Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Archives of Environmental Contamination and Toxicology (v.46, #3)
Isotope Dilution High-Performance Liquid Chromatography–Tandem Mass Spectrometry Method for Quantifying Urinary Metabolites of Synthetic Pyrethroid Insecticides by Samuel E. Baker; Anders O. Olsson; Dana B. Barr (pp. 281-288).
This paper describes a method for measuring cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acids (cis-DCCA and trans-DCCA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (DBCA), 3-phenoxybenzoic acid (3PBA), and 4-fluoro-3-phenoxybenzoic acid (4F3PBA) in human urine. These compounds are considered to be reliable biomarkers of exposure for many pyrethroid insecticides used in the United States. In this method, stable isotopically labeled analogues of trans-DCCA and 3PBA were spiked into urine as internal standards. After solid-phase extraction, the extracts were analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry using turbo ion-spray atmospheric pressure ionization. The limits of detection (LODs) ranged from 0.1 to 0.5 μg/L. Within-day relative standard deviations ranged from 1.8 to 13% and between-day relative standard deviations ranged from 0.5 to 18%. Absolute analyte recoveries ranged from 72 to 93%. Chromatographic retention times were less than 8 min. This method was used to measure urinary concentrations of these metabolites in persons with no known exposure to pyrethroids and some with suspected residential exposure. Metabolites of synthetic pyrethroids were detected in 74% of the samples analyzed. cis-DCCA, trans-DCCA, DBCA, 4F3PBA, and 3PBA were detected in 36, 50, 3, 9, and 64% of the samples analyzed, respectively.
A Procedure to Purify and Culture a Clonal Strain of the Aquatic Moss Fontinalis antipyretica for Use as a Bioindicator of Heavy Metals by C. Rausch de Traubenberg; C. Ah-Peng (pp. 289-295).
A procedure to culture the aquatic moss, Fontinalis antipyretica, is described. The moss was collected in a stream, carried to the laboratory, and immediately treated: apices were isolated and rinsed under a stereomicroscope and submitted to ultrasonic cleaning combined with an iodine treatment and then to an antibiotic/anti-eukaryotic treatment for 4 days. This procedure permitted us for the first time to eliminate the microalgae associated with an aquatic moss in culture, solving the problem of proliferation of these microalgae in the culture medium. Furthermore, the minimal concentration of eight essential metals required by this moss was determined in order to have metal concentrations in the cultured moss as low as possible. A perennial culture of a clonal strain of an aquatic moss for use as a metal bioaccumulator was obtained and the first step to provide a standardized bioindication tool for metal detection in continental waters was passed over.
Atrazine Induces Homologous Recombination But Not Point Mutation in the Transgenic Plant-Based Biomonitoring Assay by Jill Besplug; Jody Filkowski; Paula Burke; Igor Kovalchuk; Olga Kovalchuk (pp. 296-300).
Herbicides, such as atrazine, are extensively used in agriculture in order to suppress growth of weeds. From the soil they inevitably find their way to water supplies, leading to human exposure via drinking water. Therefore, it is extremely important to know whether those chemicals pose any hazard to public health. The genotoxicity of atrazine has been a subject of studies in recent years. However, the data that are currently available are inconclusive. There is a need to examine the genotoxicity of low, environmentally relevant concentrations that are currently assumed to be safe. Up to date, studying the genotoxicity of low concentrations of atrazine has constituted a great challenge due to the lack of appropriate, sensitive test systems. In the present work, we used a new sensitive transgenic plant-based system to study the genotoxicity and mutagenicity of atrazine present at minute concentrations in the liquid media. This system gave us an opportunity to monitor the two main types of rearrangements, the frequency of homologous recombination and point mutations, which are indicators of the genotoxicity of atrazine. Atrazine present at low concentrations was found to be a strong inducer of homologous recombination. On the other hand, it did not have a significant influence on the levels of A → G and T → G mutations. These results suggest that the transgenic plantbased biomonitoring system is a useful tool for analyzing the genotoxicity of water contaminated by atrazine. In the future this system can be used to study molecular mechanisms of genotoxicity and mutagenicity atrazine and other triazine herbicides.
Atrazine-Induced Chlorosis in Synechococcus elongatus Cells by Óscar González-Barreiro; Carmen Rioboo; Angeles Cid; Concepción Herrero (pp. 301-307).
