Serum concentrations of organochlorines in men: a search for markers of exposure

Analysis of single marker substances in serum could provide cost-effective assessment of human exposure to complex mixtures of organochlorines. We studied the serum concentrations of 10 polychlorinated biphenyl (PCB) congeners and 11 chlorinated pesticides and some of their metabolites in samples collected from 120 Swedish men (mean age 63 years, range 40-74 years) from the general Swedish population. The median concentrations of individual PCB congeners increased in the order PCB 52 < PCB 101 < or = PCB28 < PCB 105 < PCB 167 < PCB 156 < PCB 118 < PCB 138 < PCB 180 < PCB 153. The concentrations of o,p'-DDT, o,p'-DDE, p,p'-DDD, alpha-HCH and gamma-HCH were in most cases below the quantification limit (2-4 ng/g lipid). Among the other chlorinated pesticides the median concentration increased in the order oxychlordane (12 ng/g lipid) < p,p'-DDT < trans-nonachlor < beta-HCH < HCB < p,p'-DDE (586 ng/g lipid). The observed concentrations of PCB and chlorinated pesticides were in the same range as those found in similar groups of men from Sweden and Norway, but lower than those found in male populations with recent occupational exposure or high environmental exposure. Strong relationships were found between the concentrations of single mono- and di-ortho PCB congeners and groups of PCB congeners in serum. In our group of men PCB 153 was a good marker substance for the concentration of sigma PCB and sigma di-ortho PCB concentrations in serum. Moreover, among the mono-ortho PCB congeners analyzed, PCB 156 could be used as a marker for the sigma mono-ortho PCB TEQ concentrations in serum in the studied group. No useful marker substances were found among DDT compounds and other chlorinated pesticides and metabolites, except for trans-nonachlor which predicted the concentration of the metabolite oxychlordane fairly well.     

Identification of subwatershed sources for chlorinated pesticides and polychlorinated biphenyls in the Ballona Creek watershed

Santa Monica Bay forms part of the western border of the greater Los Angeles region. The Ballona Creek watershed is highly urbanized and past studies indicate that Ballona Creek is the largest source for most pollutants to Santa Monica Bay. This study evaluates the contribution of subwatersheds to PCB and chlorinated pesticide loading during wet weather flow. Fifteen storm drains from these subwatersheds were sampled during three storms during the 2005-2006 winter rainy season. A series of grab samples were taken over the duration of the storms. The suspended solids were analyzed for polychlorinated biphenyls (PCBs) and chlorinated pesticides. A geographic information system (GIS) was used to calculate the runoff volume from each subwatershed to estimate pollution mass loading. There was no statistical difference among subswatersheds; however, a disproportionate mass of PCB loading came from site 5, which had no obvious sources. No specific subwatersheds were identified as key sources for chlorinated pesticides. These results may serve as a model for other locations with concerns for historic PCB and chlorinated pesticides loadings.     

Chlorinated organic pesticides in marketed food: Barcelona, 2001-06

This paper reports concentration levels of 22 chlorinated organic compounds (both primary compounds and metabolites) in food marketed in the city of Barcelona (Catalonia, Spain) in 2001-06. Samples included meat products, fish and seafood, eggs, milk and dairy, vegetal oils, cereal products and derivates, vegetables, fresh fruits, dry fruits, spices, formula and baby food, tea and wine. Levels of chlorinated organic compounds were determined by gas chromatography with selective detectors: electron capture (ECD), flame photometric (FPD) and confirmation with mass-spectrometry. Chlorinated organic pesticides were detected in 7 of the 1,484 samples analyzed in the 2001-06 period (0.5%): 1 dairy product, 1 fruit, 1 olive oil and 4 vegetables. Specific pesticides detected are lindane and endosulfan alpha, beta or sulphate. A decrease in both the proportion of samples with detectable residues and in the variety of chlorinated pesticides found is visible when comparing these results with those of the previous 1989-2000 period. These results suggest the gradual disappearance of regulated chlorinated organic pesticides as a consequence of the growing worldwide implementation of current regulatory agreements.     

