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Archives of Environmental Contamination and Toxicology (v.38, #3)
Evaluation of Co-Solvents with Supercritical Fluid Extraction of Atrazine from Soil by S. A. Senseman; M. L. Ketchersid (pp. 263-267).
Supercritical fluid extraction (SFE) with CO2 has been successfully applied to herbicide extractions from soil. The objectives of this work were to compare extraction efficiency of atrazine from soil using different types and quantities of co-solvent modifiers under a specified set of SFE instrument conditions and to determine the ruggedness of an optimized extraction program and co-solvent on several soils with varying characteristics. The effect of 18 co-solvents on atrazine extraction from Lufkin fine sandy loam was determined using a completely randomized design with six replications. Extractions of Lufkin soil using the more nonpolar co-solvents had recovery similar to extractions where no co-solvent was added. The co-solvents that showed high extraction efficiency, low incidences of restrictor plugging, and ease of cleaning extraction cells were acetone, acetone:water mixtures (with and without 1% triethylamine), and acetonitrile. The addition of 1% triethylamine (TEA) did not increase recovery significantly. The 9:1 acetone:water mixture with 1% TEA was used for the soil comparison because of the high atrazine recovery and low water content. No differences in atrazine recovery were detected between extractions of the four representative soils when the same extraction conditions were employed. No cleanup steps were included in the procedure, yet adequate chromatography results were obtained suggesting some selectivity for this procedure. These data indicate that SFE with optimized conditions and appropriate co-solvents is a relatively robust method that can effectively be used in soil extractions of atrazine.
Fungal Biomass in Saltmarsh Grass Blades at Two Contaminated Sites by S. Y. Newell; V. D. Wall; K. A. Maruya (pp. 268-273).
Ascomycetous fungi are the principal drivers of the decomposition of shoots of smooth cordgrass (Spartina alterniflora). Shoots of smooth cordgrass move into the saltmarsh food web via the decomposition system. Therefore, influences on saltmarsh ascomycetes by pollutants of saltmarshes could have far-reaching impacts. Earlier examination of impacts of severe contamination of a Georgia saltmarsh by mercury and polychlorinated biphenyls (PCBs) revealed little or no influence of the toxicants on living standing crops or sexual productivities of cordgrass ascomycetes. Extension of the examination of saltmarsh-ascomycete response to sites containing other toxic pollutants (the chlorinated organocyclic insecticide toxaphene; chromium, copper, and lead; and polycyclic aromatic hydrocarbons [PAHs]) has shown that none of the additional toxicants engendered saltmarsh-fungal responses in the form of reduced living standing crops or sexual productivities. Thus the ascomycetes of the cordgrass-decay system appear to be as resistant to anthropogenic-pollutant poisoning as smooth cordgrass itself. Unless the fungal and plant resistance mechanisms involve degradation of the toxicants, this may imply that saltmarshes are especially dangerous as receiving sites for toxic waste because they may have the potential to readily move toxicants into the food web.
Phototoxic Evaluation of Marine Sediments Collected from a PAH-Contaminated Site by B. L. Boese; R. J. Ozretich; J. O. Lamberson; F. A. Cole; R. C. Swartz; S. P. Ferraro (pp. 274-282).
The phototoxicity potential of PAH-contaminated field sediment was evaluated and compared to standard sediment toxicity test results. Marine sediments were collected from 30 sites along a presumed PAH sediment pollution gradient in Elliot Bay, WA. Standard 10-day acute and 28-day chronic sediment toxicity tests were conducted with the infaunal amphipods Rhepoxynius abronius and Leptocheirus plumulosus using mortality and the ability to rebury as endpoints. The survivors of these tests were then subjected to 1-h exposures to UV radiation with mortality and reburial again determined. The most highly toxic sediments identified in these experiments were evaluated further for toxicity and phototoxicity by serially diluting them with uncontaminated sediment and repeating the toxicity tests. Standard 10-day toxicity test results indicated that over 70% of the sites sampled in Elliot Bay exhibited measurable toxicity with nine sites being highly toxic to both species of amphipods. Results of standard 28-day chronic sediment toxicity tests were similar. In contrast, almost all of the sites were found to be highly phototoxic. Results indicated that exposure to UV increased toxicity five- to eightfold. This suggests that standard toxicity tests underestimate the potential ecological risk of PAH-contaminated sediments in animals exposed to sunlight. However, only when PAH contamination was between 0.05 and 1.0 toxic units would conducting a phototoxicity evaluation add information to that gained from conducting a standard sediment toxicity test alone.
