult to determine the deposition levels of gaseous polycyclic aromatic hydrocarbons (PAHs), as even atmospheric PAHs mainly exist in the gas phase. Gaseous PAH fluxes across the air–water interface were measured in Merinos, Bursa, Turkey. Direct gaseous fluxes of PAHs were measured intermittently for the period August 2004 through May 2005 when there was no precipitation. A modified water surface sampler (WSS), including a filter holder and an XAD-2 resin column, was employed to collect the flux samples. Average gaseous PAH flux into the WSS, determined by analyzing the XAD-2 resin column, was 31,068 ± 16,035 ng m−2 d−1. This flux value was about 90% of the total (gaseous + particulate) PAH flux, which may indicate that gas exchange is a major removal mechanism for atmospheric PAHs in our sampling site. Variations in gas exchange fluxes likely resulted from changes in both meteorological conditions and concentrations whose level depends on many parameters including fuel characteristics and strength, combustion types, and their efficiencies. Vapor phase PAH fluxes were divided by ambient air concentrations measured with a high volume sampler to calculate overall gas phase PAH mass transfer coefficients (MTCs) (KG). The calculated average PAH MTC was 0.38 ± 0.17 cm s−1. The average MTC is comparable with ones calculated using a similar configuration of a WSS.
Aryl Hydrocarbon Receptor and Estrogen Receptor Ligand Activity of Organic Extracts from Road Dust and Diesel Exhaust Particulates by Kentaro Misaki; Masato Suzuki; Masafumi Nakamura; Hiroshi Handa; Mitsuru Iida; Teruhisa Kato; Saburo Matsui; Tomonari Matsuda (pp. 199-209).
A wide variety of contaminants derived from diesel and gasoline engines, tire, asphalt, and natural organic compounds is found in road dust. Polycyclic aromatic compounds (PACs) are the important toxic targets among various contents in road dust and diesel exhaust particulates (DEPs), and endocrine-disrupting activity of PACs was suggested. In the present study, aryl hydrocarbon receptor (AhR) ligand activity was confirmed in the extract of both road dust and DEPs. In the separation of the extracts for both road dust and DEPs with reversed-phase HPLC, it was found that polar fractions contributed to significant AhR ligand activity in both a mouse hepatoma (H1L1) cell system and a yeast system. Furthermore, the contribution of these polar fractions was higher in DEPs than in road dust, probably because of the greater concentration of oxy-PAHs in DEPs than in road dust. The contribution of contaminants associated with the polar region to AhR ligand activity was also evident following the separation of road dust with normal-phase HPLC. Additionally, remarkable estrogen receptor (ER) ligand activity was detected in the highly polar region separated with normal-phase HPLC. It is suggested that many unknown AhR or ER ligand active compounds are contained in the polar region.
Phosphorus Sorption Capacities and Physicochemical Properties of Nine Substrate Materials for Constructed Wetland by Lihua Cui; Xizhen Zhu; Mei Ma; Ying Ouyang; Mei Dong; Wenling Zhu; Shiming Luo (pp. 210-217).
Constructed wetland (CW) is a promising technique for removal of pollutants from wastewater and agricultural runoff. The performance of a CW to remove pollutants, however, hinges on the use of suitable substrate materials. This study examined the physicochemical properties and phosphorus (P) sorption capacities of nine different CW substrate materials using both batch experiments and the Freundlich as well as the Langmuir isotherm. The nine substrate materials used in this study were turf, topsoil, gravel, midsized sand (MSS), blast furnace slag (BFS), coal burn slag (CBS), blast furnace artificial slag (BFAS), coal burn artificial slag (CBAS), and midsized artificial sand (MSAS). Experimental data showed that sorption of P increased with initial solution P concentrations for all nine substrate materials. The maximum P sorption capacity of the substrate materials estimated by Langmuir isotherm was in the following order: turf (4243 mg/kg substrate) > BFAS (2116 mg/kg substrate) > BFS (1598 mg/kg substrate) > CBS (1449 mg/kg substrate) > top soil (1396 mg/kg substrate) > CBAS (1194 mg/kg substrate) > MSAS (519 mg/kg substrate) > gravel (494 mg/kg substrate) > MSS (403 mg/kg substrate). The specific gravity of eight substrate materials (except gravel) had very significant negative correlations with the P sorption, whereas the particle diameter of D60 and uniformity coefficient (K60) had positive correlations with the P sorption. The cation exchange capacity, organic matter, available ferrous, and exchangeable aluminum of the eight substrate materials also had very significant positive correlations with the P sorption, while the pH of the substrate materials showed a very significant negative correlation with the P sorption. Our study further suggests that turf and CBAS are the two relatively ideal substrate materials suitable for removal of P from a CW system.
