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Archives of Environmental Contamination and Toxicology (v.49, #4)
Occurrence of Pesticides, Polychlorinated Biphenyls (PCBs), and Heavy Metals in Sediments From the Dniester River, Moldova by Yelena Sapozhnikova; Elena Zubcov; Natalia Zubcov; Daniel Schlenk (pp. 439-448).
The aim of this study was to evaluate sediments of the Dniester River, in the former Soviet republic of Moldova, for the occurrence of agricultural pesticides, polychlorinated biphenyls (PCBs), and heavy metals. In October 2001, sediment samples were collected at three locations of the Dniester River: upstream, downstream, and at the tributary of the River Byk. DDT and its metabolites were observed most frequently. Total DDT sediment concentrations ranged from 8.2 to 34.7 ng/g dry weight with the highest average concentration detected at the tributary location. Heptachlor epoxide (< 0.2–3.0 ng/g dry weight), chlordane (< 0.1–6.1 ng/g dry weight), endrin (< 0.2–2.5 ng/g dry weight), phosalone (< 0.2–1.1 ng/g dry weight), and methylparathion (< 0.2–16.8 ng/g dry weight) were also detected. Total PCB concentrations observed in sediments ranged from 68 to 763 ng/g dry wt. Total average PCB concentrations were significantly (p ≤ 0.004) higher for sediments from the downstream sampling sites compared to the upstream samples. Tetra- and trichlorobiphenyls accounted for 84 and 88% of the total residues measured in the downstream and tributary locations, respectively. In contrast, heptachlorobiphenyls were the prevailing homologues in sediments from the upstream sampling site, contributing 51% of the total PCB concentration. Predominant PCB homologues were: trichlorobiphenyl congener 28 and 37, tetrachlorobiphenyl congeners 44, 49, 52, 74, 77, and 81, and heptachlorobiphenyl congener 170. Sediment concentrations of ΣDDE (19.7 ng/g dry weight) in the tributary, heptachlor epoxide (3.0 ng/g dry weight) in the downstream, and nickel (128–170 μg/g dry weight) in all locations exceeded Probable Effect Levels (PELs) established for sediment quality in fresh water, indicating probable environmental stress and the potential for adverse effects to benthic organisms in the Dniester River.
Presence of Chlorinated Paraffins in Sediments from the North and Baltic Seas by Jan Hüttig; Michael Oehme (pp. 449-456).
Chloroparaffins (CPs) were determined in sediments collected from the North and Baltic Seas during monitoring campaigns in 2001–2003. Electron ionization tandem mass spectrometry (MS/MS) was used for a first screening. It allowed the simultaneous determination of short (SCCP) and medium chain chlorinated paraffins (MCCP). SCCP+MCCP concentrations between 5 and 499 ng/g dry weight were found. In general, Baltic Sea sediments were more highly contaminated by CPs than the North Sea was. However, concentrations related to the total organic carbon content were on the same order of magnitude due to the higher organic content in the Baltic Sea. Additional information about the congener and homologue pattern was obtained for selected samples from the Baltic Sea by high-resolution gas chromatography combined with negative ion chemical ionization and low-resolution mass spectrometry, Concentrations in the North Sea were in general too low for this approach. In the Baltic Sea, MCCP concentrations were 1.7–2.4 times higher than for SCCPs. Lower chlorinated C13 and C14 compounds were the main CP compounds. The CP congener and homologue patterns showed similarities with technical SCCP and MCCP mixtures when compared using principal component analysis.
Sources of Organic Compounds in Fine Soil and Sand Particles During Winter in the Metropolitan Area of Riyadh, Saudi Arabia by Ahmed I. Rushdi; Khalid Al-Mutlaq; Bernd R. T. Simoneit (pp. 457-470).