Chlorinated pesticides and polychlorinated biphenyls in marine tucuxi dolphins (Sotalia fluviatilis) from the Cananéia estuary,southeastern Brazil

The Cananéia estuary is an important biological area on the southeast coast of Brazil. In the past, it was impacted by both chlorinated pesticides and polychlorinated biphenyls (PCBs) due to its natural location. The marine tucuxi dolphin (Sotalia fluviatilis) is a top predator in this ecosystem and can be found year round in Cananéia estuarine waters that represent an important nursing area for the species. This work investigated chlorinated compounds in the blubber of nine individuals from the Cananéia estuary. Residue levels of DDTs (0.541-125 microg g(-1) lipid wt.) were the highest, followed by PCBs (0.2-9.22 microg g(-1) lipid wt.), mirex (0.014-0.312 microg g(-1) lipid wt.), chlordanes (0.001-0.047 microg g(-1) lipid wt.), HCHs (<0.003-0.044 microg g(-1) lipid wt.), and HCB (n.d.-0.024 microg g(-1) lipid wt.). The mean p,p'-DDE/Sigma DDT ratio was approximately 0.8 and is indicative of the former DDT application in the study area. PCB contamination is suggested to be associated with atmospheric transport and relative proximity to the Cubat?o industrial complex-the most important along the Brazilian coast. Low levels of HCHs and HCB can be attributed to their high volatility in tropical environments. Concentrations of organochlorines in the blubber of marine tucuxis from the Cananéia estuary were lower than levels found in small cetacean species from developed countries, where the input of these compounds was considerably greater than in Brazil. At extremes, male dolphins can present DDT burden several orders of magnitude higher than females. Despite the high levels of total DDT found in males, the major detected compound was p,p'-DDE which is considered to be of low toxicity.     

Halogenated environmental contaminants in perch (Perca fluviatilis) from Latvian coastal areas

The environmental contamination situation in coastal areas of the former Soviet Union has up to now been more or less unknown. This study on perch (Perca fluviatilis), collected at three locations along the coast of Latvia during 1994 and 1995, provides concentrations of several ubiquitous environmental contaminants (PCBs, HCB, HCHs, 4,4'-DDT, 4,4'-DDE, 4,4'-DDD, trans-Nonachlor, 2,2',4,4'-tetrabromodiphenyl ether). The concentrations of total PCB were similar at all study locations [0.7-1.4 ppm on a lipid weight (l.w.) basis], although a site close to the City of Riga indicated the presence of a local PCB contamination source. The contamination source was identified mainly by a higher relative content of lower chlorinated PCB congeners in the samples. Local pollution sources were also indicated for HCH and DDT. A large variation in the HCH isomer composition between 1994 and 1995 at one location demonstrates short half-lives of HCHs in the environment. The brominated flame retardant compound 2,2',4,4'-tetrabromdiphenyl ether was present in the range of 6.4-10 ng/g l.w. in the perch. The clean-up method applied in this study allowed for quantification of two semi-polar contaminants frequently overlooked in Baltic biota, namely Dieldrin and bis(4-chlorophenyl) sulfone (BCPS). Concentrations of BCPS were remarkably high, i.e. in the same magnitude as the most abundant PCB congeners. The results presented shows that the contamination of, e.g. PCB in an area of the former Soviet Union, the Gulf of Riga, is similar to that observed in other parts of the Baltic area.     

Accumulation of organochlorinated pesticides by triolein-containing semipermeable membrane device (triolein-SPMD) and rainbow trout

An important advance in aquatic ecotoxicology is the development and application of biomimetic sampling technology for hydrophobic contaminants. In this paper, accumulation kinetics of five organochlorinated pesticides, i.e. hexachlorobenzene, lindan, aldrin, heptachlor epoxide and 4,4'-DDT, by triolein-containing semipermeable membrane device (triolein-SPMD) and by fish (rainbow trout) were compared in a laboratory continuous flow system. Accumulation kinetics of organochlorinated pesticides by the triolein-SPMD and by rainbow trout were linear during the exposure period of 20 d, except for lindan. Approach of an asymptote could be observed for lindan at the end of the exposure for rainbow trout. When the kinetic data were used to calculate the first-order uptake rate constants, it was found that the uptake rates of the chemicals in triolein-SPMD were 1-2.5 times higher than those in the fish. The estimated bioconcentration factors of the five pesticides in rainbow trout were in the range of 1000-7000 and the device concentration factor in the range of 1500-18000. Although equilibrium was not reached for most pesticides under 21-d exposure period, correlations between C(L)/C(w) and K(ow) (R(2)=0.887) and C(f)/C(w) and K(ow) (R(2)=0.931) could be observed which was a clear indication that triolein-SPMD accumulates chlorinated pesticides in a quite similar way as fish do. Our results show that triolein-SPMD could serve as a good surrogate for rainbow trout for simulating accumulations of chlorinated pesticides and may be used as a universal surrogate for fish in natural waters.     

