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Archives of Environmental Contamination and Toxicology (v.33, #3)
PCDD/Fs in Soil Samples Collected in the Vicinity of a Municipal Solid Waste Incinerator: Human Health Risks by M. Schuhmacher; A. Xifró; J. M. Llobet; H. A. M. de Kok; J. L. Domingo (pp. 239-246).
The concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were determined in soil samples taken from 24 sites in the vicinity of a municipal solid waste incinerator (Montcada, Barcelona, Spain). Samples were collected within a radius of 3 km in each of the three main directions of the wind rose in that area. Hepta- and octa-CDDs were the predominant congeners and contributors to TEQ. PCDD/F levels ranged from 0.30 to 44.26 ng TEQ/kg (dry matter), with median and mean values of 3.52 and 6.91 ng TEQ/kg, respectively. The highest and lowest PCDD/F concentrations were found at 750 m (44.26 ng TEQ/kg) and 3000 m (0.30 ng TEQ/kg) from the stack, while the PCDD/PCDF ratio was 1.78. The health risk analysis of the data shows that the PCDD/F intake from soils is substantially lower than the tolerable daily intake for toxicologic (other than cancer) effects of PCDD/Fs.
Isoxaben Soil Biodegradation in Pear Tree Orchard After Repeated High Dose Application by J. Rouchaud; O. Neus; R. Bulcke; D. Callens; T. Dekkers (pp. 247-251).
During the past nine years, each of the plots of a pear tree orchard were treated annually with the same herbicide treatment. The following herbicide treatments were compared, each being made by application of a mixture of two or three herbicides: 1a, no herbicide at all, weeds being hoed (control 1a); 2, diuron + paraquat 3 + 1 kg/ha; 3, simazine + paraquat 2 + 1 kg/ha; 4, isoxaben + diuron + paraquat 0.5 + 1.6 + 1 kg/ha; and 5, isoxaben + simazine + paraquat 0.5 + 1.25 + 1 kg/ha. In March 1996, one year after the final orchard herbicide treatment, isoxaben could not be detected in the soils of any field plots; isoxaben was incorporated at 0.74 mg/kg in the loamy soils sampled separately in each of the field plots, and the soils were incubated in the laboratory. Isoxaben soil half-lives were 92 days in the soils treated previously with herbicide treatments 1a, 2, or 3 and 42 days in the soils treated with herbicide treatments 4 and 5. The repeated isoxaben treatments applied in the past thus enhanced the isoxaben soil biodegradation; diuron, simazine, and paraquat had no influence on this rate enhancement. On the other hand, herbicide treatments 4 and 5 were applied in the orchard in April 1996 on the corresponding plots treated in this manner for the last nine years. Isoxaben + paraquat 0.5 + 1 kg/ha was applied simultaneously on other plots (control 1b) not treated in the past with isoxaben. During the growth season in the orchard, the isoxaben soil half-lives in the control plots 1b was 101 days, and 41 days in the plots where herbicide treatments 4 or 5 were applied.
Investigations into Using the Nematode Caenorhabditis elegans for Municipal and Industrial Wastewater Toxicity Testing by D. R. Hitchcock; M. C. Black; P. L. Williams (pp. 252-260).
This investigative study assesses the ease and usefulness of the nematode Caenorhabditis elegans for identifying contributors to effluent toxicity within an industrial and municipal wastewater treatment plant (WWTP) system. Several different types of industries, including fiberglass manufacturing, paper packaging, and yarn dyeing, discharge effluent into the municipal wastewater treatment plant, which in turn discharges into a local creek. A major objective of this study was to identify primary sources of toxicity throughout the system with a nematode toxicity test. Twenty-four-hour composite water samples were taken periodically over a ten-month period at five strategic points within the system: (1) at the point of discharge at each of the three industries, (2) at the combined industrial influent of the wastewater treatment plant, (3) at the effluent of the WWTP, (4) upstream of the WWTP discharge, and (5) downstream of the WWTP discharge. Samples were analyzed for basic water chemistry, and each sample was tested for whole effluent toxicity using a 72-h nematode test with mortality as the end point. Results suggest that interactions between the wastewaters of certain industries may increase the overall nematode toxicity in the wastewater treatment facility's composite influent and effluent. Nematode mortality trends indicate relatively high toxicity levels in wastewater entering the WWTP from contributing industries. High WWTP influent toxicity may potentially be due to varying flow rate ratios of industrial discharges, release of varying toxic constituents in wastewaters, and toxic interactions between chemical constituents of industrial wastewaters. The evaluation of toxicity within the treatment system may pinpoint locations where pollution prevention strategies may be implemented to reduce overall toxicity at the point of discharge.