Trace Metals in Sediments and Zostera marina of San Ignacio and Ojo de Liebre Lagoons in the Central Pacific Coast of Baja California, Mexico by J. V. Macías-Zamora; J. L. Sánchez-Osorio; L. M. Ríos-Mendoza; N. Ramírez-Álvarez; M. A. Huerta-Díaz; D. López-Sánchez (pp. 218-228).
San Ignacio and Ojo de Liebre lagoons in central Baja California, Mexico are nursery and grazing grounds for whales and turtles. Ojo de Liebre Lagoon also supports a salt mine operation. By concentrating trace metals via evaporation, this activity might harm biota. Consequently, salt mining might be incompatible with the lagoon’s ecological role. Eelgrass can incorporate these elements and reroute them to other organisms. Trace metals in sediments (Cd, Co, Cu, Mn, Ni, Pb, Zn, and Fe) were measured at both lagoons. Some (Cu, Mn, Pb, and Zn) were also measured in Zostera marina patches at both lagoons. The results did not show elevated metal concentration at any lagoon, either for sediments or eelgrass. No statistically significant differences between lagoons were found. However, eelgrass at both lagoons showed larger concentration ranges than in sediments. Also, a correlation exists between sediment metal concentration and its concentration in eelgrass. Surprisingly, several sediment metal concentrations are higher than those considered as elevated for the Southern California Bight.
Availability of Ferrocyanide and Ferricyanide Complexes as a Nitrogen Source to Cyanogenic Plants by Xiao-Zhang Yu; Ji-Dong Gu; Tian-Peng Li (pp. 229-237).
The effects of additional nitrogen on the toxicity and removal of ferrocyanide and ferricyanide by cyanogenic plants were investigated. Maize (Zea mays L. var. ZN 304) seedlings were grown in the hydroponic solutions with or without additional nitrogen, and amended with either potassium ferrocyanide or potassium ferricyanide at 25.0 ± 0.5°C for 144 h. Various physiological parameters were monitored to determine the responses of the plant seedlings to the exposure of these two chemicals. A remarkable decrease in transpiration rate, biomass, shoot length, chlorophyll contents, and soluble proteins was evident for maize seedlings grown in the N-free hydroponic solutions spiked with either ferrocyanide or ferricyanide (P < 0.01), but slight changes were observed in the selective parameters in the N-containing hydroponic solutions spiked with either of these chemicals (P > 0.05). A higher removal of ferrocyanide than ferricyanide was registered in the N-free hydroponic solutions, but more ferricyanide than ferrocyanide was removed by maize grown in the N-containing nutrient solutions (P < 0.01). Although roots of maize accumulated iron cyanides, more cyanide was recovered in plant materials of those grown in the N-containing hydroponic solutions than the N-free nutrient solutions (P < 0.05). Mass balance analysis indicated that the majority of the iron cyanides removed from solution was assimilated by maize and additional nitrogen had a significantly negative impact on the uptake of both chemicals (P < 0.01). Results of this study suggest that uptake and assimilation mechanisms for ferrocyanide and ferricyanide might be quite different in maize and the application of the external nitrogen has a substantial influence on the removal of both iron cyanides by plants. None of the iron cyanide complexes can serve as a sole nitrogen source to support maize growth.
Copper Accumulation and Tolerance in Chrysanthemum coronarium L. and Sorghum sudanense L. by Lan Wei; Chunling Luo; Xiangdong Li; Zhenguo Shen (pp. 238-246).