Factors Controlling the Bioaccumulation of Mercury, Methylmercury, Arsenic, Selenium, and Cadmium by Freshwater Invertebrates and Fish by R. P. Mason; J.-M. Laporte; S. Andres (pp. 283-297).
Concentrations of mercury (Hg), methylmercury (MMHg), arsenic (As), selenium (Se), and cadmium (Cd) were measured in atmospheric deposition, stream water, and biota in two streams in western Maryland. Overall, concentrations were slightly higher in the water of the lower pH Herrington Creek tributary (HRCT). Bioaccumulation factors were also higher for HRCT compared to Blacklick Run (BLK). MMHg concentrations in biota increased with trophic level and essentially all the Hg was as MMHg in predatory insects and insectivorous/carnivorous fish. Thus, the overall trophic status of the organism was indicated by the %MMHg in its tissues. Levels of As, Se, Cd, and Hg, however, decreased with increasing trophic level. Adsorption of As to the exoskeleton of invertebrates appears to be an important accumulation mechanism. MMHg was distributed evenly throughout crayfish and fish organs, whereas As, Se, Cd, and Hg were found in higher concentrations in detoxifying organs. Concentrations in biota in this study were somewhat elevated compared to other rural sites, but were less than those of point source–contaminated sites. Overall, as atmospheric inputs to the two watersheds were similar, the results of this study show the importance of water chemistry in determining the bioaccumulation of the metals and metalloids into insects. Subsequent transfer to higher trophic levels is related to both the ability of the organisms to depurate and the mode of accumulation, either directly from water or from food.
Toxicity of Manganese to Ceriodaphnia dubia and Hyalella azteca by P. J. Lasier; P. V. Winger; K. J. Bogenrieder (pp. 298-304).
Manganese is a toxic element frequently overlooked when assessing toxicity of effluents, sediments, and pore waters. Manganese can be present at toxic levels in anoxic solutions due to increased solubility under chemically reducing conditions, and it can remain at those levels for days in aerated test waters due to slow precipitation kinetics. Ceriodaphnia dubia and Hyalella azteca are freshwater organisms often used for toxicity testing and recommended for assessments of effluents and pore waters. Lethal and reproductive-inhibition concentrations of Mn were determined for C. dubia in acute 48-h tests and chronic three-brood tests using animals <24 h old and between 24 and 48 h old. Sensitivity of H. azteca to Mn was determined with 7-day-old animals in acute 96-h tests. Tests were run at three levels of water hardness to assess the amelioratory effect, which was often significant. Manganese concentrations were measured analytically at test initiation and after 96 h for calculation of toxicity and determination of Mn precipitation during the tests. Minimal amounts of Mn (≤3%) precipitated within 96 h. LC50s determined for H. azteca progressively increased from 3.0 to 8.6 to 13.7 mg Mn/L in soft, moderately hard, and hard waters, respectively. The tolerance of C. dubia to Mn was not significantly different between moderately hard and hard waters, but was significantly lower in soft water. Manganese sensitivity of C. dubia was not significantly different between the ages tested. Acute LC50 values for C. dubia averaged 6.2, 14.5 and 15.2 mg Mn/L and chronic IC50 values averaged 3.9, 8.5 and 11.5 mg Mn/L for soft, moderately-hard and hard waters, respectively. Manganese toxicity should be considered when assessing solutions with concentrations approaching these levels.
Relative Acute Toxicity of Acid Mine Drainage Water Column and Sediments to Daphnia magna in the Puckett's Creek Watershed, Virginia, USA by D. J. Soucek; D. S. Cherry; G. C. Trent (pp. 305-310).