The effects of a widely used herbicide, atrazine, on the freshwater cyanobacterium Synechococcus elongatus were studied. The cyanobacteria were exposed to varying concentrations of atrazine (0.025, 0.05, 0.1, 0.25, and 0.75 μM) for 96 h. Different parameters such as growth, autofluorescence of chlorophyll a, pigment content, volume, and internal granularity of the cells were determined daily. Differences were detected between cultures with and cultures without atrazine for the parameters analyzed. Atrazine exposure induced the process of chlorosis in cyanobacterial cells, given that this herbicide has an effect on photosynthesis, chlorotic subpopulations having low values of chlorophyll a autofluorescence. More unpigmented subpopulations (chlorotic) appeared as the atrazine concentration increased and better growth rates resulted. Atrazine also induced changes in cell volume and internal granularity, these being most apparent after 48 h of exposure and in cultures with higher atrazine concentrations (0.25 and 0.75 μM).
Toxicity of Atrazine and Molinate to the Cladoceran Daphnia carinata and the Effect of River Water and Bottom Sediment on Their Bioavailability by Yin Latt Phyu; M. St. J. Warne; R. P. Lim (pp. 308-315).
Atrazine and molinate are widely used herbicides and concern has been raised about their potential deleterious impacts on aquatic ecosystems. Although there have been some studies on the toxicity of herbicides to aquatic organisms using laboratory or natural water, information on the effect of sediments, suspended particulates, and dissolved organic matter on their bioavailability is quite limited. This study aims to provide toxicity data that considers these factors and the effect that these factors have on bioavailability. In this study, the toxicity of the test chemicals was calculated following the Organisation for Economic Co-operation and Development (OECD) methods, whereas change in bioavailability was measured using EC50 values based on measured initial concentrations of the test chemicals. The acute (48-h) static toxicity of atrazine and molinate to the freshwater cladoceran Daphnia carinata was determined in cladoceran water and river water in the absence and presence of sediment. The 48-h EC50 (immobilization) values of atrazine to D. carinata ranged from 22.4 to 26.7 mg/L, while the corresponding values for molinate ranged from 18.3 to 33.6 mg/L, respectively. Both chemicals were classed as having low acute toxicity to D. carinata. The presence of dissolved organic matter and suspended particles in river water did not significantly (p > 0.05) reduce the bioavailability (measured as toxicity) of atrazine to D. carinata compared to that tested in cladoceran water. The presence of sediment, however, signifi- cantly (p < 0.05) reduced the bioavailability (48-h EC50) of atrazine in cladoceran water, from 24.6 to 30.7 mg/L, and in river water, from 22.4 to 31.0 mg/L. Similarly, the presence of sediment in cladoceran water, significantly (p < 0.05) reduced the bioavailability (48-h EC50) of molinate, from 26.6 to 46.4 mg/L, and in river water, from 22.5 to 45.6 mg/L.
Comparative Toxicity of Glyphosate-Based Herbicides: Aqueous and Sediment Porewater Exposures by Martin T. K. Tsui; L. M. Chu (pp. 316-323).
Glyphosate-based herbicides are widely used for aquatic weed control. However, their aquatic toxicity data, especially those on sediment, are relatively scarce. In this study, the water-only acute toxicity of three formulations based on glyphosate (Rodeo, Roundup Biactive, and Roundup) were compared using a water-column organism (cladoceran: Ceriodaphnia dubia) and a benthic organism (amphipod: Hyalella azteca). In addition, Roundup Biactive and Roundup were spiked into a clean sediment which was amended with appropriate amounts of peat moss to study the effect of different organic carbon levels (0, 0.4, 1.2, and 2.1%) on their sediment toxicity, with C. dubia exposed to overlying water or porewater prepared from the contaminated sediments. Results showed that the toxicity based on 48-h LC50s for the three herbicides in the water-only tests was Roundup (1.5–5.7 mg L-1) > Roundup Biactive (82–120 mg L-1) > Rodeo (225–415 mg L-1), and H. azteca was generally more sensitive than C. dubia to these herbicides. Toxicity differences between formulations were due to the different surfactant components in these herbicides. From the porewater toxicity tests, Roundup Biactive (340 mg kg-1) and Roundup (244 mg kg-1) were similarly toxic in the sediment tests at 0% organic carbon, indicating that the surfactants in Roundup were considerably more adsorptive than those in Roundup Biactive to the sediment of the same organic carbon. Also, an increase in organic carbon significantly decreased the toxicity of Roundup in sediment, but not for Roundup Biactive. Sediment–porewater partitioning of glyphosate was found to be influenced by sediment organic carbon (i.e., glyphosate adsorption increased with sediment organic carbon).