PCB and organochlorine pesticides in home-produced eggs in Belgium

The level of polychlorinated biphenyls (PCB) and persistent organochlorinated pesticides (OC) in home-produced eggs was investigated in Belgium. The concentration of dichlorodiphenytrichloroethane (DDT) is above the norm for 17% of the eggs collected during the spring on 58 different locations. For PCB, aldrin, dieldrin, and chlordane, 3-5% of the samples are above the norm too. These levels are surprisingly high for compounds banned for about 30 years. Higher concentrations in home-produced eggs are expected compared to battery eggs because of contact with the environment and especially the soil. For ten selected locations, the concentration in soils, excreta and feed was measured, but no simple correlation between egg and feed or soil level could be established. Hexachlorohexane, endosulfan, endrin, methoxychlor and nitrofen were not detected in any sample.     

The relative influence of distant and local (DEW-line) PCB sources in the Canadian Arctic

Soil PCB contamination has been delineated at 18 of 21 Distant Early Warning Line (DEW-line) stations being cleaned up by the Canadian Department of National Defence (DND). As a result, detailed surface soil delineation data has been reported for contamination exceeding 1 microg/g (dw total Aroclor), which is the remedial criteria for PCB contaminated soil under the DEW-line cleanup project. The results of this delineation work has allowed us to estimate the mass of PCB contained in surface soil at these sites and to quantify the DEW-line as a source of PCBs to both local and Arctic wide contamination. Our analysis of DEW-line cleanup delineation reports suggests that pre-cleanup surface soils (top 10 cm) with over 1 microg/g PCB constituted a source of PCBs that ranged from 0.8 to 43 kg with a mean of 18 kg. The total mass of PCB at all 18 sites was 119 kg. Previous studies have described a "halo-effect" that surrounds DEW-line sites, whereby PCB signatures in soil and plants up to 10 km from source areas were attributed to the local source. At Cambridge Bay (CAM-M), Nunavut, our inventory of PCB sources and redistribution suggests that up to 3.4 kg of PCB were exported from the site to the surrounding tundra prior to cleanup. The primary mechanism of transportation appears to be wind borne particulate. Potential vapour phase emissions of PCB from contaminated soil at DEW-line sites appears to have been negligible.     

Organochlorines (PCBs and pesticides) in the bivalves Anadara (Senilis) senilis, Crassostrea tulipa and Perna perna from the lagoons of Ghana

The bivalves, Anadara (Senilia) senilis (n=95), Crassostrea tulipa (n=75) and Perna perna (n=30) from Ghana, were analyzed for their organochlorines (pesticides and PCBs) concentrations and the body burden. A comparison was done based on two different standard PCB mixtures (Aroclor 1254 and 1260) with the percentage individual congener contribution and that of the sample. From these comparisons, it appeared that the pattern of PCB residues in the samples was neither Aroclor 1254 nor 1260. On the other hand, there was seasonal qualitative difference in the pattern that is purely marine (in the dry season) versus terrestrial input (in the wet season). SigmaPCB was 0.10 microg/g dw or 2.2 microg/g lw (median values). There was no correlation between PCB concentration and lipid content reflecting the importance of indirect contamination of the bivalves. The pesticides, aldrin, dieldrin, endrin, lindane, DDTs, HCH, HCB, endosulfan, heptachlor epoxide and heptachlor, were detected. The most abundant pesticides were the SigmaDDT: 73 and SigmaHCH: 29 ng/g dw. DDT/DDE and hept./heptachlor epoxide ratios reflect their recent applications, while the ratio for aldrin/dieldrin suggests that the use of aldrin has been discontinued, at least on the coast of Ghana.     