Acid mine drainage (AMD) is produced when pyrite (FeS2) is oxidized on exposure to oxygen and water to form ferric hydroxides and sulfuric acid. If produced in sufficient quantity, iron precipitate, heavy metals (depending on soil mineralogy), and sulfuric acid may contaminate surface and ground water. A previous study of an AMD impacted watershed (Puckett's Creek, Powell River drainage, southwestern Virginia, USA) conducted by these researchers indicated that both water column and sediment toxicity were significantly correlated with benthic macroinvertebrate community impacts. Sites that had toxic water or sediment samples had significantly reduced macroinvertebrate taxon richness. The present study was designed to investigate the relative acute toxicity of acid mine drainage (AMD) water column and sediments to a single test organism (Daphnia magna) and to determine which abiotic factors were the best indicators of toxicity in this system. Nine sampling stations were selected based on proximity to major AMD inputs in the watershed. In 48-h exposures, sediment samples from three stations were acutely toxic to D. magna, causing 64–100% mortality, whereas water samples from five stations caused 100% mortality of test organisms. Forty-eight-hour LC50 values ranged from 35 to 63% for sediment samples and 27 to 69% for water column samples. Sediment iron concentration and several water chemistry parameters were the best predictors of sediment toxicity, and water column pH was the best predictor of water toxicity. Based on these correlations and on the fact that toxic sediments had high percent water content, water chemistry appears to be a more important adverse influence in this system than sediment chemistry.
Antipredatory Behavior as an Index of Heavy-Metal Pollution? A Test Using Snails and Caddisflies by H. Lefcort; E. Ammann; S. M. Eiger (pp. 311-316).
The loss of behaviors that organisms use to avoid predation may serve as a sensitive indicator of pollution. We tested the hypothesis that a correlation exists in the field between heavy metal levels and antipredator behaviors. We examined the antipredator behavior of aquatic caddisfly larvae and snails at sites in the Coeur d'Alene basin of Northern Idaho which varied in their levels of heavy metals. We tested the antipredator response of Physella columbiana snails at 10 polluted lakes downstream from the Bunker Hill Environmental Protection Agency (EPA) Superfund cleanup site. We then compared their behavior to snails at 14 reference lakes. We placed the snails in a plastic testing apparatus, exposed them to an extract of crushed snail, and then monitored their movements to a normally preferred shaded area. We also tested the behavior of caddisfly larvae from 36 sites from a total of 6 streams/rivers adjacent to the Superfund site. Sites were located upstream and downstream of abandoned mines. We located active larvae of four genera, simulated predation by grasping the animals between thumb and forefinger (the larvae respond to being grasped by withdrawing into their case), lifted them from the water for 3 s, and then placed them in an adjacent, slower section of the stream. We then recorded how long it took each larvae to partially emerge from its case and attempt to move away. Unlike reference site snails, snails from heavy metal–polluted environments failed to exhibit antipredator behaviors in response to crushed conspecifics. These results are consistent with previous laboratory studies. We found no effect of heavy metals on the antipredatory behavior of caddisfly larvae.
Comparative Experimental Study of Cadmium and Methylmercury Trophic Transfers Between the Asiatic Clam Corbicula fluminea and the Crayfish Astacus astacus by O. Simon; F. Ribeyre; A. Boudou (pp. 317-326).
Cadmium (Cd) and methylmercury (MeHg) trophic transfers were analyzed between the Asiatic clam Corbicula fluminea and the crayfish Astacus astacus. Metal bioaccumulation in crayfish was quantified after 5, 10, and 15 days of exposure via daily ingestion of soft bodies of C. fluminea, previously exposed during 7 days to Cd (20 μg · L−1) and MeHg (4 μg · L−1). Bioaccumulation kinetics in the predator were investigated at organ and tissue levels: hemolymph, tail muscle, hepatopancreas, gills, stomach/mesenteron, intestine, green gland, carapace. Trophic transfer rates were estimated at the whole organism level. Results showed marked differences (1) in assimilation efficiencies, mean transfer rates being 5% for Cd and 16% for MeHg; and (2) in the metal distribution within the different tissue compartments of the crayfish: for Cd, the trophic uptake leads to high concentrations in the hepatopancreas and small accumulation in the muscle tissue; for MeHg, the highest levels of bioaccumulation occur in the green gland and in the tail muscle. From an ecotoxicological point of view, these experimental data suggest a small risk of Cd transfer between the crayfish and predators, humans included; on the other hand, Hg distribution in the muscle and accumulation trends in this tissue represent an obvious risk of transfer.
