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Archives of Environmental Contamination and Toxicology (v.37, #3)
Oxime Reactivation of RBC Acetylcholinesterases for Biomonitoring by M. E. Hansen; B. W. Wilson (pp. 283-289).
A low-variability method to reactivate blood cholinesterases (ChEs) after prior exposure of mammals, including humans, to ChE-inhibiting organophosphate esters (OPs) is presented. A concentration of 10 mM pyridine 2-aldoxime methochloride (2-PAM Cl) was incubated with intact red blood cells (RBCs) and assayed virtually free of interfering oxime and hemoglobin (Hb). Variability was decreased by reducing the number of washing steps and sedimenting RBC ghosts through a 7% sucrose cushion. Statistically significant detections of reactivations as low as 5% with average “false positives” of 3.8% were achieved. Relative rates and extent of reactivation after OP treatment of rabbit RBC AChE in vitro were of the order dimethyl- (DDVP) > diethyl- (ethyl paraoxon) >, diisopropyl-substituted (diisopropyl fluorophosphate; DFP) OPs. Rabbit RBC AChE was reactivatable for up to 60 h following dermal exposure to ethyl parathion and reactivatable for only 12 to 24 h following exposure to methyl parathion. Reactivation of plasma ChEs with 0.1 mM 2-PAM Cl in the same animals was achievable for only 12 to 24 h after ethyl parathion and for only 1 to 4 h after methyl parathion.
Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans in Storm Water Outfalls Adjacent to Urban Areas and Petroleum Refineries in San Francisco Bay, California by R. J. Wenning; D. B. Mathur; D. J. Paustenbach; M. J. Stephenson; S. Folwarkow; W. J. Luksemburg (pp. 290-302).
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in storm water collected from 15 outfalls in San Francisco Bay, California, considered representative of areas located adjacent to petroleum refineries and mixed urban/commercial/residential land uses. Storm water sampling was conducted hourly over a 12-h period at two outfalls located near the city of Oakland and the suburban community of Benicia, which represent urban and mixed urban/light industrial land uses, respectively. Sampling was conducted hourly to determine temporal changes in the concentrations and distributions of PCDD/Fs during the first major rainstorm event of the 1995/96 winter season. In addition, storm water sampling was conducted in December 1995 and February/April 1996 at six publicly owned treatment work (POTW) outfalls located adjacent to developed, undeveloped, mixed residential/commercial, and industrial lands. Storm water sampling also was conducted at five outfalls located adjacent to petroleum refineries. The sampling results were used to examine changes in PCDD/F loadings to San Francisco Bay at the onset and midway through the winter rainy season and to characterize differences in PCDD/F concentrations, if any, between refinery and nonrefinery areas. The concentrations of tetra- through octa-chlorinated homologues and 2,3,7,8-substituted congeners were assayed in filtered storm water samples according to US EPA Method 1613A. Principal components analysis (PCA) was used as an exploratory technique to examine the similarities and differences in the distributions of PCDD/Fs in storm water from different outfalls. The sampling results showed few significant differences between storm water discharged from outfalls located in mixed urban/commercial/residential areas and outfalls located adjacent to petroleum refineries. The concentrations of 2,3,7,8-TCDD were below the analytical limits of detection in all storm water samples, with the exception of samples collected after the sixth hour of sampling at the Oakland outfall. Fingerprint patterns were generally dominated by the higher chlorinated PCDD/F congeners including OCDD, OCDF, and 1,2,3,4,6,7,8-HpCDD. Total TEQs were generally below US EPA ambient water quality criteria and aquatic ecotoxicology guideline values. The results of this study strongly suggest that discrete sampling of storm water outfalls is insufficient to characterize the concentrations and distributions of persistent hydrophobic contaminants such as PCDD/Fs. In addition to surface water runoff from the city of Oakland, other nonindustrialized urban locations may represent important sources of PCDD/Fs to San Francisco Bay.
Persistent Organochlorines in the Effluents from a Chlorine-Bleached Kraft Integrated Pulp and Paper Mill in Southeast Asia by N. T. Kim Oanh; B.-E. Bengtsson; L. Bætz Reutergårdh; D. T. Hoa; P.-A. Bergqvist; D. Broman; Y. Zebühr (pp. 303-309).