PCDD/Fs and dioxin-like PCBs in home-produced eggs from Belgium: Levels, contamination sources and health risks

This paper discusses the dioxin TEQ levels as determined by the chemically activated luciferase gene expression assay (CALUX) and by HRGC-HRMS in eggs, soils, faeces and kitchen waste samples obtained in the CONTEGG study. The samples were collected in each Belgian province at private homes and in small gardens where chickens are held. The CALUX levels for eggs sampled in autumn were higher than the levels in eggs obtained at the same locations in spring (median values of 5.86 and 4.08 pg CALUX TEQ/g fat, respectively). The total WHO-TEQ levels in eggs, determined by HRGC-HRMS, ranged from 3.29 to 95.35 pg TEQ/g fat in autumn and from 1.50 to 64.79 pg TEQ/g fat in spring. In the soils on which the chickens forage, levels of 2.51-11.35 pg I-TEQ/g in autumn and 2.00-7.86 pg I-TEQ/g in spring were found. The congener pattern of PCDD/Fs in the eggs, soils and faeces was dominated by OCDD, in addition to 1,2,3,4,6,7,8-HeptaCDD, OCDF and 1,2,3,4,6,7,8-HeptaCDF. The predominant dioxin-like PCBs were PCB118, PCB 105 and PCB 156. The dioxin-like PCBs contributed on average 47%, 14% and 20% to the total WHO-TEQ in eggs, soils and faeces, respectively. Kitchen waste samples were very low-contaminated with dioxin-like compounds. The present results showed a good agreement between egg and soil TEQ levels for PCDD/Fs but not for dioxin-like PCBs. This study showed that current soil levels found in some private gardens do not lead to egg levels below the current EU maximal level of 6 pg total TEQ/g fat for dioxins and dioxin-like PCBs. The consumers of the analysed eggs attained 5-79% of the tolerable weekly intake (TWI) of 14 pg TEQ/kg bw for dioxins and dioxin-like PCBs by exposure to their home-produced eggs only.     

Fish tissue quality in near-coastal areas of the Gulf of Mexico receiving point source discharges

The objective of this study was to determine inorganic and organic contaminant concentrations in edible tissue of fish collected from eight coastal areas receiving wastewater discharges and from two reference locations. Trace metal residues were statistically similar regardless of the collection site. Zinc (100% detection in all samples), total mercury (100%), total arsenic (92%), copper (92%), and selenium (88%) were the more commonly detected trace metals. Mercury concentrations exceeded the Florida health-based standard of 0.5 microg/g for limited fish consumption in 30% of the total samples and averaged 0.40 (+/- 1 S.D. = 0.22, range < or = 0.08 to 0.85) microg/g wet weight. The average total PAH concentrations were 1.79 (+/- 1.60) ng/g (reference areas) and 2.17 (+/- 3.29) ng/g (wastewater-impacted areas). Pyrene was detected most frequently (63% of the total samples) and averaged 0.74 (+/- 0.35) ng/g wet wt. The average total PCB concentrations were 4.8 (+/- 7.1) ng/g (reference areas) and 31.6 (+/- 31.3) ng/g (wastewater-impacted areas) Concentrations of dieldrin and cis-chlordane were approximately eight times greater, respectively, in fish collected from wastewater receiving waters, whereas total DDT and total pesticide concentrations were not elevated in the same areas. Concentrations of total PCBs and all chlorinated pesticides were below US health-based standards. The lack of a published reference data base for fish tissue quality in near-coastal areas of the Gulf of Mexico restricts an assessment of the environmental significance of results from this and similar studies investigating the fate of point source contaminants.     

The use of blue tit eggs as a biomonitoring tool for organohalogenated pollutants in the European environment