In the present study, the growth of Chrysanthemum coronarium L. and Sorghum sudanense L. and their copper accumulation were studied using hydroponic experiments. Results showed that the root elongation, dry biomass yield, and chlorophyll content in both plant species decreased significantly with the increasing level of Cu in solution. The concentrations of Cu in the two plants increased greatly with the increasing Cu level in the treatments. However, most of the Cu was accumulated in roots, and only a small portion was translocated into shoots. Compared with S. sudanense, the shoots of C. coronarium had a significantly higher concentration of Cu. The total amount and percentage of water-soluble Cu, and the nonprotein thiol were also higher in the shoots of C. coronarium. In the roots, however, S. sudanense accumulated more Cu than C. coronarium. The treatments with 5 to 50 μmol L−1 Cu significantly increased the uronic acid content in the roots of S. sudanens, but did not have any significant effect for C. coronarium. Higher concentrations of Cu bound to the cell wall and uronic acid in the roots of S. sudanense were speculated to be the main reason to restrain Cu translocation from roots to shoots.
Potential of 11 Pesticides to Initiate Downstream Drift of Stream Macroinvertebrates by Mikhail A. Beketov; Matthias Liess (pp. 247-253).
Downstream drift of lotic macroinvertebrates induced by toxicants is a well-known ecologically relevant phenomenon. However, little is known about which toxicants can initiate drift, and potential drift-initiating effects of contaminants are not taken into account in ecotoxicological risk assessment. The aim of the present study was to evaluate potential drift-initiating action of 11 pesticides having different target groups and modes of action. Sublethal concentrations of the pesticides were tested in stream microcosms with amphipods (Gammarus pulex), blackfly larvae (Simulium latigonium), and mayfly larvae (Baetis rhodani). The results show that 6 out of 11 pesticides tested can initiate drift of macroinvertebrates at sublethal concentrations 7–22 times lower than acute LC50s (thiacloprid, imidacloprid, acetamiprid, iprodione, fenvalerate, and indoxacarb). All the toxicants that exhibited drift-initiating action are neurotoxic insecticides belonging to the groups of pyrethroids and neonicotinoids except the fungicide iprodione. The pesticides that did not initiate drift are fungicides (cyprodinil, prochloraz, and azoxystrobin), a juvenile-hormone mimic (fenoxycarb), and a pyrazole insecticide (tebufenpyrad) affecting cell energy production. Remarkably, for all the drift-initiating toxicants, drift of the tested animals was detected within 2 h after contamination. This shows that macroinvertebrate drift can be induced even by short-term pulse exposures to neurotoxic insecticides, at field-relevant concentrations. The present results imply that the possibility of drift-initiating effects of pesticides should be considered within the risk assessment framework for pesticides, as all neurotoxic substances that were investigated did initiate drift at sublethal concentrations.
Morphological and Functional Changes in the Thyroid Gland of Methyl Thiophanate-Injected Lizards, Podarcis sicula by Rosaria Sciarrillo; Maria De Falco; Francesca Virgilio; Vincenza Laforgia; Anna Capaldo; Flaminia Gay; Salvatore Valiante; Lorenzo Varano (pp. 254-261).
The thyroid has been shown to be a target organ for environmental chemicals, specifically endocrine-disrupting contaminants. Reptiles are particularly suitable as contaminant biomonitors due to their persistence in a variety of habitats, wide geographic distribution, longevity, and, in many cases, site fidelity. Methyl thiophanate is a systemic broad-spectrum fungicide used to prevent and control plant diseases caused by various fungi. The aim of this study was to develop an integrated biological model for monitoring the ecotoxic effects of thiophanate-methyl fungicide on the thyroid of the lizard Podarcis sicula. The results of this study indicate that both structural and functional differences in the thyroid gland of the lizard exist in the animals exposed to methyl thiophanate. Structurally, animals exposed to methyl thiophanate showed decreased epithelial cell height; the nuclei of the thyroid cells were small and elongated with dense chromatin and a greatly reduced cytoplasm. The colloid was retracted with few reabsorption vacuoles. Functionally, the same animals exhibited decreased T4 and T3 plasma levels compared to control animals. Methyl thiophanate administration produced statistically significant inhibition on serum thyroid-stimulating hormone levels and this is the mechanism for altering thyroid function. This study highlights how thyroid gland disruption, both structural and functional, in lizard and other nontarget organisms might also have an environmental aetiology.
Oxidative Stress Response in Gill and Liver of Liza saliens, from the Esmoriz-Paramos Coastal Lagoon, Portugal by C. Fernandes; A. Fontaínhas-Fernandes; M. Ferreira; M. A. Salgado (pp. 262-269).