Comparison of Laboratory Single Species and Field Population-Level Effects of the Pyrethroid Insecticide λ-Cyhalothrin on Freshwater Invertebrates by A. F. W. Schroer; J. D. M. Belgers; C. M. Brock; A. M. Matser; S. J. Maund; P. J. Van den Brink (pp. 324-335).
The toxicity of the pyrethroid insecticide λ-cyhalothrin to freshwater invertebrates has been investigated using data from short-term laboratory toxicity tests and in situ bioassays and population-level effects in field microcosms. In laboratory tests, patterns of toxicity were consistent with previous data on pyrethroids. The midge Chaoborus obscuripes was most sensitive (48- and 96-h EC50 = 2.8 ng/L). Other insect larvae (Hemiptera, Ephemeroptera) and macrocrustacea (Amphipoda, Isopoda) were also relatively sensitive, with 48- and 96-h EC50 values between 10 and 100 ng/L. Generally, microcrustacea (Cladocera, Copepoda) and larvae of certain insect groups (Odonata and Chironomidae) were less sensitive, with 48-h EC50 values higher than 100 ng/L. Mollusca and Plathelminthes were insensitive and were unaffected at concentrations at and above the water solubility (5 μg/L). Generally, the EC50 values based on initial population responses in field enclosures were similar to values derived from laboratory tests with the same taxa. Also, the corresponding fifth and tenth percentile hazard concentrations (HC5 and HC10) were similar (laboratory HC5 = 2.7 ng/L and field HC5 = 4.1 ng/L; laboratory and field HC10 = 5.1 ng/L), at least when based on the same sensitive taxonomic groups (insects and crustaceans) and when a similar concentration range was taken into account. In the three field enclosure experiments and at a treatment level of 10 ng/L, consistent effects were observed for only one population (Chaoborus obscuripes), with recovery taking place within 3 to 6 weeks. The laboratory HC5 (2.7 ng/L) and HC10 (5.1 ng/L) based on acute EC50 values of all aquatic arthropod taxa were both lower than this 10 ng/L, a concentration that might represent the “regulatory acceptable concentration.” The HC5 and HC10 values in this study in The Netherlands (based on static laboratory tests with freshwater arthropods) were very similar to those derived from a previous study in the United Kingdom (1.4 and 3.3 ng/L). This suggests that for pesticides like λ-cyhalothrin, HC5 values based on static laboratory tests may provide a conservative estimate of the potential for community-level effects under field conditions. While these HC5 values are conservative for initial effects, they do not provide information on recovery potential, which may be important for regulatory decision-making.
Hormetic Versus Toxic Effects of Vegetable Tannin in a Multitest Study by E. De Nicola; M. Gallo; M. Iaccarino; S. Meric; R. Oral; T. Russo; T. Sorrentino; O. Tünay; E. Vuttariello; M. Warnau; G. Pagano (pp. 336-344).