Chronic Toxicity of Atrazine to Sago Pondweed at a Range of Salinities: Implications for Criteria Development and Ecological Risk by L. W. Hall, Jr.; R. D. Anderson; M. S. Ailstock (pp. 261-267).
The objective of this study was to conduct a series of 28-d partial life-cycle atrazine subchronic toxicity tests with sago pondweed, Potamogeton pectinatus, at salinities of 1, 6, and 12 ppt. These data will be used for development of a chronic estuarine criterion for atrazine in Maryland waters of Chesapeake Bay and to determine possible ecological risk for a sensitive nontarget species. The three endpoints used for this submerged aquatic macrophyte were final wet weight, final dry weight, and final number of rhizome tips at the termination of the 28-d test. Dry weight was determined to be the most sensitive endpoint. Chronic values from a one-way ANOVA using dry weight were 21.2, 21.2, and 10.6 μg/L at salinities of 1, 6, and 12 ppt, respectively. Chronic values using wet weight were 21.2 μg/L at all three salinities. A chronic value of 94.9 μg/L was reported at all three salinities using rhizome tips as the endpoint. A two-way ANOVA was also used for analysis of data to increase the power of detecting differences among treatments and assess salinity interaction. The salinity effects were averaged in the two-way ANOVA. Both rhizome tips and dry weight were used in the two-way ANOVA; wet weight did not satisfy the equal variance assumption. The chronic value for rhizome tips was 94.9 μg/L atrazine, which is the same value reported from the one-way ANOVA. There was no salinity effect and no interaction between salinity and atrazine concentration. The chronic value determined from the two-way ANOVA using dry weight was 5.3 μg/L; there was a salinity effect but no significant salinity/atrazine concentration interaction. Salinity was not reported to effect either dry weight or rhizome tips after 28-d exposures in the controls but wet weight was significantly lower at 12 ppt when compared with 1 and 6 ppt. Ecological risk to sago pondweed from atrazine exposure was judged to be low based on recent exposure data from the mainstem, tributaries, and streams in Chesapeake Bay.
Effects of a Crude Oil Spill on the Benthic Invertebrate Community in the Gasconade River, Missouri by B. C. Poulton; S. E. Finger; S. A. Humphrey (pp. 268-276).
Effects of a 3.3-million–L crude oil spill on the benthic macroinvertebrate community of the Gasconade River, a large river in Missouri, were evaluated by comparing several macroinvertebrate community indices in riffle and backwater habitats above and below the spill. Concentrations of total petroleum hydrocarbons (TPH) in sediments decreased dramatically in riffle habitats within 6 months of the spill, but elevated hydrocarbon levels (TPH = 80–270 μg/g) were still present in backwater habitats at the end of the study. Correspondingly, riffle macroinvertebrate communities recovered rapidly, but overall benthic diversity continued to be reduced in backwater areas until the end of the study 18 months after the spill. In addition, statistical analysis of benthic functional feeding groups revealed that both scrapers and shredders were reduced in backwater habitats below the oil spill. Decreased abundance of shredders and scrapers in these habitats is likely caused by oil contamination of aquatic sediments and associated organic matter required by these groups for food and substrate. Results of this study suggest that the persistence of oil in backwater habitats has a negative effect on the benthic community in large rivers.
Long-Term Recovery of Macrobenthos and Fish Assemblages After Water Pollution Abatement Measures in the River Petite Baïse (France) by F. Dauba; S. Lek; S. Mastrorillo; G. H. Copp (pp. 277-285).