Tissue-specific responses against oxidative stress and lipid peroxidation were analyzed in wild adult mullet (Liza saliens) caught in the Portuguese coastal lagoon Esmoriz-Paramos. Parameters measured were catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) activities in liver and gill tissues and lipid peroxidation. The enzyme activities were related to gill histopathological alterations, as well as to heavy metals (Cu and Zn) concentrations in these tissues. Gill epithelium of L. saliens showed histological alterations, such as epithelial hyperplasia resulting in lamellar fusion, epithelial lifting, vasodilatation, and lamellar aneurisms, with a prevalence ranging from 62% to 92%. The highest Cu content was found in liver (379 mg·kg−1), while the highest Zn content was observed in gill (119 mg·kg−1). SOD and CAT activities showed differences between gill and liver. The highest activities found were SOD in gill (10.1 U/mg protein) and CAT in liver (39.2 mmol/min/mg protein). In gill, CAT activity was negatively related to both Cu levels and gill lifting, while a positive relationship was found between SOD activity and fish age. The positive relationship between Cu and CAT activity in liver suggests that an increase in metabolic level is related to Cu-induced oxidative stress. The decrease in gill CAT activity can be due to osmotic stress caused by damaged gill epithelium. CAT activity in liver is an appropriate biomarker of oxidative stress in the Esmoriz-Paramos lagoon.
Contaminant Concentrations and Histopathological Effects in Sacramento Splittail (Pogonichthys macrolepidotus) by Ben K. Greenfield; Swee J. Teh; John R. M. Ross; Jennifer Hunt; GuoHua Zhang; Jay A. Davis; Gary Ichikawa; David Crane; Silas S. O. Hung; DongFang Deng; Foo-Ching Teh; Peter G. Green (pp. 270-281).
Sacramento splittail (Pogonichthys macrolepidotus) is a species of special concern in California, due to multiple anthropogenic stressors. To better understand the potential impact of contaminant exposure, adult splittail were captured from the Sacramento-San Joaquin River Delta (California, USA) and analyzed for histopathology and contaminant exposure. Organochlorine contaminants (PCBs, DDTs, dieldrin, chlordanes, and PBDEs) and trace metals (Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sn, V, and Zn) were detected in the tissues of all fish. In many samples, human health screening values were exceeded for PCBs (83 of 90 samples), DDTs (32 samples), and dieldrin (37 samples). In contrast, thresholds for fish effects were rarely exceeded. Histopathological analysis indicated the presence of macrophage aggregates in gonads, kidneys, and liver and a high incidence of liver abnormalities. In the liver, observed effects were often moderate to severe for glycogen depletion (55 of 95 fish), lipidosis (hepatocellular vacuolation; 51 fish), and cytoplasmic inclusion bodies (33 fish). Correlations between histopathology and tissue contaminant concentrations were weak and inconsistent. Significant correlations were observed between histopathology indicators and reductions in fish size, body condition, lipid content, and liver weight. These results suggest that splittail histopathology varies as a function of health and nutritional status, rather than exposure to legacy organic and metal pollutants.
Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs) in 0+ Juvenile Cyprinids and Sediments of the Po River by Luigi Viganò; Claudio Roscioli; Claudio Erratico; Licia Guzzella (pp. 282-294).
PBDE and PCB content has been determined in 0+ bleak (Cyprinus alburnus), nase (Chondrostoma soetta), gudgeon (Cyprinus gobio), chub (Cyprinus cephalus), and barbel (Barbus sp.) as well as in bed sediments sampled from the River Po upstream and downstream of the confluence of a tributary draining a highly industrialized and urbanized subbasin. Both groups of chemicals were present at higher levels in fish and sediments downstream from the confluence. In addition, whole-body concentrations of PBDEs and PCBs were different among species despite the young specimen age. The fact that PBDEs and PCBs were higher in benthivorous versus planktivorous fish, as well as in carnivorous versus herbivorous species, suggests that feeding behavior is a major controlling factor that may help differentiate the accumulation levels of 0+ juveniles. Of the five species, the pelagic/planktivorous cyprinid bleak (C. alburnus) showed the lowest concentrations (111 ng PBDE/g lipid weight [l.w.], 2016 ng PCB/g l.w.), whereas the benthic dweller and feeder barbel (Barbus sp.) had the highest concentrations of both groups of chemicals (259 ng PBDE/g l.w., 4785 ng PCB/g l.w.). The rank order of species contamination was essentially stable upstream and downstream from the tributary, and the congener contribution of PBDEs was also similar. In general, BDE-47 was the dominant congener, followed by BDE-100, -154, -153, and -28. BDE-209 dominated the PBDE congener profiles of sediments but was not found in any fish sample. Conversely, an unidentified hexa-BDE congener, which was not detected in sediments, was found in all fish species. The levels of PBDEs and PCBs determined in adult goby (Padogobius martensii), a small demersal predator also examined in the same river stretches, provided additional useful insights with which to interpret results.