Tannin from mimosa trees (Acacia sp.) utilized in traditional leather tanning was tested for toxicity in sea urchin (Sphaerechinus granularis and Paracentrotus lividus) embryos and sperm, marine, and freshwater algae (Selenastrum capricornutum and Dunaliella tertiolecta), and Daphnia magna. Based on a two-step tanning procedure used in traditional tanneries, two mimosa tannin preparations, i.e., fresh tannin (FT) and used tannin (UT), were tested as suspensions. The early results in S. granularis embryos showed that UT exerted lower acute toxicity than FT, namely, 1 vs 100 mg/L, to obtain 100% mortality, respectively. Subsequent bioassays were conducted on fresh tannin water extracts (TWE) corresponding to nominal tannin concentrations ranging from 0.1 to 30 mg/L. Developmental toxicity, up to embryonic mortality was exerted by TWE at levels >1 mg/L, S. granularis being more sensitive than P. lividus embryos/larvae. At the concentration of 0.1 mg/L, the frequencies of larval malformations were significantly lower than in controls. This positive stimulatory effect (currently termed as hormesis) was observed in extended numbers of culture replicates (up to 14) and was significant in the embryo cultures characterized by a relatively poor control quality (with <70% viable larvae in controls), whereas this effect was not observed in good-quality cultures (with ≥70% viable larvae in controls). Cytogenetic analysis of S. granularis embryos reared in FT or UT suspensions (1 mg/L to 1 g/L) showed mitotoxic effects (decrease in active mitoses per embryo) in FT-exposed, but not in UT-exposed embryos. Mitotic aberrations were significantly increased by 10 mg/L UT. Sperm fertilization success in both sea urchin species showed an increasing fertilization rate (FR) up to 0.3 mg/L TWE and a dose-related decrease in FR up to 30 mg/L. Again, the offspring of P. lividus sperm exposed to TWE (0.1 and 0.3 mg/L) showed a decrease in larval malformations compared to controls, whereas a dose-related increase in developmental defects was observed in the offspring of P. lividus sperm exposed to higher TWE levels (1 to 30 mg/L). Algal cell growth bioassays in two species (S. capricornutum and D. tertiolecta) also showed a maximum growth at TWE levels ranging from 0.3 to 3 mg/L and a subsequent decline up to 30 mg/L TWE. D. magna bioassays resulted in daphnid immobilization by TWE concentrations ranging from 100 to 300 mg/L. The results demonstrate that tannins utilized in traditional leather tanning industry may raise concern of environmental damage at relatively high concentrations, whereas low-level tannins may result in hormetic effects. The present study also points to the need for bioassay design that should rely on adequate criteria in control quality, allowing to detect both inhibitory and hormetic effects.
Runoff-Related Endosulfan Contamination and Aquatic Macroinvertebrate Response in Rural Basins Near Buenos Aires, Argentina by S. Jergentz; H. Mugni; C. Bonetto; R. Schulz (pp. 345-352).
Information in the open literature about the fate and effects of pesticides in small streams from agricultural areas of Argentina is very rare. The objective of the present work was to study the pesticide contamination and potential biological effects in basins that have undergone intense agricultural activity, mainly related to the cultivation of soybeans. Three streams (Maguire, Helves, and Horqueta) with a low-flow discharge (0.1 and 0.2 m3/s) in March close to the city of Arrecifes were studied during the period of maximum insecticide application, between February and April 2001. Various sampling devices were installed to trap suspended particles, runoff, and floodwater plus sediment throughout the study period. The suspended-particle samples were analyzed for the insecticides endosulfan (END), chlorpyrifos, and cypermethrin. Water chemistry and the macroinvertebrate communities were assessed on four occasions and the organismic drift was measured continuously. Following a 184-mm rainfall on March 1, 2001, β-endosulfan concentrations up to 318 and 43 µg/kg were measured from suspended-particle samples from Horqueta and Helves, respectively. No END contamination was detected in Maguire. Chlorpyrifos and cypermethrin were not detected in any of the streams. A significant decrease in the average macroinvertebrate species density was observed in Horqueta (from 12.8 ± 0.5 to 9 ± 0.7 species; ANOVA, p < 0.05) and Helves (from 10.8 ± 1.7 to 3.3 ± 1.3 species; p < 0.001) following the same rainfall event at the beginning of March, while the species density in Maguire remained constant at 7.9 ± 0.3 species. The runoff primarily reduced species abundances of Odonata and Ephemeroptera significantly (p < 0.01) in Horqueta and Helves but not in Maguire. A greater drift of Smicridae (Trichoptera) and Ephemeroptera occurred in Helves and Horqueta during this runoff event, while no changes in the macroinvertebrate drift were detectable in Maguire. This study highlights the potential pesticide effects on macroinvertebrate communities in Argentinian rural streams. It is suggested that a small wetland area formed by Maguire between the agriculturally used catchment and the sampling site contributes to the absence of contamination and effects at this site.
Trace Metal Concentrations and Susceptibility to Oxidative Stress in the Polychaete Sabella spallanzanii (Gmelin) (Sabellidae): Potential Role of Antioxidants in Revealing Stressful Environmental Conditions in the Mediterranean by R. Bocchetti; D. Fattorini; M. C. Gambi; F. Regoli (pp. 353-361).