Effects of Aerially Applied Fenthion on Survival and Reproduction of the Panacea Sand Fiddler, Uca panacea, in Laboratory Habitats by W. P. Schoor; D. P. Middaugh; D. T. Marcovich (pp. 327-333).
Sand fiddler crabs, Uca panacea, were exposed in laboratory habitats to measured concentrations of ULV-grade fenthion via simulated aerial spray at 5% and 50% of field rate application of 6–12 mg fenthion/m2 (0.05–0.10 lbs fenthion/acre). Two habitats served as controls, and two habitats served as replicates for each of the test exposures. The aerial application was repeated 12 times between July 7, 1997, and August 15, 1997, during the period of the most active larval production of the crabs. The resulting measured concentrations of fenthion at the surface and in the water were consistently lower than what the application rate would have suggested. Statistical analysis of total, daily larval counts showed a periodicity of approximately 14 days that did not appear to be affected by fenthion, at least at the 5% application rate, where a 15% reduction in larval production was noted by the end of the second hatching cycle and a 25% reduction by the end of the third. Larval production in the habitats exposed to the 50% application rate was reduced by 18% at the end of the first hatching cycle, 77% at the end of the second, and 100% at the end of the third hatching cycle. At the end of the third hatching cycle, adult crab mortality observed at the surface was 0%, 3%, and 20% for the control, 5%-, and 50%-exposure habitats, respectively. Three weeks after the final fenthion application, survival of adult crabs was 100% in the control habitats, 75% in the 5%-exposure habitats, and 3% in the 50%-exposure habitats. Survival of unfed first-stage zoeae released during the night following the sprays averaged 4.6 ± 0.9, 3.7 ± 0.9 and 1.7 ± 0.6 days for control, 5%-, and 50%-exposure habitats, respectively. Forty-eight-hour LC-50s (nominal) for fenthion exposure of adult crabs submerged in water and for first-stage zoeae were 215 μg fenthion/L and 0.8 μg fenthion/L, respectively.
Environmental Monitoring of the Kafue River, Located in the Copperbelt, Zambia by L. Norrgren; U. Pettersson; S. Örn; P.-A. Bergqvist (pp. 334-341).
Zambia is a country with an extensive mining industry with the majority of mines located in the Copperbelt province. Through this region of the country, the Kafue River drains and receives effluent water from mining activities as well as from other industrial point sources. In addition, production of agricultural products and pest control requires use of different pesticides in the area. Information on industrial and agricultural pollution has not been clearly identified in Zambia, and little attention has been paid to pollution control and possible impact of metals, pesticides, and other persistent compounds in the environment. The objective of this study was to introduce and to evaluate a few methodologies based on in situ bioassays for environmental assessment to promote sustainable and environmentally sound water resource management of the Kafue River. The results show that caged threespot tilapia exposed downstream of industrial points sources rapidly bioaccumulate several trace elements, i.e., Cd, Co, Cu, Cr, Ni. These elements also occurred in much higher concentrations in water samples downstream of the industrial area compared with a locality upstream. Furthermore, the use of a semipermeable membrane device (SPMD) for passive absorption of lipophilic pollutants in the water showed relatively high concentration of several pesticides, i.e., DDT with major metabolites, PCB, and dieldrin. The present study shows that only 2 weeks of in situ studies in waters contaminated by pollutants affects in situ exposed fish and that the correlation between water and tissue concentrations was relatively good. Both trace elements and persistent organic pollutants occurred in such high concentrations that they must be considered from ecotoxicological aspects and may affect aquatic animal health.
Benzo[a]pyrene Toxicokinetics in Rainbow Trout (Oncorhynchus mykiss) Acclimated to Different Salinities by J. M. Seubert; C. J. Kennedy (pp. 342-349).