A bleached sulfate integrated pulp and paper mill producing printing and writing paper from mixed tropical hardwood and bamboo was studied. The mill uses a “conventional bleaching sequence,” C-E-H1-H2, with an average molecular chlorine consumption of 50 kg per ton of air-dried pulp (ADP). The content of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs) in the bleaching filtrate in terms of the nordic toxicity equivalent (N-TEQ) was 33.5, 1.15, 0.56, and 0.014 pg/L for the E, C, H1, and H2 bleaching stages, respectively. The corresponding PCDFs and PCDDs loads in ng/t ADP were in the same ranking, i.e., 670, 69, 11.2, and 0.28, respectively. The congener and isomeric pattern of PCDFs and PCDDs of the bleaching filtrate and the bleached pulp was found to be typical for the chlorine bleaching plant effluent. The obtained dioxin load formed in the mill is in agreement with Western studies for the given multiple chlorine of 0.21–0.23. The load is, however, lower than reported discharges from Scandinavian mills using 1980s bleaching technologies, but substantially higher than the discharges from mills with modern bleaching technologies. Modifications in the bleaching plant to reduce molecular chlorine use are necessary to reduce dioxin formation.
Sorption of Nine Pesticides to Three Aquatic Macrophytes by S. J. H. Crum; A. M. M. van Kammen-Polman; M. Leistra (pp. 310-316).
The sorption of nine pesticides to the aquatic macrophytes Chara globularis, Elodea nuttallii, and Lemna gibba was studied. A batch equilibrium method was used to study the sorption at five concentration levels to fresh shoots of the macrophytes. The results for the herbicides atrazine and linuron were described by nonlinear Freundlich equations, with Freundlich exponents ranging from 0.53 to 0.60. The results for the other compounds showed almost linear sorption isotherms, with Freundlich exponents ranging from 0.9 to 1.1. The highest sorption was measured for chlorpyrifos, with sorption coefficients ranging from 1,660 to 2,150 L/kg. Sorption coefficients for C. globularis tended to be lower than those for the other two macrophytes. Correlation (R2 = 0.80) was found for the relation between the sorption coefficient (Kd) of six pesticides and their solubility in water (S). The equation log Kd= 3.20 − 0.65 log S can be used for a first estimate of the sorption coefficient of a pesticide to aquatic macrophytes.
Polychlorinated Biphenyl- and Mercury-Associated Alterations on Benthic Invertebrate Community Structure in a Contaminated Salt Marsh in Southeast Georgia by M. T. Horne; N. J. Finley; M. D. Sprenger (pp. 317-325).
The community structure of a benthic macroinvertebrate assemblage in a contaminated salt marsh was evaluated as part of an ecological characterization of a former chloralkali production facility in Georgia. Sample locations were chosen based on a gradient of the primary contaminants of concern, total mercury and polychlorinated biphenyls (PCBs), primarily Aroclor 1268. Sediment concentrations of Aroclor 1268 ranged from 2.3 to 150 mg/kg dry weight, while mercury concentrations ranged from 15 to 170 mg/kg dry weight in the study area. Mercury and PCBs were determined to be co-located in the sediments. Total organic carbon composition of the sediments was negatively associated with PCB and mercury concentrations. A total of 29 benthic taxa was identified in 49 samples; replicate samples were taken at each of five sampling locations. Mean infaunal density across all sampling locations was estimated at approximately 61,000 to 234,000 organisms m−2. Overall, polychaetes comprised 57% of the infaunal community with Manayunkia aestuarina as the dominant species. Oligochaetes, nematodes, crustacea, insects, and gastropods comprised 23.0, 18.0, 1.0, 0.7, and 0.2% of the overall benthic community, respectively. Density estimates of individual species between sampling locations showed no consistent patterns in response to pollutants. However, an analysis of higher taxonomic levels revealed some general trends. In uncontaminated areas, the benthic community was dominated by nematodes and oligochaetes, whereas moderate to highly contaminated areas were dominated by polychaetes and a smaller percentage of oligochaetes and nematodes. A trophic analysis of the same data set revealed that the community shifted from an evenly distributed percentage of surface and subsurface feeders in the uncontaminated areas to a community dominated by surface feeders in the more contaminated locations. Carnivores comprised from 0.13 to 0.90% of the trophic structure, with the percentage of carnivores generally decreasing with increasing contamination. Mercury and PCBs were bioaccumulating in representative marsh benthic invertebrates, presenting a potential source of contaminants to marsh consumers. Tissue PCB and tissue mercury concentrations were positively related to sediment PCB and mercury concentrations, respectively. A standard 14-day toxicity test using the amphipod Leptocheirus plumulosus showed no acute toxicity across the sampling locations.