The polychaete Sabella spallanzanii (Gmelin) (Sabellidae) is a widely distributed species throughout the Mediterranean where it is commonly found in sheltered shallow areas and up to 30 m depth in more exposed waters. The sedentary habit, the filter-feeding behavior and its capability to colonize disturbed environments such as harbors, suggest the potential utility of this organism as a bioindicator in environmental monitoring programs. The aim of this work was a preliminary characterization of S. spallanzanii, integrating chemical data on trace metal concentrations with the biochemical analysis of antioxidant defenses which play an important role in mediating responses and adaptation to stressful environmental conditions. Organisms were collected in four locations of the Adriatic and Tyrrhenian Sea, characterized by a moderate impact or influenced by organic enrichment or sulphuric emissions. Trace metal concentrations (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were comparable to those of other invertebrate species and quite typical for unpolluted environments. Analyses of individual antioxidants (superoxide dismutase, catalase, glutathione peroxidases, glutathione S-transferases, glutathione reductase) were integrated with measurement of the total oxyradical scavenging capacity toward specific forms of ROS; the TOSC assay, quantifying the overall capability of a tissue to neutralize specific reactive oxygen species provide a more integrated picture of the balance between prooxidant factors and antioxidant defenses, with important indications about the role of different ROS in appearance of oxidative disease. The antioxidant profile was influenced by the different physiological functions of the analyzed tissues, namely the branchial crown, involved in filtration of large volumes of seawater, and the thorax where digestive processes occur. The analysis of antioxidant defenses revealed significant variations in polychaetes from various sampling sites suggesting the influence of specific environmental conditions like those limiting oxygen availability. Our results confirm the role of antioxidants in adaptation to stressful environmental conditions and their importance in ecotoxicological studies for the sensitivity in revealing the occurrence of biological disturbance.
Evaluation of Lethality and Genotoxicity in the Freshwater Mussel Utterbackia imbecillis (Bivalvia: Unionidae) Exposed Singly and in Combination to Chemicals Used in Lawn Care by Deanna E. Conners; Marsha C. Black (pp. 362-371).
Many chemicals, including fertilizers, herbicides, and insecticides, are routinely applied to turf in the care and maintenance of lawns. These chemicals have the potential to leach into nearby surface waters and adversely affect aquatic biota. In this study, we evaluated the lethal and genotoxic effects of chemicals used in lawn care on an early life stage of freshwater mussels (Utterbackia imbecillis). The chemicals tested were copper and commercial formulations of atrazine, glyphosate, carbaryl, and diazinon. Mussel glochidia were exposed to chemicals singly or in combination (equitoxic and environmentally realistic mixtures) for 24 h and toxic interactions were evaluated with Marking’s additive index. Genotoxicity was quantified with the alkaline single-cell gel electrophoresis assay (Comet assay). In acute tests, copper was the most toxic of all chemicals evaluated (LC50 = 37.4 µg/L) and carbaryl was the most toxic of all pesticides evaluated (LC50 = 7.9 mg/L). In comparison to other aquatic organisms commonly used in toxicity tests (e.g., amphipods, cladocerans, and chironomids), mussel glochidia were as or more sensitive to the chemicals evaluated with the exception of diazinon, where mussels were observed to be less sensitive. The combined toxicity of equitoxic and environmentally realistic mixtures to mussels was additive. Genotoxic responses were observed in mussels exposed to copper, atrazine and diazinon at levels below their respective no-observed-effect concentrations. Together, these data indicate that freshwater mussels are among the most sensitive aquatic organisms tested for some chemicals commonly used in lawn care and that DNA damage may be useful as a screening tool to evaluate potential sublethal effects of lawn care products on non-target aquatic organisms.
Ovipositional Response, Developmental Effects and Toxicity of Hexavalent Chromium to Megaselia scalaris, a Terrestrial Detritivore by John T. Trumble; Peter D. Jensen (pp. 372-376).