Major advances have been made in molecular marker analysis to distinguish between natural and anthropogenic organic matter inputs to the atmosphere. Resuspension of soil and sand by wind is one of the major mechanisms that produces particle dusts in the atmosphere. Soil and sand samples from the Riyadh area were collected in winter 2002, sieved to remove coarse particles and extracted with a mixture of dichloromethane and methanol (3:1, v:v). The total extracts were analyzed by gas chromatography–mass spectrometry in order to characterize the contents and identify the potential sources of the organic components. The major organic compounds of these extracts were derived from natural biogenic and anthropogenic sources. Organic compounds from natural sources, mainly vegetation, were major in samples from outside the city of Riyadh and included n-alkanes, n-alkanoic acids, n- alkanols, methyl alkanoates, and sterols. Anthropogenic inputs were significant in the fine particles of soil and sand samples collected from populated areas of the city. They consisted mainly of n-alkanes, hopanes, UCM (from vehicular emissions), and plasticizers (from discarded plastics, e.g., shopping bags). Carbohydrates had high concentrations in all samples and indicate sources from decomposed cellulose fibers and/or the presence of viable microbiota such as bacteria and fungi.
A Rapid Radiochemical Bacterial Bioassay to Evaluate Copper Toxicity in Freshwaters by N. J. Rogers; S. C. Apte; A. Knapik; C. M. Davies; K. C. Bowles; S. H. Kable (pp. 471-479).
A rapid, highly sensitive bacterial bioassay to determine copper toxicity in freshwaters was developed based on the inhibition of cellular assimilation of radiolabeled glucose. The test used a copper-sensitive bacterium isolated from a freshwater stream. Employing sensitive radiochemical techniques enabled environmentally relevant concentrations of the test bacterium (105 cells mL−1) and a short incubation period (4 hours) to be used, which minimized the potential for changes in copper speciation during the test. The 4-hour median effective concentration (EC50) for inorganic copper at pH 7.5 in synthetic freshwater was 0.6 μg L−1 (95% confidence limits 0.4 to 1.0 μg L−1). This compared well with chronic growth inhibition of this bacterium in minimal medium (48-hour EC50 of 0.9 μg L−1 [95% confidence limits 0.7 to 1.0 μg L−1 ]). MINEQL + software (Environmental Research Software) was used to calculate copper (II) ion concentrations in synthetic freshwater at pH 7.5, giving an EC50 value of pCu2+ 8.8. However, using nitrilotriacetic acid metal-ion buffers (Cu-NTA), 50% inhibition occurred at a pCu2+ of 9.7, suggesting this bacterium was markedly more inhibited by copper in these Cu2+-buffered solutions. This may indicate that the Cu-NTA species was contributing to toxicity. The radiochemical bioassay was evaluated further using freshwater samples from both copper-impacted and pristine environments. Measured EC50 values ranged from 3.4 to 34.0 μg L−1 inorganic copper and were strongly correlated with dissolved organic carbon (DOC) concentrations (r = 0.88, p < 0.05).
Assessing the Detoxication Efficiencies of Wastewater Treatment Processes Using a Battery of Bioassays/Biomarkers by Mei Ma; Jian Li; Zijian Wang (pp. 480-487).
A battery of in vitro bioassays, including a Neutral Red (NR) assay using MCF-7 cells for predicting cytotoxic chemicals, an ethoxy resorufin-O-deethylase (EROD) activity assay using H4IIE cells to check for dioxin-like chemicals, and a recombinant gene yeast assay for screening estrogenic chemicals, was conducted to assess the removal efficiencies of trace toxic chemicals by different treatment processes in the waste water treatment plant (WWTP). The effluents were extracted by solid phase extraction (SPE) and were fractionated into three fractions based on polarities. The battery of bioassays was performed for each fraction. In the battery, the toxicities of the effluents were described according to their modes of actions (MOA) or biomarkers and the properties of the toxic chemicals were categorized by their polarities and MOAs. The proposed procedure could be used as a tool to diagnose the toxic characteristics of the complicate mixture. The results showed that cytotoxic, dioxin-like and estrogenic chemicals could be detected in all samples. In the influent, cytotoxic and dioxin-like chemicals were mainly in polar fraction and estrogenic chemicals were in non-polar and moderate-polar fractions. The secondary treatment (active sludge) could remove a small amount of these toxicants. Among different types of advanced treatments, flocculation was good enough to remove most of the cytotoxic chemicals and a combination of flocculation, ozone oxidation, and post-biological treatment could eliminate most of the dioxin-like and estrogenic chemicals.