Comparing Metal Toxicity Among Daphnia magna Clones: An Approach Using Concentration-Time-Response Surfaces by Carlos Barata; Donald J. Baird; Scott J. Markich (pp. 326-331).
This study investigates the use of concentration-time-response surfaces as a tool to predict potential long-term effects of metals to Daphnia magna, using mortality as an endpoint. Specifically, concentration-time-response surfaces were determined for four D. magna clones exposed to four metals (Cd, Zn, Cu or U) in moderate-hard or hard synthetic freshwater for 24–96 h. Mortality data were loge transformed into probits and then regressed against the reciprocal of exposure time and concentration. The results obtained clearly showed that mortality was markedly affected at exposure periods longer than 48 h. Thus, an optimal exposure period of 72 h was selected to compare predicted lethality effects (LC) of different intensities (i.e., 10–50%) derived from concentration-time-response surfaces with measured chronic lethal levels obtained from the literature. Only the results of Cd and Cu show good agreement between predicted and measured chronic lethal concentration levels. The apparent disagreement observed for U could be attributed to differences in water quality, and hence, U bioavailability. The high levels of Zn toxicity observed in relation to the predicted values could indicate that chronic mortality of Zn is mediated by toxic anorexia. Overall, the results obtained show that concentration-time-response surfaces offered the potential to assess the effect of time on toxicity, which is desirable to credibly extrapolate from acute to chronic scenarios. Furthermore, by determining lower mortality thresholds (i.e., LC10) at different times, concentration-time-response surfaces were able to emulate the mode of action of the selected metals on chronic exposures. Therefore, the use of concentration-time-response surfaces has potential application in environmental risk assessment.
Tolerance to Zinc in Populations of the Earthworm Lumbricus rubellus from Uncontaminated and Metal-Contaminated Ecosystems by D. J. Spurgeon; S. P. Hopkin (pp. 332-337).
Zinc tolerance in Lumbricus rubellus populations from two metal-polluted (smelter and mine) sites was studied by comparing the effects of zinc with responses in a reference site strain. For the study, adult worms were collected directly from the field. Thus, no attempt was made to differentiate between tolerance resulting from population-level genetic adaptation or phenotypic plasticity in metal physiology. To compare relative sensitivity for zinc, worms from the three populations were exposed in laboratory tests. Effects on survival, weight change, cocoon production, and internal zinc levels were measured. Prior to exposure, it was anticipated that worms from the metal-contaminated sites would show substantially increased tolerance to zinc. This was not the case for all measured parameters. Thus, although differences in the shape of the dose-response relationships for survival and cocoon production were found, substantial variations in measured responses, effect concentrations, or zinc accumulation rates were not apparent. Overall, therefore, zinc tolerance is unlikely to be a major factor influencing the distribution of L. rubellus in contaminated regions.
Chronic Toxicity of Ammonia to New Zealand Freshwater Invertebrates: A Mesocosm Study by C. W. Hickey; L. A. Golding; M. L. Martin; G. F. Croker (pp. 338-351).