Riverine ecosystems are subject to a large variety of man-made influences, and in recent years a new public awareness of the need to protect rivers has emerged within the industrialized world. The present study focuses on the effect of abatement of pollution from one factory on the recovery of fish and macroinvertebrate species richness in the River Petite Baïse over a 20-year period (1973–1993). Until 1973, the Petite Baïse (75 km in length) received not only factory waste (nitrogenous rich effluents) but also the untreated sewage of many villages and agricultural runoff from the river's catchment. In 1970, macroinvertebrates and fishes were absent in the river despite having initially been classified as of the barbel Barbus barbus zone, and extensive efforts were made by the factory to reduce pollution to allow the riverine community to recover. Regular surveys between 1973 and 1993 revealed a progressive improvement in water quality and the recolonization of the river by macrobenthic and fish populations. Macrobenthic fauna species richness gradually increased from zero in 1970 to level 8 or 9 in 1993 (Verneaux and Tuffery method), reflecting improvements in river water quality. Fish were not observed until 40 km downstream of the factory in 1978, 16 km in 1980, and approximately 5 km by 1990. Fish species richness increased from five in 1978 (barbel, chub Leuciscus cephalus, stone loach Barbatula barbatula, minnow Phoxinus phoxinus, gudgeon Gobio gobio) to eight in 1990 (the carnivorous brown trout Salmo fario, the omnivorous chub, and six benthophagous fishes: gudgeon, barbel, minnow, stone loach, sofie Chondrostoma toxostoma, carp Cyprinus carpio). Fish biomass 45 km downstream the factory increased from 1 g/m2 in 1978 to more than 5 g/m2 by 1990. Recolonization of the river, in particular those areas furthest downstream from the factory, occurred as a result of reductions in the nitrogen inputs emanating from the factory.
Effect of Glyphosate on the Development of Pseudosuccinea columella Snails by T. M. Tate; J. O. Spurlock; F. A. Christian (pp. 286-289).
Glyphosate (Roundup) is one of the most commonly used broad-spectrum herbicides with little to no hazard to animals, man, or the environment. Due to its widespread use, there is continuous contamination of the environment in both soil and water with this herbicide. There is a paucity of long-term exposure studies with sublethal concentrations of glyphosate on aquatic snails. This study was developed to determine the effects of sublethal concentrations of glyphosate on development and survival of Pseudosuccinea columella (intermediate snail host of Fasciola hepatica). This was assessed by continuously exposing three successive generations of snails to varying concentrations (0.1–10 mg/L) of glyphosate. Glyphosate had little effect on the first- and second-generation snails. However, third-generation snail embryos exposed to 1.0 mg/L glyphosate developed much faster than other embryos exposed to 0.1 mg/L, 10 mg/L, and 0 mg/L (control). Hatching was inhibited at 10 mg/L and inhibited slightly at 0.1 mg/L. The egg-laying capacity was increased in snails exposed to 0.1 and 10 mg/L. Abnormalities and polyembryony were observed in snails exposed to 0.1 and 10 mg/L. These results indicate that glyphosate does affect snail reproduction and development. This, in turn, could possibly have an effect on the population dynamics of F. hepatica, which could result in increased infections in animals, including man.
Effects of Nitrite Exposure on Acid–Base Balance, Respiratory Protein, and Ion Concentrations of Giant Freshwater Prawn Macrobrachium rosenbergii at Low pH by J.-C. Chen; Y. Lee (pp. 290-297).
Macrobrachium rosenbergii that had been exposed individually for 24 h to 0 (control), 2, 5, 10 mg/L nitrite-N (nitrite as nitrogen) at 4.3 and 7.7 pH levels were examined for hemolymph nitrite-N, oxyhemocyanin, protein, acid–base balance, ion concentrations, and ammonia-N (ammonia as nitrogen) excretion. Hemolymph oxyhemocyanin, protein, pH, HCO3 − , TCO2, osmolality, and ion concentrations were inversely related to ambient nitrite-N concentration and were lower at pH 4.3. However, hemolymph nitrite-N, PO2 and PCO2 levels, and ammonia-N excretion were directly related to ambient nitrite-N, and were higher at pH 4.3. Ambient nitrite-N and pH level interacted to cause changes in hemolymph nitrite-N, oxyhemocyanin, protein, PO2, and pH levels. It is concluded that for M. rosenbergii following nitrite exposure, the incorporated nitrite causes a decrease of pH and an increase of PO2 in the hemolymph where it reduces oxyhemocyanin level; disturbs nitrogen excretion, ion regulation, and respiratory gas exchange; and may lead to a decrease of oxygen-carrying capacity, which are affected more at low pH.
Concentration-Dependent Changes of PCB Patterns in Fish-Eating Mammals: Structural Evidence for Induction of Cytochrome P450 by J. P. Boon; J. van der Meer; C. R. Allchin; R. J. Law; J. Klungsøyr; P. E. G. Leonards; H. Spliid; E. Storr-Hansen; C. Mckenzie; D. E. Wells (pp. 298-311).
