Organohalogen Contaminants Research Articles

Estimation of Daily Intake of Organohalogenated Contaminants from Food Consumption and Indoor Dust Ingestion in Romania

We estimated human exposure to organohalogenated contaminants (OHCs), including organochlorine pesticides (OCPs), such as hexachlorocyclohexanes (HCHs), DDT and metabolites, hexachlorobenzene, and chlordanes, but also polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecane (HBCD), through food consumption (mainly food of animal origin) and indoor dust ingestion in Romania. A total of 71 food samples (meat, diary products, vegetable cooking oil, and eggs from urban supermarkets and rural areas) and 18 indoor dust samples were collected from Iasi, Eastern Romania. HCHs and DDTs were the most prevalent OCPs in both food and dust samples. Higher levels of OCPs were measured in food samples collected from rural areas compared to those from urban supermarkets, except milk-based products for which no significant differences could be recorded. However, levels of contamination with HCHs in milk-based products were occasionally higher than current European maximum residue levels (MRLs). Above-MRL levels of DDTs were also recorded in eggs from rural areas. In dust, DDTs (median concentration of 1050 ng/g) were the most prevalent contaminants and p,p'-DDT was consistently the main contributor of sum DDTs, with a contribution between 50 and 75%. Surprisingly, OCPs, mainly DDT, were found at elevated levels in indoor dust samples (median concentrations for sum OCPs of 1200 ng/g dust). This suggests the importance of dust as an exposure route for pesticides (especially at contaminated sites), since dust is not commonly considered in exposure assessments for these chemicals. The main contributor to the sum PBDEs in dust samples was BDE 209 (median concentration of 495 ng/g), with a contribution between 94 and 99%. We estimated that the dietary intake of SigmaHCHs and SigmaDDTs is high for both adults (1500-2100 ng/day) and toddlers (1100-1500 ng/day), while the PCB dietary intake was estimated at 200 ng/day for adults, being compared to other European studies. The contribution of dust ingestion to the daily intake of PBDEs is increased in comparison to intake of other chlorinated contaminants, while food consumption seems to be more important than dust for the HBCD intake. However, neither BDE 209 nor HBCD were measured at levels above method LOQ in any food samples and their dietary intake is probably overestimated because nondetects were replaced by (1)/(2) LOQ. The estimated intakes obtained in the present study are in good agreement with the higher concentrations of OCPs and the low levels of PBDEs reported recently in Romanian human samples.

Testosterone concentrations and male genital organ morphology in Greenland sledge dogs (Canis familiaris) dietary exposed to organohalogen contaminants

This study investigated whether low-level, long-term in utero and post-natal exposure to organohalogen pollutants disrupts male reproductive organ morphology and testosterone production in Greenland sledge dogs (Canis familiaris), as a model of Arctic top predators feeding on marine mammals. Six male dogs were followed for 1 year and testosterone concentrations, testes/baculum morphology and baculum bone mineral density (BMD) was determined. Three males were exposed to organohalogenated contaminants (OHCs) in utero through maternal dietary intake of minke whale blubber (Balaenoptera acutorostrata), with a post-weaning ∑OHC intake of 10.4–11.7 µg kg−1 day−1 resulting in an adipose tissue range of ∑OHC 4518–5729 ng (g lw)−1 after 1 year. Three control males were exposed to very low concentrations of OHCs through pork fat. No significant differences were seen in plasma testosterone concentrations, baculum weight, BMD, and testicular length in the six male dogs (control, n = 3 and exposed, n = 3) measured at 3, 5, 7, 9, and 12 months of age. Testicular weights were significantly lower in the exposed group (p = 0.015, n = 2). Although this study had a limited number of animals, it was observed that in utero and the following 12 months of chronic exposure to a complex mixture of contaminants in the form of naturally accumulated OHCs does not affects testosterone levels, but possibly affects testicular weights in sledge dogs.

Organohalogens in A Whale-Blubber-Supplemented Diet Affects Hepatic Retinol and Renal Tocopherol Concentrations in Greenland Sled Dogs (Canis familiaris)