Freshwater macroinvertebrate communities were established within 12 artificial streams or “toroidal” mesocosms and exposed to three replicated concentrations of ammonia for 29 days at constant temperature (16°C) and pH (median 8.4). The criterion units (CU = measured [ammonia]/US EPA 1985 chronic criterion value) of total ammonia in the LOW, MED, and HIGH treatments were 2.0, 4.8, and 13 CUs respectively, and 1.9, 5.8, and 12 CUs for the unionized ammonia. Macroinvertebrates were tolerant of the ammonia exposures with no significant (p > 0.1) effect on taxa richness; number of taxa in the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT); or the quantitative macroinvertebrate community index (QMCI), a biotic index proposed for assessing effects of organic enrichment in New Zealand streams. Significant differences (p < 0.05) occurred for the mean abundance and the numbers of EPT individuals (QEPT), with the HIGH treatment significantly lower (−41%) than the control for both abundance and QEPT. Of the major species, only the mayflies Deleatidium sp. (Ephemeroptera: Leptophlebiidae) and Coloburiscus humeralis (Ephemeroptera: Oligoneuriidae) showed significant reductions in abundance, with only the caddisflies Beraeoptera roria (Trichoptera: Conoesucidae) and Confluens sp. (Trichoptera: Conoesucidae) showing significant increases in abundance. The abundance of juvenile Deleatidium sp. had a negative concentration-response relationship that resulted in an 82% decrease in abundance in the HIGH treatment. Drift of invertebrates showed no response to ammonia treatments. The 29-day EC50 values for Deleatidium sp. for total and unionized ammonia were 2.15 mg (N)/L (pH 8.4) and 0.145 mg (NH3-N)/L. No observed effect concentration (NOEC) values were 0.95 mg (N)/L and 0.066 mg (NH3-N)/L, and the threshold effect concentration (TEC) was 1.49 mg (N)/L and 0.102 mg (NH3-N)/L. Comparison of the Deleatidium sp. chronic ammonia sensitivity data with the US EPA 1985 chronic criterion value (CCC = 0.45 mg [N]/L, pH 8.4, 16°C) showed the TEC value for total ammonia was 3.3× CCC, and 2.2× higher than the updated US EPA 1998 criteria. The findings suggest that use of the US EPA criteria would provide minimal protection for Deleatidium for chronic ammonia exposure, and that development of site-specific criteria, covering a wide range of environmental conditions, may be required to adequately protect this species.
Uptake of Particulate Lead via the Gills of Fish (Carassius auratus) by S. Tao; C. Liu; R. Dawson; J. Cao; B. Li (pp. 352-357).
Carassius auratus were exposed to mixtures of constant free lead (0.1 mg/L) and particulate lead (adsorbed on gibbsite particles) at varied concentrations (0, 0.4, 0.8, 1.2, 2.0, and 3.0 mg/L). The concentrations of lead and aluminum in the gills and intestines of the fish were determined after exposure. The gills were examined (after the exposure) with a light microscope for any particles adhering to the surface. The examination results revealed that lead accumulations on the gills increased with increased particulate lead concentrations in the ambient water (under conditions of a constant level of free lead), indicating the bioavailability of lead via the gills. Gibbsite particles were also observed on the gill surface after exposure. The ratio of lead and aluminum in the gills was much higher than that in the particles. Our results suggest that there was a two-step process involved in the uptake of particulate lead by fish gills: (1) adherence of the particles on the gill surface where mucus was attached; and (2) desorption of lead from the particles under conditions of the gill microenvironment.
Cytological and Biochemical Alterations in Carassius auratus Hepatocytes from Exposure to Sediment Containing Dioxins and Related Compounds by W. Z. Wu; B. S. Zhou; Y. Xu; K.-W. Schramm; A. Kettrup (pp. 358-363).
Cytological and biochemical alterations of crucial carp (Carassius auratus) hepatocytes were characterized after exposure to sediments from a lake contaminated with dioxins and other industrial chemicals. Carp were exposed in 20 L water containing 25, 50, or 100 g of contaminated sediment for 2 and 4 weeks. Ultrastructural changes in the liver were characterized by severe enlargement of hepatocytes. Alterations in the cell included formation of condensed and irregular cell nucleus, polynuclei, dispersed heterochromatin, enlargement of the nucleolus, and degeneration of the nucleus. Mitochondrial numbers were reduced and cristae were deformed. Myelin figures and lysosomes were increased, and sometimes cell organelles and cell matrix were totally lost after 4 weeks of exposure. The ultrastructural alterations were correlated with exposure time and sediment concentrations. Hepatosometic index was significantly increased in experimental groups at 2 and 4 weeks as compared with the control group. EROD enzyme activities were strongly induced in liver. A trend from rough endoplasmic reticulum (RER) to SER was observed. Our results suggest that the dioxin-like compounds bound by sediment were bioavailable to C. auratus and cause sublethal effects.