Data sets on CB concentrations in fish-eating mammals from five laboratories were combined to test and refine a pharmacokinetic model. Clear differences in PCB patterns were observed between species. The ability to metabolize chlorobiphenyl (CB) congeners with vicinal H-atoms only in the ortho- and meta-positions and with one ortho-chlorine substituent generally increased in the order otter < cetaceans (harbor porpoise, common dolphin) < phocid seals (harbor and grey seal), but the metabolism of congeners with vicinal H-atoms in the meta- and para-positions and with two ortho-chlorines increased in the order cetaceans < seals < otter. Both categories of congeners are probably metabolized by different families of cytochrome P450 (1A and 2B) of which levels apparently differed between the cetaceans, the pinnipeds, and the otter. Within-species CB patterns differed in a concentration-dependent manner. The induction of cytochrome P450 enzymes offers the most likely explanation for this phenomenon, but starvation could have a similar effect on occasion.
Mercury Accumulation in Mink Fed Fish Collected from Streams on the Oak Ridge Reservation by R. S. Halbrook; L. A. Lewis; R. I. Aulerich; S. J. Bursian (pp. 312-316).
This study evaluates effects of feeding mercury (Hg) contaminated fish collected from streams on the Oak Ridge Reservation (ORR) on mink. Diets composed of 25, 50, or 75% fish collected from streams on the ORR were fed to mink beginning 3 months prior to breeding and ending 6 weeks following whelping. Mercury concentrations in diets, tissues of adult mink and their offspring, and physiological and reproductive effects were recorded and compared to concentrations and effects observed in mink fed diets composed of 75% fish collected from the Clinch River above the ORR or from the ocean. Mercury concentrations in prepared diets and in tissues of adult mink and their offspring increased progressively with increased percentage of ORR fish in the diets. Female mink fed diets containing 75% ORR fish had reduced body weight and a decreased number of kits compared to those fed diets containing 75% fish collected above the ORR or from the ocean. However, based on previously reported Hg concentrations associated with adverse effects in mink, the observed adverse effects are not thought to result from exposure to Hg.
Determination of Polycyclic Aromatic Hydrocarbons (PAH) and Their Metabolites in Blood, Feces, and Urine of Rats Orally Exposed to PAH Contaminated Soils by F. J. van Schooten; E. J. C. Moonen; L. van der Wal; P. Levels; J. C. S. Kleinjans (pp. 317-322).
Polycyclic aromatic hydrocarbons (PAH) have become an ubiquitous upper soil component as a consequence of industrialization involving a multitude of combustion processes. Ingestion of PAH contaminated soil is considered to be a major exposure route, specifically for small children living on these soils. Health risk assessment is based on extrapolations from data obtained via studies performed with pure chemicals. Additionally it is assumed that after oral intake all PAH present in the soil will be absorbed by the human body. Interactions with the soil matrix, however, may modulate the bioavailability of PAH. In this study, we examined the absorption and excretion of PAH in rats orally exposed either to industrially contaminated soils or pure model compounds as anthracene, pyrene and benzo(a)pyrene (B[a]P). The model compounds and the metabolites, 1-hydroxypyrene (1-OH-pyrene) and 3-hydroxybenzo(a)pyrene (3-OH-B[a]P), were measured in blood, feces or urine by means of HPLC with fluorescence detection. Because of rapid biotransformation only minimal levels of unmetabolized anthracene, pyrene and B[a]P in blood could be detected. The pharmacokinetic parameters were nonlinear and suggestive of enterohepatic cycling. Only low levels of the compounds were excreted unchanged in feces whereas the levels of the metabolites were considerably higher in feces and urine. These results indicate that the dosed PAH are largely absorbed by the gastrointestinal tract, subsequently metabolized and excreted as metabolites via urine and feces. Significant differences between the soil-treated group and the pure mixture-treated group could be observed; the soil-treated group showed higher fecal excretion of unchanged pyrene (0.5 versus 0.2% of the original dose) and B[a]P (1 versus 0.3%), lower excretion of 1-OH-pyrene in feces (5.1 versus 17.0%), and lower excretion of 1-OH-pyrene in urine (0.2 versus 3.4%). The fecal excretion of 3-OH-B[a]P between the two groups was similar (8.8 versus 8.8%). These results suggest that the soil matrix is capable of reducing the absorption of at least pyrene. Therefore, exposure risk assessment models assuming complete bioavailability of soilmatrix-bound PAH probably overestimate the endogenous dose.