In the present study, large scale geographical variation in the occurrence of organohalogenated pollutants (OHPs) was investigated throughout Europe using eggs of a terrestrial resident passerine species, the blue tit (Cyanistes caeruleus). Blue tit eggs from 10 sampling locations, involving suburban, rural and remote areas, in 7 European countries were collected and analysed. Sum polychlorinated biphenyl (PCB) levels ranged from 150 ng/g lipid weight (lw) to 2003 ng/g lw. Sum polybrominated diphenyl ethers (PBDEs) ranged from 3.95 ng/g lw to 114 ng/g lw. As expected, PCB and PBDE concentrations were significantly higher in the sampled suburban locations compared to the rural and remote locations. Sum organochlorine pesticides (OCPs) ranged from 122 ng/g lw to 775 ng/g lw. OCP concentrations were, against the expectations, found to be lower in the rural sampling locations compared to the other locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local contamination sources. Finally, we compared the results of this study with previously reported OHP concentrations in the eggs of a closely related species, the great tit (Parus major), from the same sampling locations in Europe. We found no differences in concentrations between the species. In addition, we found a significant, positive correlation between the sum PCB concentrations in blue tit eggs and great tit eggs, suggesting similar exposure pathways, mechanisms of accumulation and maternal transfer of PCBs. In conclusion, our results suggest the usefulness of eggs from passerine birds as a biomonitoring tool for OHPs on a large geographical scale.     

Loggerhead sea turtle (Caretta caretta) egg yolk concentrations of persistent organic pollutants and lipid increase during the last stage of embryonic development

Data are scarce describing the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides in sea turtle eggs. The purpose of this study was to establish appropriate sample collection methodology to monitor these contaminants in sea turtle eggs. Contaminant concentrations were measured in yolk samples from eggs that failed to hatch from three loggerhead sea turtle (Caretta caretta) nests collected in southern Florida to determine if concentrations change through embryonic development. One to three egg yolk samples per nest were analyzed from early, middle, and late developmental stages (n=22 eggs total). PCB and pesticide concentrations were determined by gas chromatography with electron capture detection (GC-ECD). Geometric mean concentrations of summation operatorPCBs (52 congeners), summation operatorDDTs, summation operatorchlordanes, and dieldrin in all eggs were 65.0 (range=7.11 to 3930 ng/g lipid), 67.1 (range=7.88 to 1340 ng/g lipid), 37.0 (range=4.04 to 685 ng/g lipid), and 11.1 ng/g lipid (range=1.69 to 44.0 ng/g lipid), respectively. Early and middle developmental stage samples had similar concentrations of PCBs and organochlorine pesticides on a wet-mass basis (ng/g tissue extracted), but the concentrations doubled by the late stage. This increase is most likely attributable to the 50% increase in lipid content observed in the late-stage yolk. These findings indicate that an early-stage sample cannot be directly compared to a late-stage sample, especially from different nests. These preliminary findings also allowed us to calculate the minimum number of eggs per nest required for analysis to obtain an acceptable mean concentration per nest. More research is required to investigate geographical trends of contaminant concentrations and potential health effects (i.e., abnormalities) caused by these contaminants on sea turtle development.     

The status of soil contamination by semivolatile organic chemicals (SVOCs) in China: a review

This paper summarizes the published scientific data on the soil contamination by semivolatile organic chemicals (SVOCs) in China. Data has been found for more than 150 organic compounds which were grouped into six classes, namely, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and phthalic acid esters (PAEs). An overview of data collected from the literature is presented in this paper. The Chinese regulation and/or other maximum acceptable values for SVOCs were used for the characterization of soils. In general, the compounds that are mostly studied in Chinese soils are OCPs, PAHs and PCBs. According to the studies reviewed here, the most abundant compounds were PAEs and PAHs (up to 46 and 28 mg kg(-1) dry weight, respectively); PCBs and OCPs occurred generally at concentrations lower than 100 microg kg(-1) dry weight. Nevertheless, quite high concentrations of PCDD/Fs, PCBs and PBDEs were observed in contaminated sites (e.g., the sites affected by electronic waste activities). The average concentrations of PAHs and OCPs in soils of North China were higher than those in South China. The principal component analysis demonstrated different distribution patterns for PAH, PCB and PCDD/F congeners and for the various sites/regions examined. The isomer ratios of DDTs and hexachlorocyclohexanes (HCHs) indicated different sources and residue levels in soils. Finally, this review has highlighted several areas where further research is considered necessary.     