The aim of this study was to examine the plasma, liver, and kidney status of vitamin A (retinol) and vitamin E (α-tocopherol) in two groups of Greenland sled dogs (Canis familiaris), with a total number of 16 bitches and 8 pups. The dogs were fed either minke whale (Balaenoptera acuterostrata) blubber (exposed dogs) or uncontaminated (control group) porcine fat for up to 12 to 21 mo of age. The daily intake of 50–200 g whale blubber (mean: 112 g) constituted between 10.4 and 11.7 µg/kg body weight ∑organohalogen contaminants (OHC) (or between 4.6 and 6.1 µg/kg body weight ∑polychlorinated biphenyls [PCB]). Retinol was approximately 18% and α-tocopherol 22% higher in the diet of the exposed dogs compared to controls. In adipose tissue, mean of ΣOHC was 92 ng/g lipid weight (lw) and 5005 ng/g lw for all control (n = 12) and exposed dogs (n = 10), respectively. Hepatic retinol correlated negatively with Σ-dichlorodiphenyldichloroethane (ΣDDT) and and Σ‐polybrominated diphenyl ethers (ΣPBDE) for all exposed animals. A negative correlation between kidney α‐tocopherol and ΣPCB concentrations was observed, whereas two positive significant correlations were observed between kidney retinol and Σ-chlordane-related compounds (ΣCHL) and dieldrin concentrations. Hepatic α-tocopherol concentrations were significantly lower in exposed compared to controls, most likely due to a combination by OHC exposure and high dietary intake of unsaturated fatty acids. These results suggest that dietary exposure from OHC may, even at low concentrations, possibly affect retinol and α-tocopherol status in Arctic top predators.

Organohalogen contaminants in finless porpoises (Neophocaena phocaenoides) from Korean coastal waters: Contamination status, maternal transfer and ecotoxicological implications

Information on the occurrence of organochlorine compounds (OCs) and polybrominated diphenyl ethers (PBDEs) in marine mammals from Korea is scarce. In this study, OCs and PBDEs were determined in the blubber of 52 finless porpoises (Neophocaena phocaenoides) from Korean coastal waters. The highest contamination was found for DDTs, followed by PCBs, PBDEs, HCHs, CHLs and HCB. Concentrations of OCs in finless porpoises were lower than those reported worldwide, but PBDE contamination was comparable to other studies, due to ongoing use of PBDE products in Korea. Significant gender-specific differences were found for concentrations and accumulation profiles of OCs and PBDEs, due to maternal transfer and lactation of mature females. The BDEs 49 and 66 comprised 4–16% of total PBDEs in finless porpoises, which seems to be associated with debromination of higher BDEs. The DDT levels in Korean finless porpoises have almost reached the levels associated with immunosuppression in marine mammals.

Organohalogen contaminants in blood of Kemp’s ridley ( Lepidochelys kempii) and green sea turtles ( Chelonia mydas) from the Gulf of Mexico

The threat that exposure to organohalogen (OH) contaminants poses to endangered populations of Kemp’s ridley ( Lepidochelys kempii) and green sea turtles ( Chelonia mydas) is not well understood, partly because few OH data are available. Blood samples from live juvenile and sub-adult L. kempii ( n = 46) and C. mydas ( n = 9) from the Gulf of Mexico and from L. kempii from the southeastern US coast ( n = 3) were extracted using microwave-assisted extraction, and analyzed by large volume injection gas chromatography–mass spectrometry for 85 polychlorinated biphenyls (PCBs), 25 organochlorine pesticides (OCPs) and 27 polybrominated diphenyl ethers (PBDEs). Plasma chemistries, hematology and immune responses were also assessed. Concentrations of ΣPCBs (geometric mean, range: 3190 pg g −1, 227–21 590 pg g −1 blood), ΣDDTs (geometric mean, range: 541 pg g −1, 161–4310 pg g −1 blood) and OCPs in L. kempii from the Gulf were comparable to those reported in L. kempii from the Atlantic. ΣPBDEs were detected in all samples (geometric mean, range: 146 pg g −1, 19.5–1450 pg g −1 blood), with PBDE 47, 99, 100, 153 and 154 being the predominant congeners. ΣPCBs, ΣDDTs and Σchlordanes were one order of magnitude lower in green turtles, and ΣPBDE concentrations were lower by half due to trophic level differences. L. kempii from the southeast USA had higher percentages of highly chlorinated PCBs indicating exposure to Aroclor 1268. Blood urea nitrogen was positively correlated to Σchlordanes, and ΣPCBs were inversely correlated to creatine phosphokinase in L. kempii. These data help establish baseline contaminant concentrations in live L. kempii and C. mydas.