Relative Distribution of Polychlorinated Biphenyls Among Tissues of Neonatal American Alligators (Alligator mississippiensis) by T. A. Bargar; C. Sills-McMurry; R. L. Dickerson; W. E. Rhodes; G. P. Cobb (pp. 364-368).
Recent papers have investigated the utility of chemical analysis of the chorioallantoic membrane (CAM) as a nonlethal indicator of avian and reptilian exposure to persistent environmental contaminants. This study was undertaken to evaluate the chemical distribution among fat, CAM, and residual yolk tissues of live neonatal American alligators (Alligator mississippiensis) to investigate the potential utility of CAM use as a nonlethal indicator of exposure to polychlorinated biphenyls (PCBs). CAMs were collected from neonatal alligators at hatch, whereas yolk sacs and fat tissues were taken from each animal at euthanization (3 weeks posthatch). All collected tissue samples were separately Soxhlet extracted and analyzed by GC/ECD for PCBs. Log normalized, individual PCB congener concentrations in CAMs were significantly correlated with concentrations in fat (r2 = 0.62) and yolk (r2 = 0.56) tissues. Coefficients of determination from comparisons of homologue group concentrations varied from 0.13 to 0.90. Residue levels in neonatal oviparous organism tissues may be qualitatively assessed through chemical analyses of CAM tissues removed from discarded eggshells.
Effects of Mercury on Health and First-Year Survival of Free-Ranging Great Egrets (Ardea albus) from Southern Florida by M. S. Sepúlveda; G. E. Williams, Jr.; P. C. Frederick; M. G. Spalding (pp. 369-376).
The objectives of this study were to determine whether elevated mercury (Hg) concentrations have a negative impact on the health and survival of nestling and juvenile free-ranging great egrets (Ardea albus) from southern Florida. During 1994, when health and survival was monitored in a cohort of young birds with naturally variable concentrations of Hg, packed cell volume was positively correlated with blood Hg concentrations, and high Hg concentration in blood was not related to the probability of surviving during the first 10.5 months of life. During 1995, 70 first-hatched great egret chicks were included in a Hg field-dosing experiment to compare the effects of elevated Hg on health and survival. Birds were dosed while in the nest orally every 2.5 days for 15 days with 0.5 mg of methyl mercury chloride (MeHgCl) for an estimated intake of 1.54 mg MeHgCl/kg food intake. These birds were compared with controls, which received an estimated 0.41 mg MeHgCl/kg food. No differences were observed in health parameters or in the probability of surviving during the first 8 months of age between egrets that were dosed with Hg and those that were not. A likely explanation for the lack of any effects on health and survival between both groups could be that chicks at this age were eliminating most of the dietary Hg through the production of new feathers.
Cadmium and Lead Exposure Associated with Reduced Growth Rates, Poorer Fledging Success of Little Blue Heron Chicks (Egretta caerulea) in South Louisiana Wetlands by S. A. Spahn; T. W. Sherry (pp. 377-384).
Persistent contaminants in ecosystems are often monitored via organisms that bioaccumulate the pollutant of interest. Several published studies have used colonial wading birds to assess contamination by heavy metals in aquatic ecosystems. Using a nonlethal sampling regimen, this study identified chick feathers and guano as tissues that best reflect local contamination. Both cadmium and lead were detected in food samples (0.3–4.3 μg/g Cd, 0.8–9.3 μg/g Pb), guano (0.2–3.2 μg/g Cd, 1.0–9.5 μg/g Pb), and feathers (0.6–25.4 μg/g Cd, 1.2–16.9 μg/g Pb) from little blue heron chicks at levels similar to other studies. Chicks exposed to cadmium had significantly slower growth rates than nonexposed chicks, and exposure to lead was correlated with increased nestling mortality. The appropriate scale of comparison necessary to demonstrate these effects and the usefulness of wading birds as bioindicators are discussed.
Metal Concentrations in the Eggs of Endangered Florida Scrub-Jays from Central Florida by J. Burger; G. E. Woolfenden; M. Gochfeld (pp. 385-388).