Organochlorine levels in maternal and umbilical cord blood plasma in Arctic Canada

A baseline for exposure to organochlorine and metal contaminants has been established for mothers and newborns in the Northwest Territories and Nunavut areas of Arctic Canada. Maternal and umbilical cord blood plasma organochlorine levels are described for Inuit, Dene, Métis, Caucasian and Other non-Aboriginal participants. Overall, 523 women volunteered to participate by giving their written informed consent between May 1994 and June 1999, resulting in the collection of 386 maternal blood samples, 407 cord blood samples and 351 maternal/cord pairs. Nearly half of all the participants regularly smoked cigarettes, including 77% of the Inuit participants. Maternal and cord results are presented for PCBs (as Aroclor 1260 and 14 congeners) and organochlorine pesticides, including p,p'-DDT, p,p'-DDE, beta-hexachlorocyclohexane (beta-HCH), hexachlorobenzene (HCB), cis and trans nonachlor, heptachlor epoxide, oxychlordane, mirex, dieldrin and toxaphene. Maternal PCB levels (as Aroclor 1260) averaged 4.42 (+/-9.03) microg/l in Inuit, which was 3.3 times higher than those found in Dene/Métis, and 3.4 times higher than levels in Caucasians. Mean DDE levels were 2.8 times higher in the Other non-Aboriginal group (Chinese, Filipino, East Indian and multiple ethnicity) than in the Inuit group, at 3.99 microg/l and 1.42 microg/l, respectively. Cord blood PCB levels (as Aroclor 1260) averaged 1.16 (+/-2.42) microg/l for Inuit participants, which was 3.3-4 fold higher than the other ethnic groups. PCBs, p,p'-DDE and hexachlorobenzene were detected in all maternal samples, and p,p'-DDE was detected in all cord samples. Regression coefficients for maternal/cord pairs are presented for selected organochlorines. Other results from this study, including maternal and cord metals data, will be presented elsewhere.     

Organohalogenated contaminants in eggs of rockhopper penguins (Eudyptes chrysocome) and imperial shags (Phalacrocorax atriceps) from the Falkland Islands

In this study, we evaluated the use of seabird eggs of two common bird species from the Falkland Islands as bioindicators of contamination with organohalogenated contaminants (OHCs). We compared contamination levels and profiles of different OHCs between eggs of the rockhopper penguin (Eudyptes chrysocome) and the imperial shag (Phalacrocorax atriceps). In addition, laying order effects on OHC concentrations and profiles were also investigated in both species. For polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) as well as polybrominated diphenyl ethers (PBDEs), concentrations were significantly lower in eggs of rockhopper penguins (27.6 ± 0.70 ng/g lw, 56.5 ± 1.33 ng/g lw and 0.98 ± 0.04 ng/g lw, respectively) compared to the imperial shags (140 ± 5.54 ng/g lw, 316 ± 11.53 ng/g lw, 1.92 ± 0.15 ng/g lw, respectively). On the other hand, 2′MeO-BDE 68 and 6MeO-BDE 47, two brominated compounds of reported natural origin, were significantly higher in the penguin eggs (0.55 ± 0.05 ng/g lw and 7.01 ± 0.64 ng/g lw, respectively) compared to the shag eggs (0.17 ± 0.03 ng/g lw and 0.50 ± 0.06 ng/g lw, respectively). In addition, PCB, OCP and PBDE contamination profiles differed markedly between the two species. Various factors, such as diet, feeding behaviour, migratory behaviour and species-specific metabolism, may be responsible for the observed results. For both rockhopper penguins and imperial shags, PCB, OCP and PBDE concentrations and profiles did not significantly change in relation to the laying order. This suggests that, for both species, any egg of a clutch is useful as a biomonitoring tool for OHCs. Although our results showed that OHCs have also reached the Falkland Islands, concentrations were relatively low compared to other studies. However, future monitoring may be warranted to assess temporal trends of different OHCs.     

Biological monitoring of environmental contaminants: Chlorinated hydrocarbons in eggs of hens

High concentrations of persistent chlorinated hydrocarbon pesticide residues were detected by gas-liquid chromatography with an electron capture detector (³H), in eggs of hens collected from Lucknow under the pesticide monitoring programme. The present study reveals extremely high contamination of eggs, particularly with DDT and HCH residues. The eggs may be an important source of DDT and HCH build-up in the human body. Residue levels of p,p′-DDT and its metabolites p,p′-DDE and α, β and γ-isomers of HCH were higher in eggs of poultry-farm hens compared to those of domestic hens. Egg yolk contained higher levels compared with egg white, because of the lipophilic nature of pesticides and the high lipid content in the yolk. Average levels of total DDT and HCH residues in the yolk and white in the whole egg of a poultry-farm hen were found to be 18.5 and 4.6 μg respectively, whereas the average levels were 7.4 and 4.1 μg, respectively, in the whole egg of a domestic hen.     