Assessment of Water Pollution in the Tronto River (Italy) by Applying Useful Biomarkers in the Fish Model Carassius auratus by F. A. Palermo; G. Mosconi; M. Angeletti; A. M. Polzonetti-Magni (pp. 295-304).
The Tronto River (southern Marche region of central Italy) is located in an area with neighboring industrial activities and is contaminated with domestic and industrial wastewater. Water quality data analyses revealed the presence of a mixture of low levels of heavy metals and organic compounds. The effects of long-term exposure to Tronto River water on juvenile Carassius auratus were evaluated with an integrated approach using xenoestrogens biomarkers, such as vitellogenin (VTG) and ER β-1 mRNA expression, and stress parameters (i.e., cortisol and glucose in the blood and glycogen in the liver). Treatment with Tronto River water did not induce VTG synthesis in fish and did not affect ER β-1 mRNA expression. Moreover, cortisol titers found in the plasma of fish exposed to Tronto River water were lower than those found in the control group. Regarding energy parameters, treatment with Tronto River water induced an increase in plasma glucose and a depletion of liver glycogen reserves.The effects of Tronto River water were studied in parallel with those of 4-NP and CdCl2. The 4-NP at the dose of 22 μg/L induced the synthesis of peripheral vitellogenin and increase of ER β-1 titers; on the contrary, CdCl2 exposure at the concentration of 22 μg/L did not induce significant changes on plasma VTG and/or hepatic ER β-1 levels. In addition, no significant changes in plasma cortisol levels in fish exposed to 4-NP or CdCl2 were found. Fish exposed to CdCl2 displayed liver glycogen depletion, but no significant increase in plasma glucose was observed. On the contrary, a 30-day exposure to 4-NP induced only a slight decrease of glycogen reserves without any changes in plasma glucose levels.In conclusion, our study demonstrated that long-term exposure of juvenile goldfish to the water of the Tronto River significantly affects both stress and energy parameters. There is evidence that pollutants, present in Tronto River water, were not able to induce xenoestrogenic effects but caused a functional impairment of the hypothalamum–pituitary–interrenal axis.
Distribution of Mercury in Several Environmental Compartments in an Aquatic Ecosystem Impacted by Gold Mining in Northern Colombia by Jose Marrugo-Negrete; Luis Norberto Benitez; Jesús Olivero-Verbel (pp. 305-316).
Mercury (Hg) used in gold amalgamation is a major source of contamination in developing countries. Water, sediments, plankton, fish, and human samples from Grande Marsh, a Hg-polluted marsh located in the south of Bolívar, municipality of Montecristo, Colombia, were collected during both the rainy and the dry seasons (2003–2006), at three different sampling sites, and analyzed for total Hg (T-Hg) content. Water, sediment, seston, phytoplankton, and zooplankton T-Hg concentrations were 0.33 ± 0.03 μg/L, 0.71 ± 0.03, 1.20 ± 0.06, 0.52 ± 0.03, and 0.94 ± 0.05 μg/g dry weight (wt), respectively. T-Hg levels in these compartments were highly pair-correlated (p < 0.05), and for all of them, except sediments, greater values were found during the dry season. Significant differences were observed for T-Hg concentrations in fish according to their trophic position. Average highest T-Hg values were found in carnivorous species such as Caquetaia kraussi (1.09 ± 0.17 μg/g fresh wt), Hoplias malabaricus (0.58 ± 0.05 μg/g fresh wt), and Plagioscion surinamensis (0.53 ± 0.07 μg/g fresh wt), whereas the lowest were detected in noncarnivorous species such as Prochilodus magdalenae (0.157 ± 0.01 μg/g fresh wt). In those fish species where seasonal comparisons were possible, specimens captured during the dry season had greater T-Hg levels in muscle. Although the T-Hg mean level for all fish samples (0.407 ± 0.360 μg/g fresh wt) did not exceed the recommended limit ingestion level, risk assessment based on the hazard index suggested that a fish intake of 0.12 kg per day (a small carnivorous specimen) could increase the potential health effects related to Hg exposure in the local human population, whose hair T-Hg median value was 4.7 μg/g, and presented a low but significant correlation with fish consumption (r = 0.250, p = 0.016). In short, Hg pollution from gold mining around Grande Marsh has permeated the food web, and currently levels in fish represent a serious concern for human health.