Bioassessment of an Appalachian Headwater Stream Influenced by an Abandoned Arsenic Mine by Theodore W. Valenti; Jake L. Chaffin; Donald S. Cherry; Madeline E. Schreiber; H. Maurice Valett; Megan Charles (pp. 488-496).
Recent debate concerning the modification of safe drinking water standards for arsenic (As) has led to increased awareness of the risks As poses to both humans and the environment. However, few studies have examined the effects of As on the diversity and composition of aquatic assemblages in streams. Benthic macroinvertebrate surveys, chemical analysis of water column and sediment, and laboratory toxicity tests were conducted to assess effects of an abandoned As mine on a headwater stream, and to determine the primary component of toxicity. The average 48-hr LC50 value for Daphnia magna was 4316 μg As/L, and the average 96-hr LC50 value for Lepidostoma spp. was 2138 μg As/L. Reproduction was significantly reduced for D. magna at concentrations ≥312 μg As/L in water column laboratory bioassays, and for treatments in bioassays with sediments containing elevated As (≥2630 mg/kg). These results support the findings of the in-stream benthic macroinvertebrate survey as the density and percent Ephemeroptera + Plecoptera, + Trichoptera (EPT) were substantially lower at sites downstream of the mine compared to upstream reference sites. Results of bioassays comparing the toxicity of As-contaminated site water and upstream reference water spiked with As salts suggest that As is the primary component of toxicity impacting the stream. Measured As concentrations at downstream sites were above the recommended Criterion Maximum Concentration of 340 μg As/L and Criterion Continuous Concentration of 150 μg As/L for protection of aquatic life published by the United States Environmental Protection Agency. At the study site, elevated As concentrations likely prevent recruitment of benthic macroinvertebrates and recovery of the perturbed headwater stream.
Accumulation of Organotin Compounds in the Deep-Sea Environment of Nankai Trough, Japan by Hiroya Harino; Nozomu Iwasaki; Takaomi Arai; Madoka Ohji; Nobuyuki Miyazaki (pp. 497-503).
The concentration of butyltin (BT) and phenyltin (PT) compounds was measured in sediment, gastropods (Colliloconcha nankaiensis), sea cucumbers (Psychropotes verrucosa), galatheid crabs (Munidopsis albatrossae and Munidopsis subsquamosa), and bivalves (Clyptogena tsubasa and Clyptogena nautilei) collected from the Nankai Trough (water depth about 3000 m). Sediment at depths of up to 1 cm was taken by a core sampler and at depths of up to 15 cm was taken by rake. The concentration of BTs in sediment core from a depth of 0–1 cm (0.041 mg kg−1 dry) was higher than in sediment core from 0–15 cm (0.021 mg kg−1 dry). The relative proportion of different BTs in the 0–1-cm sediment core was similar to that in the 0–15-cm sediment core, but the concentration of PTs in the former (0.028 mg kg−1 dry) was lower than in the latter 0–15 cm (0.052 mg kg−1 dry). Organotin (OT) compounds were also detected in deep-sea organisms. The means of BT concentrations in C. nankaiensis, P. verrucosa, M. albatrossae, M. subsquamosa, Cl. tsubasa, and Cl. nautilei were, respectively, 0.089, 0.057, 0.018, 0.016, 0.019, and 0.026 mg kg−1. The corresponding concentrations of PTs were 0.212, 0.363, 0.166, 0.186, 0.030, and 0.025 mg kg−1. High concentrations of BTs and PTs were observed in gastropods and sea cucumbers. The species of deep-sea organism can be classified by δ13C value into two groups (A and B). The organisms in group A use organic matter chemosynthesized by symbiotic bacteria while those in group B depend on photosynthesis carried out near the surface by phytoplankton. No difference in BT or TBT concentration is observed between the two groups, but PT and TPT concentrations are higher in group B. Trophic levels in the food chain are often estimated using δ15N values. Group B showed a higher trophic level than group A. Although no change in BT and TBT concentration was observed to accompany increases of δ15N values, PT and TPT concentrations generally increased with increasing δ15N values. The compositions of BTs in deep-sea organisms were calculated. An increasing proportion of MBT and a declining proportion of DBT were observed at higher trophic levels. No correlation between the shell length of Cl. nautilei and BT or PT concentration was observed. The average partition coefficients of TBT for C. nankaiensis, P. verrucosa, M. albatrossae, M. subsquamosa, Cl. Tsubasa, and Cl. nautilei were 2.6, 0.72, 0.63, 0.19, 0.43, 0.30, and 0.46.