The effects of environmental salinity on the distribution, metabolism, and elimination of benzo[a]pyrene (B[a]P) were examined in mature rainbow trout. Trout acclimated to either fresh water (0 ppt, FW) or sea water (20 ppt, SW) for 3 weeks received a single 10 mg/kg intra-arterial injection of [3H]-benzo[a]pyrene (B[a]P) at their acclimation salinity or when subjected to an acute salinity change. Statistically significant differences in the percent body burden of B[a]P-derived radioactivity in various tissues were seen between fish in FW versus SW. Significant differences in the distribution of B[a]P and its metabolites were also noted when fish were subjected to an acute salinity change after chemical injection. Modulation of B[a]P metabolism by environmental salinity included: (1) significant differences in the proportions of Phase I metabolites in the bile of FW- (2.3%) versus SW-acclimated (14.1%) fish, and (2) alterations in the accumulations of specific metabolites (predominantly t-9, 10-dihydrodiol-B[a]P in FW fish, and 3-hydroxy-B[a]P in SW fish). The percentages of the [3H]-B[a]P dose eliminated by 48 h was similar in FW and SW fish, but decreased in fish subjected to an acute salinity change (FW 98.8% eliminated, FW:SW 90.4%, SW 98.1%, and SW:FW 93.1%). Pharmacokinetic modeling confirmed that acute salinity changes can result in longer terminal half-lives and slower total body clearances of B[a]P.
Effect of Maintaining Rainbow Trout in Creosote Microcosms on Lens Optical Properties and Liver 7-Ethoxyresorufin-O-Deethylase (EROD) Activity by J. J. Whyte; K. L. Herbert; N. A. Karrow; D. G. Dixon; J. G. Sivak; N. C. Bols (pp. 350-356).
Previously, exposure of fish to polycyclic aromatic hydrocarbons (PAHs) in both field and laboratory settings has been associated with eye damage, but this has only been expressed qualitatively. In this study, an automated scanning laser system has been employed to quantitatively evaluate changes in lens optical quality in rainbow trout (Oncorhynchus mykiss) following their in vivo exposure to creosote, which is a complex mixture with many PAHs. Rainbow trout were placed in 12,000-L outdoor microcosms dosed with 0, 3, or 10 μl/L liquid creosote for a 28-day period. Collected fish were examined for changes in focal length variability (FLV), lens size, and weight. These measurements were compared with induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic and water concentrations of priority pollutant PAHs. The optical quality of rainbow trout lenses was significantly reduced following creosote exposure, as indicated by increased FLV. Lens damage was significantly related to hepatic EROD activity, and both effects rose with creosote dose. Analytical measurements of microcosm water indicated elevated concentrations of PAHs in creosote-dosed ponds, including compounds capable of inducing rainbow trout EROD activity in vitro. Hepatic concentrations of PAHs were low and not related to creosote dose, likely due to rapid metabolism and elimination. This study demonstrates for the first time employment of a highly sensitive and quantitative technique to measure lens damage in fish exposed to contaminants in situ. The relationship between this effect and hepatic CYP1A activity may suggest a mechanistic linkage, which could lead to the use of EROD activity as an indicator of toxic effect rather than just chemical exposure.
Effects of Chronic Dietary Cadmium on Hepatic Glutathione Levels and Glutathione Peroxidase Activity in Starlings (Sturnus vulgaris) by L. Congiu; M. Chicca; A. Pilastro; M. Turchetto; L. Tallandini (pp. 357-361).
The effects of chronic exposure to dietary cadmium on the levels of hepatic glutathione (GSH) and on the activity of the glutathione peroxidase enzymes (GSH-Px) were studied for the first time in starlings (Sturnus vulgaris). Thirty-three individuals (17 females and 16 males) were divided into three groups: One represented the untreated control and two were respectively fed with diets containing 10 and 50 ppm cadmium chloride (CdCl2). The total duration of treatment was 22 weeks. The three groups respectively accumulated mean hepatic Cd residues of 2.29, 75.71, and 208.49 ppm. Hepatic GSH increased in the treated groups respectively 24% and 52% in comparison to controls. Total GSH-Px activity in the liver was inhibited in the group fed with 50 ppm, due to inhibition of the selenium-dependent fraction of the enzyme, while the selenium-independent fraction did not change significantly. During the treatment, after 14 weeks of exposure to cadmium, the 50 ppm–treated group showed a 47% decrease of the activity of the selenium-dependent GSH-Px and a 50% increase of the somatic liver index in comparison with controls.