Applicability of Aspecific Noninvasive Methods for Biomonitoring of Occupational Exposure to Deltamethrin: Preliminary Study Using an Animal Model by M. Moretti; M. Villarini; G. Scassellati-Sforzolini; R. Pasquini.; S. Monarca (pp. 323-328).
Deltamethrin (CAS registry No. 52918-63-5), a synthetic dibromo-pyrethroid insecticide is highly effective against a broad spectrum of insects, and is widely used on crops and in public health programs. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of the present study was to analyze previously demonstrated metabolic changes using aspecific noninvasive methods in rats which are potentially applicable for monitoring occupational exposure. Since human exposure to pesticides occurs not only to active principles but to all chemicals present in a commercial formulation, we tested both the pure compound and a deltamethrin-based commercial formulation. Groups of rats were treated, i.p., consecutively for 7 days. The daily doses tested were 5 and 10 mg/kg body weight for pure deltamethrin, corresponding to volumes of 178.57 and 377.14 μl/kg body weight for the commercial formulation (containing 2.8% deltamethrin). Urine was analyzed for mutagenic metabolites, thioethers, and D-glucaric acid content. Faeces extracts were tested for mutagenicity. Results show that DGA urinary excretion values did not mirror the phase I enzyme induction capability of the insecticide. Results obtained for urinary thioethers do not agree completely with those obtained on the influence of deltamethrin on glutathione S-transferase activity in rat liver. In fact, after administration of the deltamethrin commercial formulation, highest thioether excretion values were obtained during the treatment time for treated animals, as compared to controls. The mean values (±SEM) of thioether excretion were 0.033 ± 0.002 μmole -SH/24 h for control animals, 0.122 ± 0.004 and 0.185 ± 0.025 for the two treatment groups. Thence, thioether determination in urine samples seems to be a suitable aspecific noninvasive method for assessing exposure to deltamethrin-based formulations, particularly those containing xylene and mesitylene as solvents, as in the tested formulation. Negative or toxic results obtained in the urinary and faecal mutagenicity test seem to exclude the formation and excretion of mutagenic metabolites following treatment with deltamethrin.
Biological Monitoring of the Fungicide Epoxiconazol During Application by A. Oestreich; P. Schmid; C. Schlatter (pp. 329-335).
A method was developed for the biological monitoring of the fungicide epoxiconazol (Opus®; BASF). Comparison of the urine levels of a hydroxylated metabolite after dermal application to the levels after oral intake revealed a dermal absorption of 1–2.5% of the dose. In a field study with 10 applicators a dermal exposure ranging between 60 and 10,000 μg/person/day was determined from the urine levels of a hydroxylated metabolite; the contribution of the inhalation exposure was found to be negligible. From these data an incorporation of 1 to 100 μg epoxiconazol/person/day could be derived. The measured exposure was compared to two commonly used exposure models. The model calculation resulted in a dermal exposure of 555 μg/person/day (German BBA model) and 2115 μg/person/day (British POEM), respectively, which is in accordance with the actually measured exposure.
Gastric Cancer Mortality and Drinking Water Qualities in Taiwan by C.-Y. Yang; H.-F. Chiu; J.-F. Chiu; M.-F. Cheng; W.-Y. Kao (pp. 336-340).
The possible association between the risk of gastric cancer and nitrate and hardness in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. Data on gastric cancer deaths among eligible residents in Taiwan from 1987 through 1991 (6,766 cases) were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes (6,766 controls) and were matched individually to the cases by sex, year of birth, and year of death. Data on nitrate–nitrogen (NO3–N) and hardness levels in drinking water throughout Taiwan were collected from the Taiwan Water Supply Corporation (TWSC). The municipality of residence for cases and controls was assumed to be the source of the subject's nitrate and hardness exposure via drinking water. There was no difference in gastric cancer rates between the groups with different levels of nitrate. The odds ratios (95% confidence interval) for death from gastric cancer was 0.95 (0.87–1.03) for the group with water nitrate levels between 0.23 and 0.44 mg/L, and 1.02 (0.93–1.11) for the group with nitrate levels greater than 0.45 mg/L. However, the results show a significant negative relationship between drinking water hardness and gastric cancer mortality. Odds ratios were 1.16 (1.07–1.26) and 1.65 (1.52–1.79), respectively, for exposure to moderately hard water and soft water compared with the use of hard water. This is an important finding for the Taiwan water industry and human health risk.