PCBs in the atmosphere of King George Island,Antarctica

Polychlorinated biphenyls (PCBs) are ubiquitous anthropogenic compounds found even in the polar regions, mainly due to long-range atmospheric transport. In order to assess the occurrence of atmospheric PCBs in the vicinity of the Brazilian Antarctic Research Station (62 degrees 05'S, 58 degrees 23'W), a sampling survey was undertaken in the austral summer of 1995-1996. The concentrations of the PCB congeners in the air ranged from not detected to 33.2 pgm(-3). The lower chlorinated congeners (PCB-101 and below), which are more volatile and subject to long-range transport, predominated in the air samples and represented 66.7% of the total PCB concentrations. Atmospheric levels of PCBs were correlated with meteorological conditions and the highest levels were associated with the passage of the frontal systems coming from South America.     

Sexual difference in PCB concentrations of coho salmon (Oncorhynchus kisutch)

We determined polychlorinated biphenyl (PCB) concentrations in 35 female coho salmon (Oncorhynchus kisutch) and 60 male coho salmon caught in Lake Michigan (Michigan and Wisconsin, United States) during the fall of 1994 and 1995. In addition, we determined PCB concentrations in the skin-on fillets of 26 female and 19 male Lake Michigan coho salmon caught during the fall of 2004 and 2006. All coho salmon were age-2 fish. These fish were caught prior to spawning, and therefore release of eggs could not account for sexual differences in PCB concentrations because female coho salmon spawn only once during their lifetime. To investigate whether gross growth efficiency (GGE) differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, males were 19% higher in PCB concentration than females, based on the 1994-1995 dataset. Similarly, males averaged a 20% higher PCB concentration in their skin-on fillets compared with females. According to the bioenergetics modeling results, GGE of adult females was less than 1% higher than adult male GGE. Thus, bioenergetics modeling could not explain the 20% higher PCB concentration exhibited by the males. Nonetheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations.     

Chlorinated hydrocarbon contaminants in feces of river otters from the southern Pacific coast of Canada, 1998-2004

Chlorinated hydrocarbon contaminants in coastal river otters (Lontra canadensis) were evaluated by sampling feces (scats) collected on the south coast of British Columbia, Canada. A broad survey of industrialized areas of the Strait of Georgia region was conducted in 1998, and a subsequent survey of working harbours in 2004. Samples from 1998 were analyzed for polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides, and polychlorinated dioxins (PCDDs) and furans (PCDFs), while in 2004, chemistry was confined to summation operatorPCBs and OC pesticides. Concentrations of OC pesticides were low in both years, with only dichlorodiphenyldichloroethylene (DDE; range: 0.01-2.12 mg/kg lw) and hexachlorocyclobenzene (HCB; range: 0.003-0.25 mg/kg lw) detected in all samples. In 1998, octachlorodibenzo-p-dioxin (OCDD) and other higher chlorinated PCDD/Fs were found in most samples, with OCDD ranging from 120 ng/kg lw in Clayoquot Sound to 19,100 ng/kg lw in a pooled sample from two latrines in Nanaimo. PCBs were present in all samples. In 1998 geometric mean concentrations of the sum of 59 PCB congeners ranged from 0.49 mg/kg lw in Nanaimo to 12.3 mg/kg lw in Victoria Harbour. Six years later, mean summation operatorPCBs remained elevated (geometric mean 9.5 mg/kg lw) in Victoria Harbour. Geometric mean concentrations of summation operatorPCBs from Victoria Harbour in 1998 and 2004 were >9 mg/kg lw, a published adverse effect level for reproduction. At some latrines in both Victoria and Esquimalt Harbours, concentrations of TCDD-toxic equivalents exceeded 1500 ng/kg lw, a value for health effects in otters that we derived using published information. As shown in previous studies, analysis of scats provides an efficient and non-intrusive approach to assessing contaminant threats to otter populations, and to documenting spatial trends in residues.