Polychlorinated Dibenzo-p-Dioxins (PCDDs), Dibenzofurans (PCDFs), Biphenyls (PCBs), and Organochlorine Pesticides in Yellow-Blotched Map Turtle from the Pascagoula River Basin, Mississippi, USA by K. Kannan; M. Ueda; J. A. Shelby; M. T. Mendonca; M. Kawano; M. Matsuda; T. Wakimoto; J. P. Giesy (pp. 362-370).
Concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs), -biphenyls (PCBs), and organochlorine pesticides were measured in tissues of map turtles collected from two locations in the Pascagoula River drainage of Mississippi, USA. PCBs were most predominant among the organochlorines with a concentration of up to 99 ng/g, wet weight (580 ng/g, lipid weight) in livers. The greatest concentration of PCDDs/DFs of 1.1 pg/g, wet weight (15.76 pg/g, lipid weight) was found in the liver of a male turtle. The measured concentrations of organochlorines were less than those reported for turtles from the Great Lakes Basin and upper St. Lawrence River. PCBs contributed 90–99% of the total estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs). Particularly, PCB congeners 105, 118, and 156 accounted for 68–80% of the estimated toxic potency of PCBs in turtles.
Minimal Endocrine Alterations in Rodents After Consumption of Lake Trout (Salvelinus namaycush) by S. L. Gerstenberger; I. Heimler; R. Smies; R. J. Hutz; A. K. Dasmahapatra; V. Tripoli; J. A. Dellinger (pp. 371-376).
Polychlorinated biphenyls (PCBs) and dioxins are known to cause disruptions in circulating hormone concentrations, which may influence fertility and normal fetal development. Structure activity relationships have been determined for individual congeners, but it is unclear what impacts occur due to exposure to complex mixtures of chemicals found in the environment. Most laboratory studies of PCB exposure have used commercial mixtures in high doses, which may not be representative of environmental concentrations of individual congeners, nor accurately represent complex interactions of multiple contaminants. The present study investigated endocrine alterations in rats associated with the consumption of lake trout collected from three specific locations in the Great Lakes. Composite fish samples were analyzed for PCBs, organochlorines, and mercury and ranged from 415 ppb to 1,275 ppb for individual contaminants. Fillet composites were fed to timed-pregnant Long-Evans rats as 30% of their diet. Concentrations of total thyroxine and estrogen were not significantly different in offspring of dosed dams from that of controls. However, aromatase activity was lowered in all dosed groups as compared with controls. This may represent a lowered expression of the CYP 19 gene in exposed rats or may be due to the presence of one or more substances in the contaminants that are capable of altering the affinity of the aromatase enzyme for its normal endogenous substrate. It is also possible that the number of maturing follicles in the lake trout–fed rats may be fewer than controls, which would result in an overall reduction in the enzyme activity. Data regarding the endocrine effects of environmental contaminant mixtures found in fish from the Great Lakes Basin are still controversial. Additionally, information is scarce with respect to the F1 generation of laboratory animals following environmental maternal exposures, therefore, we investigated the reproductive-endocrine alterations in rat offspring associated with the consumption of lake trout (Salvelinus namaycush) collected from three areas in the Great Lakes.
Exposure of the U.S. Population Aged 6 Years and Older to Cadmium: 1988–1994 by D. C. Paschal; V. Burt; S. P. Caudill; E. W. Gunter; J. L. Pirkle; E. J. Sampson; D. T. Miller; R. J. Jackson (pp. 377-383).
Cadmium was measured in urine specimens from 22,162 participants in the Third National Health and Nutrition Examination Survey (NHANES III 1988–1994). Urine cadmium, expressed either as uncorrected (μg/L) or creatinine corrected (μg/g creatinine) increased with age and with smoking. The arithmetic mean value for urine cadmium in the U.S. population was 0.57 μg/L or 0.48 μg/g creatinine. Based on our estimates, about 2.3% of the U.S. population have urine cadmium concentrations greater than 2 μg/g creatinine, and 0.2% have concentrations greater than 5 μg/g creatinine, the current World Health Organization health-based exposure limit.