The Influence of Diet on Mercury Intake by Little Tern Chicks by Vitor H. Paiva; Paula C. Tavares; Jaime A. Ramos; Eduarda Pereira; Sandra Antunes; Armando C. Duarte (pp. 317-328).
We assessed mercury levels in the feathers of little tern (Sternula albifrons) chicks from hatching to fledging and in their prey captured by adults in three main foraging habitats: lagoon, salinas, and adjacent sea. These data were used to model mercury concentration in chick feathers through food ingestion, in order to explore the effects that changes in diet would have on the mercury burden of chicks as they aged. The mercury concentration in feathers of chicks raised in sandy beaches was higher than in those raised in salinas. Lagoon prey had a significantly higher mercury concentration (0.18 ± 0.09 μg g−1 dry weight [d.w.]) than prey from salinas and the adjacent sea (both 0.06 ± 0.03 μg g−1 d.w.). In relation to prey species group, mercury content was significantly higher for bottom fish (0.17 ± 0.10 μg g−1 d.w.) than for pelagic (0.08 ± 0.06 μg g−1 d.w.), euryhaline fish (0.04 ± 0.02 μg g−1 d.w.), and crustacea (0.08 ± 0.03 μg g−1 d.w.). To understand the importance of mercury content of each prey group, we ran several theoretical scenarios assuming that chicks were fed on only one species at a time. Considering a diet restricted to lagoon (mostly benthic) prey, A- and B-chicks may encounter health problems with an excess of mercury. On the contrary, a diet restricted to marine (mostly pelagic) prey would decrease the mercury concentration in chick feathers; the fast growth rate and the related mercury dilution effect in little tern chicks seem to decrease mercury levels in their feathers. Our study supports the fact that marine pelagic prey are important for estuarine seabirds because they provide a food resource with lower contamination levels. This model may have a wider application in similar seabird species and coastal environments.
Reference Values of Urinary Trans,trans-muconic Acid: Italian Multicentric Study by C. Aprea; G. Sciarra; N. Bozzi; M. Pagliantini; A. Perico; P. Bavazzano; A. Leandri; M. Carrieri; M. L. Scapellato; M. Bettinelli; G. B. Bartolucci (pp. 329-340).
This article reports the results of a study, conducted in the framework of the scientific activities of the Italian Society for Reference Values, aimed at defining reference values of urinary trans,trans-muconic acid (t,t-MA) in the general population not occupationally exposed to benzene. t,t-MA concentrations detected in 376 subjects of the resident population in three areas of Italy, two in central (Florence and southern Tuscany) and one in northern Italy (Padua), by three laboratories, compared by repeated interlaboratory controls, showed an interval of 14.4–225.0 μg/L (5th–95th percentile) and a geometric mean of 52.5 μg/L. The concentrations measured were influenced by tobacco smoking in a statistically significant way: Geometric mean concentrations were 44.8 μg/L and 76.1 μg/Ll in nonsmokers (264 subjects) and smokers (112 subjects), respectively. In the nonsmoking population, a significant influence of gender was found when concentrations were corrected for urinary creatinine, geometric mean concentrations being 36.7 μg/g creatinine in males (128 subjects) and 44.7 μg/g creatinine in females (136 subjects). The place of residence of subjects did not seem to influence urinary excretion of the metabolite, although personal inhalation exposure to benzene over a 24-h period showed slightly higher concentrations in Padua and Florence (geometric means of 6.5 μg/m3 and 6.6 μg/m3, respectively) than in southern Tuscany (geometric mean of 3.9 μg/m3). Concentration of t,t-MA in urine samples collected at the end of personal air sampling showed little relationship to personal inhalation exposure to benzene, confirming the importance of other factors in determining excretion of t,t-MA when concentrations in personal air samples are very low.