Partial Characterization of Proteins from Mussel Mytilus galloprovincialis as a Biomarker of Contamination by S. Gorinstein; S.-T Jung; S. Moncheva; P. Arancibia-Avila; Y.-S Park; S.-G Kang; I. Goshev; S. Trakhtenberg; J. Namiesnik (pp. 504-510).
Preservation of a healthy environment is a very important task, especially in the time of the total industrial revolution. Therefore, attempts to find new additional biomarkers of contamination are welcomed. For this aim, the functional and antioxidant properties of mussel Mytilus galloprovincialis proteins and the heavy metals Cd and Pb were explored. Mussels were collected in contaminated and noncontaminated sites in the Varna area of the Bulgarian Black Sea coast. Proteins were extracted from mussel entire soft tissue and analyzed using instrumental (Fourier transform infrared [FT-IR] spectroscopy, fluorescence, atomic absorption spectrophotometry), and biochemical (2,2′-azinobis 3-ethylbenzothiazoline-6-sulfonate) radical cation [ABTS•+]) methods. It was found that mussel proteins from the contaminated sites had specific qualitative changes: partial unfolding of the α-helix, slight shift in amide I bands, increased hydrophobicity, and fluorescent intensity in native and denatured samples. In the same mussel samples, an increased radical-scavenging capacity and increased contents of Cd and Pb in entire soft tissue were registered. Therefore, the above-mentioned indices could be used as additional biomarkers of sea water contamination.
Effects of Pulsed Contaminant Exposures on Early Life Stages of the Fathead Minnow by Jerome Diamond; Marcus Bowersox; Henry Latimer; Chad Barbour; Jonathan Bearr; Jonathan Butcher (pp. 511-519).
Water quality standards for protecting aquatic life are based primarily on laboratory tests that use constant exposure concentrations. Typical effluent and nonpoint source exposure concentrations fluctuate in frequency, magnitude, and duration, which may result in different toxicological impacts. Current information indicates that pulsed or fluctuating exposures are generally more toxic than continuous exposures, when averaged over the applicable time period. However, few studies have evaluated chronic or sublethal effects of pulsed exposures, particularly those applicable to wastewater discharge situations. To address this issue, several pulsed exposure toxicity tests were conducted using modified fathead minnow (Pimephales promelas) early life stage (7 d) tests and several chemicals representative of those commonly encountered in wastewater effluents including copper, nitric acid, cadmium, and sodium chloride. Results suggest that survival and/or growth effects depend on the combination of frequency, magnitude, and duration, as well as the type of chemical. Nitric acid and sodium chloride pulsed treatments did not exhibit growth effects independent of survival effects, but both metals did elicit only growth effects in some treatments. Growth effects were related to pulse frequency and duration for copper and pulse duration and magnitude for cadmium. A 12-h exposure of approximately five times the 7-d continuous exposure IC25 concentration of either metal quickly elicited mortality responses. Prolonged (>24 h) lag effects on survival were not observed in any of the experiments, regardless of the contaminant tested. Our results suggest that current water quality criteria may be underprotective if based on an average concentration over a 2-4 d exposure. For these contaminants, a short-term increase in concentration may elicit effects even though the average concentration is within nontoxic ranges for the organism.