The effects of hexavalent chromium (Cr VI) on ovipositional response, development, and survival of a common terrestrial detritivore, Megaselia scalaris (Diptera: Phoridae), were assessed in the laboratory. Ovipositing females did not discriminate between substrates containing 0, 50, 500, or 1000 µg/g, indicating a lack of avoidance behavior. Eggs placed on artificial diets containing up to 1000 µg/g either did not absorb Cr VI or were unaffected as measured by eclosion rates. However, development and survival of larvae were significantly reduced at the higher concentrations tested. Concentrations of 500 µg/g in their food increased larval development times by nearly 65%. At 1000 µg/g, larval developmental times doubled. The time required from onset to completion of pupariation was not significantly different regardless of Cr VI concentration. Although males eclosed before females, there was no significant difference between the sexes in the time required for adult eclosion. In addition, there were no signifi- cant differences in the percentage of males and females emerging from any of the treatments. At concentrations of 500 or 1000 µg/g, Cr VI decreased larval survival. Survival was reduced by 44.3% at 500 µg/g as compared with the controls. There was no additional mortality from the onset of the puparial stage to adult eclosion for larvae fed diets containing 500 µg/g Cr VI. At 1000 µg/g Cr VI, larval survival decreased by 86.6%. An additional 7.4% mortality was recorded in the puparial stage, for a decrease in total survival (larval plus puparial stages) of 94%. Thus, nearly all of the observed mortality occurred during the larval stage rather than the puparial stage. The population level implications of lack of avoidance of contaminated food and the effects of increased developmental times and reduced survivorship are discussed.
Effect of Metal Mixtures (Cd and Zn) on Body Weight in Terrestrial Isopods by J. P. Odendaal; A. J. Reinecke (pp. 377-384).
The aim of this study was to determine the effect of exposure to cadmium and zinc mixtures on the weight of terrestrial isopods. Experiments were conducted using uncontaminated specimens of P. laevis. The isopods were exposed to various concentrations of cadmium and zinc sulfate in single- and mixed-metal experiments. The mean weight of the unexposed isopods in the control group increased over the 6 weeks of observation. It was concluded that cadmium and zinc, administered separately, had a negative effect on the weight of P. laevis. The weight change (gain or loss) of P. laevis in the exposures to mixtures of cadmium and zinc sulfate were different from those of woodlice where Cd and Zn were administered separately. Combination of the lowest concentrations of Cd and Zn (20 and 1000 mg · kg-1) produced a stimulating effect compared to the control. Weight changes of the other two combinations of Cd and Zn (80/4000 and 160/8000 mg · kg-1) showed no differences from those of the control, and weight changes of woodlice exposed to Cd and Zn mixtures were mostly the same as those of the control over the 6-week exposure period. It can thus be concluded that mixtures of Cd and Zn have an antagonistic effect on each other in terms of weight of P. laevis.
Relations Between Land Use and Organochlorine Pesticides, PCBs, and Semi-Volatile Organic Compounds in Streambed Sediment and Fish on the Island of Oahu, Hawaii by A. M. D. Brasher; R. H. Wolff (pp. 385-398).
Bed-sediment and/or fish samples were collected from 27 sites around the island of Oahu (representing urban, agricultural, mixed, and forested land use) to determine the occurrence and distribution of hydrophobic organic compounds including organochlorine pesticides, polychlorinated biphenyls (PCBs), and semi-volatile organic compounds (SVOCs). Of the 28 organochlorine compounds analyzed in the fish, 14 were detected during this study. Nineteen of the 31 organochlorine compounds and 40 of the 65 SVOCs were detected in the sediment. Urban sites had the highest number of detections and tended to have the highest concentrations of pesticides. Chlordane compounds were the most frequently detected constituents at urban sites, followed by dieldrin, polycyclic aromatic hydrocarbons (PAHs), and DDT compounds. PAHs were the most frequently detected constituents in watersheds with mixed (urban and agricultural) land use. The only pesticides detected at agricultural sites were DDT and its degradation products, DDD and DDE. No pesticides or PCBs were detected at the forested sites, but a few ubiquitous SVOCs were found in sediments at some forested sites. In general, concentrations of the most frequently detected pesticides were higher in fish than in sediment. Following a trend that has been observed elsewhere in the nation, concentrations of most organochlorine pesticides and PCBs are decreasing in Hawaii.
Heavy Metal Exposure Affects the Humoral Immune Response in a Free-Living Small Songbird, the Great Tit (Parus major) by Tinne Snoeijs; Tom Dauwe; Rianne Pinxten; Frans Vandesande; Marcel Eens (pp. 399-404).
Although many studies have investigated possible effects of heavy metal contamination on components of the immune system in captive birds, studies on the effects of chronic exposure to heavy metals on the immune system of free-living birds are rare. Therefore we studied the effect of heavy metal exposure on the humoral immune responsiveness in free-living great tit (Parus major) populations from four study sites along a pollution gradient near a metallurgic smelter. Although there were no differences in body condition or hematocrit values among great tits from the four study sites, the heavy metal exposure appeared to affect an individual’s humoral immune responsiveness, as measured by antibody titers to sheep red blood cells. Great tits from the study site farthest away from the smelter complex had a significantly higher immune responsiveness than birds from the two areas closest to the metallurgic smelter. Further work is now necessary to establish a causal association between heavy metal contamination and immunosuppression.