We analyzed metal levels in the eggs of the endangered Florida scrub-jay (Aphelocoma coerulescens), an extremely sedentary and modestly long-lived passerine bird. Eggs were obtained as part of the long-term study of this species at the Archbold Biological Station, located in south central Florida. Following a brief and usually short dispersal, Florida scrub-jays remain in a permanent territory in their scrub oak habitat, where they feed mainly on insects and acorns. As they are low on the food chain and sedentary, we expected levels of contaminants to be comparatively low and to reflect the local environment. No significant yearly differences existed for any metal between eggs collected in 1997 (n = 11) and 1998 (n = 5). Arithmetic mean metal concentrations (whole egg, dry weight) were low for arsenic (34 ppb), cadmium (25 ppb), mercury (74 ppb), and lead (66 ppb), intermediate for chromium (226 ppb), and higher for selenium (1,470 ppb) and manganese (2,230 ppb). Except for the low mercury value, all these means were within the range of mean values reported for a wide range of nonpasserine species, including those at high trophic levels, but are lower than concentrations associated with abnormalities in birds. The three essential elements (chromium, selenium, and manganese) were approximately normally distributed, whereas arsenic, cadmium, lead, and mercury were highly skewed (arithmetic mean much higher than geometric mean).
Comparative Study of Cadmium Transfer in Ewe and Cow Milks During Rennet and Lactic Curds Preparation by S. Mehennaoui; A. Delacroix-Buchet; A. Duche; B. Enriquez; M. Kolf-Clauw; G. Milhaud (pp. 389-395).
Cadmium transfer from whole milk to cream, rennet, or lactic curds was studied before and following a repeated oral cadmium administration to three lactating ewes and one cow. Before cadmium administration, the cadmium levels in milk were around 0.4 μg/L in ewes and less than 0.2 μg/L in cow. Throughout cadmium administration the mean cadmium levels in milk were 3.3 ± 1.4 μg/L in ewes and 2.5 ± 1 μg/L in cow. During cadmium administration, 86% of cadmium in ewe milk was dispersed in the skimmed milk and 17% in the cream, whereas only 72% was dispersed in the cow skimmed milk and 27% in the cow cream. Most of milk cadmium was associated with casein fractions. About 70% of milk cadmium was transferred to the rennet or lactic curds of ewe. The remaining cadmium present in whole milk, about 9%, was transferred to the rennet or lactic curd whey. In cow, the proportion of cadmium associated with rennet or lactic curds, rennet curd whey, and lactic curd whey was, respectively, 60%, 56%, 14% and 12% of total milk cadmium. The fraction of total cadmium transferred from milk to its milk products, whatever the species, ranged from 94% to 103%. The factor of concentration of cadmium from whole milk to milk products ranged from three to six. We suggest that the excretion of cadmium into milk is mainly achieved via the milk casein secretion. This is, to our knowledge, the first in vivo study where the cadmium transfer from milk to its milk products after repeated cadmium oral administration to ewe and cow has been studied.
Contamination Levels and Specific Accumulation of Persistent Organochlorines in Caspian Seal (Phoca caspica) from the Caspian Sea, Russia by M. Watanabe; S. Tanabe; R. Tatsukawa; M. Amano; N. Miyazaki; E. A. Petrov; S. L. Khuraskin (pp. 396-407).
Persistent organochlorines, such as polychlorinated biphenyls (PCBs) including coplanar congeners, DDTs, HCHs, chlordanes (CHLs), and HCB, were determined in the blubber of Caspian seals (Phoca caspica) and their fish diet (Rutilus sp.) collected in 1993 from the northern Caspian Sea, Russia. Notable concentrations of DDTs and HCHs were found at mean values of 19 and 1.3 μg/g on wet-weight basis in adult male seals, respectively. PCB pollution in Caspian seals was not so considerable compared with those of seals that suffered mass mortality. Less gender difference of organochlorine residue levels in adult animals implies less excretion of organochlorines from the body of adult females through lactation and gestation, probably due to the higher rate of pregnancy failure. Immature seals had a wide range of organochlorine concentrations, which decreased as body length increased, suggesting dilution. Caspian seals can be considered to have higher degradation capacity for coplanar PCBs. Mean TEQs (2,3,7,8-TCDD toxic equivalents) for non-, mono- and di-ortho coplanar PCBs was 51 pg/g on wet-weight basis, which was lower than those in seals that have suffered mass mortality, but comparable to those found in Arctic seals.