The Influence of Dietary Na on Cu Accumulation in Juvenile Rainbow Trout Exposed to Combined Dietary and Waterborne Cu in Soft Water by Victoria A. Kjoss; Martin Grosell; Chris M. Wood (pp. 520-527).
Fish inhabiting metal-contaminated environments can take up metals such as Cu via the gills as well as via the gut. Previous research on rainbow trout (Oncorhynchus mykiss) has indicated that dietary Na can reduce the accumulation of waterborne Cu; however, in hard water, dietary Na does not reduce the accumulation of dietary Cu. In this study, we exposed juvenile rainbow trout in soft water with slightly elevated [Cu] for 28 days to control or high levels of dietary Cu (6 and 580 μg Cu/g food, respectively) at low (1.5%), intermediate (3%), or high (4.5%) levels of dietary Na, for a total of six experimental groups. A separate gastrointestinal sampling experiment demonstrated that these levels resulted in moderately elevated Na concentrations in the gastrointestinal fluid, which declined between 6 h and 12 h post-feeding. Growth and condition indices were not affected by the dietary Cu and Na exposure. Among the control dietary Cu groups, those that received the highest amount of dietary Na had significantly higher whole-body [Cu] on days 18 and 28. In contrast, among the high-Cu groups, fish that were fed the highest amount of Na tended to have significantly lower whole-body [Cu] on days 9 and 18. Tissue Na concentrations did not differ among any of the groups, and unidirectional Na flux measurements demonstrated that Na homeostasis was not impaired by dietary or waterborne Cu. Our results suggest that elevated dietary Na stimulates Cu uptake via the gut under low-Cu conditions, thereby increasing whole-body [Cu], whereas under Cu-loaded conditions, downregulation of Cu uptake at the gills, and/or competitive inhibition of gut Cu uptake as a result of increased dietary Na, leads to decreased whole-body [Cu].
Factors Controlling Mercury and Methylmercury Concentrations in Largemouth Bass (Micropterus salmoides) and Other Fish from Maryland Reservoirs by Audur Yr Sveinsdottir; Robert P. Mason (pp. 528-545).
The concentration of mercury (Hg) and methylmercury (MeHg) was determined for largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus) and black crappie (Pomoxis nigromaculatus) from Maryland reservoirs. Overall, there was a large difference in normalized bass MeHg concentration (for fish of ∼370 mm) between the reservoirs, ranging from <100 ng g−1 to almost 800 ng g−1. Furthermore, the relationship between fish weight and MeHg concentration varied substantially between lakes, and showed no geographical relationship. The concentration of Hg, MeHg and ancillary parameters were determined in the water and correlations were sought between the normalized concentration of MeHg in bass and both physical and chemical parameters of the reservoirs, as well as the concentration of MeHg in the prey of the largemouth bass. Bass MeHg concentration correlated with dissolved MeHg and dissolved organic carbon, but not with other chemical parameters. There was no relationship to physical characteristics that varied over orders of magnitude for these reservoirs. Dissolved MeHg did not correlate with any chemical or physical attributes. Overall, this study suggests that water column MeHg is a good predictor of fish concentration but that the water column MeHg cannot be predicted based on usually measured chemical and physical characteristics of fresh water bodies.
Acute Toxicity Value Extrapolation with Fish and Aquatic Invertebrates by Denny R. Buckler; Foster L. Mayer; Mark R. Ellersieck; Amha Asfaw (pp. 546-558).