Occurrence of PCBs, Organochlorine Insecticides, tris(4-Chlorophenyl)methane, and tris(4-Chlorophenyl)methanol in Human Breast Milk Collected from Cambodia by Tatsuya Kunisue; Masayuki Someya; In Monirith; Mafumi Watanabe; Touch Seang Tana; Shinsuke Tanabe (pp. 405-412).
The present study determined the concentrations of persistent organochlorines (OCs) such as DDT and its metabolites (DDTs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs), tris(4-chlorophenyl)methane (TCPMe), and tris(4-chlorophenyl)methanol (TCPMOH) in human breast milk from Cambodia. DDTs, PCBs, HCHs, HCB, CHLs, and TCPMe were detected in almost all the human breast milk samples analyzed, and the concentrations ranged from 310 to 11,000, 6.0 to 87, <0.12 to 21, <0.12 to 8.1, <0.12 to 5.3, and 2.9 to 70 ng/g lipid wt, respectively. TCPMOH was detected in only 10 among 36 samples. Concentrations of DDTs in human breast milk from Cambodia were notably higher than those from developed countries and comparable to those from other developing countries, where usage of DDT for agricultural and public health purposes has been suspected to be continuing still, implying the recent usage of DDT in Cambodia. On the other hand, concentrations of PCBs, HCHs, HCB, and CHLs in human breast milk from Cambodia were 1–2 orders of magnitude less than those from other countries, indicating that Cambodia is one of the less contaminated countries by these OCs. Significant correlation between concentrations of TCPMe and DDTs in human breast milk suggested that exposure to DDT is the source of TCPMe in Cambodian residents. Concentrations of OCs in human breast milk tended to decrease with an increase in the number of children, implying that the first infant would be exposed to higher levels of OCs from breast milk and might be at higher risk by these contaminants, especially DDTs in Cambodia. To our knowledge, this is the first comprehensive study on the residue levels of OCs in human breast milk from Cambodia.
No Effects of Hematuria and Proteinuria in School Days, and Probably Current Pregnancy and Current Lactation Also, as Risk Factors of Cadmium-Induced Renal Tubular Dysfunction Among Adult Women in General Populations in Japan by T. Tsukahara; T. Ezaki; J. Moriguchi; K. Furuki; Y. Fukui; H. Ukai; S. Okamoto; H. Sakurai; M. Ikeda (pp. 413-418).
This study was initiated to examine if hematuria and proteinuria in school days, current pregnancy, or current lactation are risk factors of cadmium-induced tubular dysfunction for adult women among general populations in Japan. For this purpose, a database of 9,967 never-smoking adult women were reviewed for urinary levels of cadmium (Cd) and three other elements, calcium (Ca), magnesium (Mg), and zinc (Zn), and two tubular dysfunction markers of α1-microglobulin (α1-MG) and β2-microglobulin (β2-MG); the analyte concentrations were corrected for creatinine (cr) and expressed as, e.g., Cd- Ucr. From the total, 160 cases were selected as those who were informed of urinary abnormality (i.e., proteinuria, hematuria, or both) in their school days (the abnormality being found to be transient, later), and each case was matched by age and prefecture of residence. Separately, seven women with persistent urinary abnormality, seven pregnant women, and six lactating women were identified, and the case was matched with three cases each of the same age and living in the same prefecture. Statistical analyses showed that Cd-Ucr and other markers were not elevated in the transient urinary abnormality group as compared with the matched controls. This was also observed in the subjects with persistent abnormality. In the pregnant women, α1-MG-Ucr and possibly β2-MG-Ucr were elevated, but Cd-Ucr did not increase, suggesting that the observed elevation in α1-MG and β2-MG was not due to the effects of Cd but a part of the physiology of pregnancy itself. There was no change in marker levels in lactating women except for an increase in α1-MG. In overall evaluation, it was considered prudent to conclude that urinary abnormality in school days does not increase the risk of Cd-induced nephrotoxicity in adult women, whereas the negative findings with pregnancy and lactation should be taken as preliminary because the numbers of cases studied were limited.