Distribution of PCB Congeners, DDE, Hexachlorobenzene, and Methylsulfonyl Metabolites of PCB and DDE Among Various Fractions of Human Blood Plasma by K. Norén; C. Weistrand; F. Karpe (pp. 408-414).
The concentrations of chlorinated biphenyls (CBs), 1,1-bis(4-chlorophenyl)-2,2-dichloroethene (DDE), hexachlorobenzene (HCB), and the methylsulfonyl metabolites of CBs (MeSO2-CBs) and DDE (MeSO2-DDE) were determined in human plasma samples and in the fractions obtained by ultracentrifugation of plasma into very-low-density (VLDL), low-density (LDL), high-density (HDL) lipoprotein and lipoprotein depleted (LPDP) fractions (containing primarily albumin). The concentrations of triacylglycerols, cholesterol, phospholipids, and apolipoprotein B (apoB) were determined. The organochlorine compounds were associated with all fractions, but predominantly with the LPDP fraction. On an average 44% of CBs, 61% of MeSO2-CBs, 73% of DDE, 77% of MeSO2-DDE, and 45% of HCB were distributed in the LPDP fraction. A tendency to greater association of 3-methylsulfonyl substituted than of corresponding 4-methylsulfonyl substituted chlorobiphenyls to the LPDP fraction was noticed. Among the lipoprotein fractions, LDL was the main carrier of HCB, DDE and CBs. MeSO2-DDE was predominantly found in HDL and MeSO2-CBs were distributed equally among the LDL and HDL fractions. Calculating the concentrations of organochlorine compounds in relation to the content of apoB, the levels were about 10 times higher in VLDL than in LDL.
Human Semen Quality in Relation to Dietary Pesticide Exposure and Organic Diet by R. K. Juhler; S. B. Larsen; O. Meyer; N. D. Jensen; M. Spanò; A. Giwercman; J. P. Bonde (pp. 415-423).
The objective of the study was to corroborate or refute the hypothesis that farmers having a high intake of organic grown commodities have a high semen quality due to their expected lower level of dietary pesticides intake. Food frequency data and semen were collected from 256 farmers (171 traditional farmers and 85 organic farmers, overall participation rate: 32%) who were selected from central registers. Each farmer delivered one semen sample before the spraying season started. The farmers were divided into three groups where the commodities from organic production contributed no (N, 0%), medium (M, 1–49%), or a high (H, 50–100%) proportion of the fruit and vegetables consumed. Farmers having a high relative intake of organically grown fruit and vegetables also had a high relative consumption of organically produced meat, milk, and bread, and differences were observed comparing the actual mean intake of single commodities, such as rice, potato, and pork meat. The current individual dietary intake of 40 pesticides was estimated using food frequencies and generalized serving size data in combination with data on pesticide concentrations in food commodities as obtained from the National Danish Food Monitoring Program. The estimated pesticide intake was significantly lower among farmers of group H, but for all three groups of farmers the average dietary intake of 40 pesticides was at or below 1% of the acceptable daily intake (ADI) except for the dithiocarbamates (max = 0.21 μg/kg day = 2.2% ADI), methidathion, (max = 0.01 μg/kg day = 1.4% ADI), and 2-phenylphenol (max = 0.21 μg/kg day = 1.1% ADI). The median sperm concentration for the three groups of farmers was not significantly different (p = 0.40, median sperm concentration was N = 62, M = 44, and H = 75 million/ml). The group of men without organic food intake had a significant lower proportion of morphologically normal spermatozoa, but in relation to 14 other semen parameters no significant differences were found between the groups. Intake of 40 individual pesticides was correlated with four semen parameters (concentration, percentage dead spermatozoa, percentage normal sperm heads, and motility [VCL]). Five significant correlations (p value 0.01) were found among the 160 comparisons in relation to percentage dead spermatozoa: azinphos-methyl, carbaryl, chlorfenson, fenitrothion, and tetradifon. For all of them a lower percentage of dead spermatozoa were found in the groups with a high dietary intake of the specific pesticide. In contrast, for all pesticides evaluated only minor differences were found between the groups when considering spermatozoa concentration, morphology, and motility. In conclusion, the estimated dietary intake of 40 pesticides did not entail a risk of impaired semen quality, but precautions should be taken when generalizing this negative result to populations with a higher dietary exposure level or an intake of other groups of pesticides.