Assessment of risk posed by an environmental contaminant to an aquatic community requires estimation of both its magnitude of occurrence (exposure) and its ability to cause harm (effects). Our ability to estimate effects is often hindered by limited toxicological information. As a result, resource managers and environmental regulators are often faced with the need to extrapolate across taxonomic groups in order to protect the more sensitive members of the aquatic community. The goals of this effort were to 1) compile and organize an extensive body of acute toxicity data, 2) characterize the distribution of toxicant sensitivity across taxa and species, and 3) evaluate the utility of toxicity extrapolation methods based upon sensitivity relations among species and chemicals. Although the analysis encompassed a wide range of toxicants and species, pesticides and freshwater fish and invertebrates were emphasized as a reflection of available data. Although it is obviously desirable to have high-quality acute toxicity values for as many species as possible, the results of this effort allow for better use of available information for predicting the sensitivity of untested species to environmental contaminants. A software program entitled “Ecological Risk Analysis” (ERA) was developed that predicts toxicity values for sensitive members of the aquatic community using species sensitivity distributions. Of several methods evaluated, the ERA program used with minimum data sets comprising acute toxicity values for rainbow trout, bluegill, daphnia, and mysids provided the most satisfactory predictions with the least amount of data. However, if predictions must be made using data for a single species, the most satisfactory results were obtained with extrapolation factors developed for rainbow trout (0.412), bluegill (0.331), or scud (0.041). Although many specific exceptions occur, our results also support the conventional wisdom that invertebrates are generally more sensitive to contaminants than fish are.
Effects of Nitrate on the Tadpoles of Two Ranids (Rana catesbeiana andR. clamitans) by G R Smith; K G Temple; D A Vaala; H A Dingfelder (pp. 559-562).
Nitrate is a potential stressor of amphibian larvae. Previous research has shown variation in the effects of nitrate among species and even populations of amphibians. However, relatively few species and populations of amphibians have been examined for nitrate tolerance, especially from populations in the agricultural regions of the United States. Using a 15-day laboratory experiment, we investigated the effects of nitrate on the larvae of two species of anurans (Rana catesbeiana and R. clamitans) that are common throughout the agricultural Midwest. Survival of R. catesbeiana and R. clamitans tadpoles was negatively affected by higher concentrations of nitrate (20 mg L–1), with R. clamitans being more affected than R. catesbeiana. The final mass of R. catesbeiana tadpoles was affected by nitrate concentration, with tadpoles exposed to intermediate concentrations of nitrate (5 mg L–1) being the heaviest. The final mass of R. clamitans tadpoles was not affected by nitrate concentration. These experiments suggest that these two species differ in their responses to the toxic effects of nitrate and, along with previous results on Ranids, suggest there is a great deal of variation in nitrate tolerance in this family.
Organochlorine Contamination and Physiological Responses in Nestling Tree Swallows in Point Pelee National Park, Canada by Z. Papp; G. R. Bortolotti; J. E. G. Smits (pp. 563-568).
Point Pelee National Park in southwestern Ontario, Canada—a major migratory route and vital breeding area for many birds—has localized areas of organochlorine (OC) contamination from the 1950s and 1960s. During 2002, we investigated the effect of tissue OC contaminant levels on the physiology and growth of nestling tree swallows (Tachycineta bicolor). Polychlorinated biphenyl (PCB) contamination in the nestlings positively correlated with hepatic ethoxy-, benzyloxy-, and pentoxyresorufin-o-dealkylase enzyme activities and liver size. Despite detectable physiologic changes associated with body burdens of PCBs, reproductive success of breeding pairs was not affected. Hatching date was negatively correlated with PCB levels, alkoxyresorufin-O-dealkylase (alkROD) activities, liver size, and serum protein levels. alkROD activities were largely dependent on hatching date because insect prey contaminated with PCBs were only abundant during a limited period of time during the breeding season.
The Distribution of Arsenic in the Body Tissues of Wood Mice and Bank Voles by B. V. Erry; M. R. Macnair; A. A. Meharg; R. F. Shore (pp. 569-576).