Normal Values for Arsenic and Selenium Concentrations in Human Lung Tissue by T. Kraus; G. Quidenus; K. H. Schaller (pp. 384-389).
Normal values and ranges were determined for arsenic and selenium concentrations in lung and hilus tissue. The study group consisted of 50 deceased persons, who were examined by autopsy at the Institute for Pathology of the University of Erlangen-Nuremberg. Taking into consideration topographic-anatomical criteria, samples were taken of each lung lobe and the hilar lymph nodes. The dried tissue was analyzed using by means of hydride atomic absorption spectrometry after wet-oxidative digestion. Normal values ranged for the arsenic concentrations from <1–74 ng/g dry weight and for the selenium concentrations from <3–574 ng/g dry weight. Arsenic was found to accumulate in the hilus tissue, whereas selenium did not. Considerable intraindividual and interindividual variation was found for both arsenic and selenium. There were no statistically significant differences regarding age, smoking habits, and lung diseases. Lung tissue samples from three deceased persons from Houston, Texas, contained lower arsenic concentrations and somewhat higher levels of selenium compared to the German autopsies; these levels were, however, still within the indicated normal ranges. The following conclusions can be drawn from the results available at present: Intraindividual and interindividual variation is high for the arsenic and selenium concentrations in human lung tissue, so that only relatively wide normal ranges can be given for the general population. Smoking habits, age, and lung diseases do not seem to affect the indicated normal ranges. Postmortem determination of arsenic and selenium concentrations in human lung tissue can provide important information on former occupational or environmental exposure.
Herbicide Spray Drift Odor: Measurement and Toxicological Significance by J. N. Brown; S. R. Gooneratne; R. B. Chapman (pp. 390-397).
The toxicological significance of exposure of members of the public to spray drift odors of four herbicide formulations (three 2,4-dichlorophenoxyacetic [2,4-D] acid derivatives and one MCPA [4-methyl-2-chlorophenoxyacetic acid] derivative) has been studied using a combination of novel odor measurement and classic residue analysis techniques. The mean odor concentrations, generated during the spraying of the commercial herbicide formulations under simulated aerial application conditions, were about twofold higher for 2,4-D ethylhexyl ester (22,500 OUc/m3) and MCPA (30,100 OUc/m3) than for 2,4-D butyl ester (12,400 OUc/m3) and 2,4-D amine (11,800 OUc/m3). Detailed investigations determined that the odors are due to trace manufacturing impurities and additives in the commercial formulations, whereas the herbicide active ingredients are odorless. Measured airborne herbicide active ingredient concentrations under the simulated aerial application conditions were all below their respective occupational safety and health TLV-TWA values, indicating that exposures of toxicological significance as a result of spray drift are unlikely.
Captan Fungicide Exposures of Strawberry Harvesters Using THPI as a Urinary Biomarker by R. I. Krieger; T. M. Dinoff (pp. 398-403).
Clothing affords harvesters considerable protection against the elements and can retain substantial amounts of pesticide residue from treated crops. Normal work clothing of female harvesters was supplemented with rubber latex gloves and facial scarves to determine whether those measures reduced exposure. Captan fungicide exposures in female strawberry harvesters were assessed by determining urine clearance rates of tetrahydrophalimide (THPI). Clean rubber gloves were supplied to the 41 harvesters for the 3 days of the study period in October 1995. The workers were divided into two groups consisting of either bare-handed or gloved workers, and 24-h urine specimens were collected each day. Female harvesters who worked bare-handed cleared 5.3 μg captan equivalents as THPI with a range of 0.4 to 13.8 μg/person/day. Harvesters who worked wearing rubber latex gloves cleared only 2.0 μg captan equivalents with a range of 0.9 to 4.3 μg/person/day. In this case clean rubber latex gloves reduced absorbed dose by 38%, compared to the dose absorbed by bare-handed workers. These results additionally indicate that when a pesticide is avidly retained by rubber latex gloves and not readily absorbed dermally as captan, estimates of absorbed dose based on passive dosimetry data may be less reliable than exposure estimates derived from urine biomonitoring.