Arsenic is accumulated by free-living small mammals, but there is little information on the resultant concentrations in different tissues other than liver and kidney. Such information is important because the severity of toxicological effects may be related to the amount of arsenic accumulated in specific organs, and the availability of arsenic to predators is, in part, dependent on which tissues accumulate arsenic. The objective of this study was to quantify the arsenic concentrations and the percentage of the total body burden (%TBB) accumulated in different body tissues of free-living small mammals and to determine how these factors varied with severity of habitat contamination. Arsenic concentrations were measured in various tissues of wood mice (Apodemus sylvaticus) and bank voles (Clethrionomys glareolus) from a range of arsenic-contaminated sites in southwest Britain. Arsenic concentrations in the gastrointestinal (GI) tract (including contents), liver, kidneys, spleen, lung, femur, and fur of both species varied significantly between sites and were higher in mice and voles from heavily contaminated areas. Heart and brain arsenic concentrations did not vary with degree of environmental contamination. The GI tract and excised carcass contained roughly equal amounts of arsenic and, in sum, comprised 75–85% of the TBB on uncontaminated sites and 90–99% on contaminated sites. Although the excised carcass contains about half of the TBB, its importance in food-chain transfer of arsenic to predators may depend on the bioavailability of arsenic sequestered in fur. In contrast, the GI tract and its contents, provided that it is consumed, will always be a major transfer pathway for arsenic to predators, regardless of the severity of habitat contamination.
Exposure to Omethoate During Stapling of Ornamental Plants in Intensive Cultivation Tunnels: Influence of Environmental Conditions on Absorption ofthe Pesticide by C. Aprea; L. Centi; S. Santini; L. Lunghini; B. Banchi; G. Sciarra (pp. 577-588).
This report describes a study of exposure to omethoate during manual operations with ornamental plants in two intensive cultivation tunnels (tunnel 8 and tunnel 5). Airborne concentrations of omethoate were in the range 1.48–5.36 nmol/m3. Total skin contamination in the range 329.94–12,934.46 nmol/day averaged 98.1 ± 1.1% and 99.3 ± 0.6% of the total potential dose in tunnel 8 and tunnel 5, respectively. Estimated absorbed doses during work in tunnel 5 were much higher than the acceptable daily intake of omethoate, which is 1.41 nmol/kg b.w. This finding shows that organization of the work or the protective clothing worn in tunnel 5 did not protect the workers from exposure. Urinary excretion of alkylphosphates was significantly higher than in the general population, increasing with exposure and usually showing a peak in the urine sample collected after the work shift. Urinary alkylphosphates showed a good correlation with estimated potential doses during work in tunnel 8 and are confirmed as sensitive biological indicators of exposure to phosphoric esters. The linear regression analysis between the urinary excretion of alkylphosphate, expressed as total nmol excreted in 24 h, and total cutaneous dose allows for estimating that the fraction of omethoate absorbed through the skin during work in tunnel 8 is about 16.5%.
The Elbmarsch Leukemia Cluster: Are There Conceptual Limitations in Controlling Immission from Nuclear Establishments in Germany? by I. Schmitz-Feuerhake; H. Dieckmann; W. Hoffmann; E. Lengfelder; S. Pflugbeil; A. F. Stevenson (pp. 589-600).
The childhood leukemia cluster in the proximity of the German nuclear establishments of Geesthacht is unique in its spatial and temporal concentration. After a steep increase in cases in 1990, the cluster continues to show a significant increase up to the present. Early investigations of blood samples from a casual sample of local residents showed an increase in dicentric chromosomes in lymphocytes, indicating exposure exceeding dose limits. Analyses of the immission data revealed several unexpected deliveries of fission and activation products in the environment but provided no explanation of the source. Because of the observed overdispersion of dicentric chromosomes in cells, the idea of a contribution by densely ionizing emitters was compelling. The routine programs, however, do not include alpha emitters. These were measured in specific studies that proved contamination by transuranic nuclides. As shown in the present investigation, routine environmental surveillance programs support the occurrence of an accidental event near Geesthacht in September 1986. Until now, neither the cause nor the complete scenario of the activity release could be established. The ongoing discussion highlights limitations in the immission-control concept, which is predominantly based on gamma-radiation monitoring.
Partial Characterization of Proteins from Mussel Mytilus galloprovincialis as a Biomarker of Contamination
by S. Gorinstein; S.-T. Jung; S. Moncheva; P. Arancibia-Avila; Y.-S. Park; S.-G. Kang; I. Goshev; S. Trakhtenberg; J. Namiesnik (pp. 601-601).