Recombinant Albumin and Transthyretin Transport Proteins from Two Gull Species and Human: Chlorinated and Brominated Contaminant Binding and Thyroid Hormones

Environmentally relevant concentrations of selected polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) flame retardant congeners and their hydroxylated (OH) and methoxylated (MeO) analogues that can perturb thyroid hormone-dependent processes were comparatively examined with respect to competitive binding with thyroxine (T(4)) and 3,5,3'-triiodothyronine (T(3)) thyroid hormones (THs) on recombinant human and gull albumin and transthyretin transport proteins. The liver tissue was from glaucous gulls (Larus hyperboreus) from Norway and herring gulls (Larus argentatus) from the Great Lakes of North America. We isolated, cloned, sequenced, purified, and expressed the cDNA (cDNA) of albumin from liver of herring and glaucous gull. Albumin amino acid sequences were identical for both gull species. Concentration-dependent, competitive binding curves were generated for T(4) and T(3) binding alone and for selected substrates using gull and human recombinant albumin (recALB). Human recALB had high preference for T(4) relative to T(3), whereas it was reversed for gull recALB. Binding assays with recALB and recTTR gull proteins showed that relative to 2,2',4,4'-tetrabromoDE (BDE-47) and 2,2',3,4',5,5',6-heptaCB (CB-187) and the MeO-substituted (4-MeO-CB187 and 6-MeO-BDE47) analogues, 4-OH-CB187, 6-OH-BDE47, and 4'-OH-BDE49 had the greatest binding affinity and potency, and that competitive binding was greater for T(3) relative to T(4). These results indicate that xenobiotic ligand binding to human ALB or TTR cannot be used as a surrogate for gull binding interactions. The combination of TH-like brominated diphenyl ether backbone (relative to the chlorinated biphenyl backbone), and the presence of OH-group produced a more effective competitive ligand on human and gull recALB and recTTR relative to both T(3) and T(4). This suggests the possibility that OH-substituted organohalogen contaminants may be an exposure concern to the thyroid system in free-ranging gulls as well as for humans.

Dioxins and organohalogen contaminants in the Asia-Pacific region

This article reviews the outcome of comprehensive investigations conducted in our laboratory at CMES, Ehime University over the past three decades on the distribution, sources, temporal trends and toxic impacts of the persistent and bioaccumulative organohalogen contaminants in Asia-Pacific region with a particular emphasis on developing countries. Results of multi-media monitoring studies were compiled and discussed to provide in-depth understanding on various issues of dioxins and organohalogen contamination in both ambient environment and animals including humans. Prominent contaminations were found in the regions where they have been heavily used. The eastern Asian region is probably a potential source of pollution, particularly by the new contaminants such as polybrominated diphenyls ethers. These groups of contaminants, together with polychlorinated biphenyls, exhibited either decreasing or increasing trends depending on the extent of industrialization in Asian developing region, indicating the necessity for long term monitoring. The open dumping sites for municipal wastes in major cities are significant sources of many toxic chemicals, and these areas are probably one of the challenges for future research due to the long term impacts on the environmental quality and human health. The formation of dioxins and related compounds in such dumping sites and their elevated residues found in breast milk of residents living in and around warrant long term impacts of dioxins upon next generations. Comprehensive and long term monitoring programs are urgently needed with close collaboration and proper capacity building in Asian developing countries in order to mitigate dioxin and organohalogen emission and their risk on ecosystems and human health.

Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull ( Larus hyperboreus)), polar bears ( Ursus maritimus), polar (Arctic) fox ( Vulpes lagopus), and Arctic charr ( Salvelinus alpinus), as well as semi-captive studies on sled dogs ( Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause–effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of POP/OHC exposure and mediated effects are East Greenland, Svalbard and (West and South) Hudson Bay polar bears, Alaskan and Northern Norway killer whales, several species of gulls and other seabirds from the Svalbard area, Northern Norway, East Greenland, the Kara Sea and/or the Canadian central high Arctic, East Greenland ringed seal and a few populations of Arctic charr and Greenland shark.

Reproductive performance in East Greenland polar bears ( Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling

Polar bears ( Ursus maritimus) feed mainly on ringed seal ( Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990–2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p, p′-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats ( Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79–1271 ng g −1 lw) and PCBs (range: 4128–53 923 ng g −1 lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs ⩾ 1). Similar results were found for PCBs (range: 1928–17 376 ng g −1 lw) and PFOS (range: 104–2840 ng g −1 ww) in the year 2000 and for dieldrin (range: 43–640 ng g −1 lw), PCBs (range: 3491–13 243 ng g −1 lw) and PFOS (range: 1332–6160 ng g −1 ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQs < 1 and thus appear less likely to be linked to reproductive effects. Furthermore, sumRQs above 1 suggested risk for OHC additive effects. Thus, previous suggestions of possible adverse health effects in polar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife.

Relationships between organohalogen contaminants and blood plasma clinical–chemical parameters in chicks of three raptor species from Northern Norway

Organohalogen contaminants (OHCs) may affect various physiological parameters in birds including blood chemistry. We therefore examined blood plasma clinical–chemical parameters and OHCs in golden eagle, white-tailed eagle and goshawk chicks from Northern Norway. Correlation analyses on pooled data showed that alkaline phosphatase (ALKP), glucose and creatinine were significantly negatively correlated to various OHCs (all: p<0.05; r: −0.43 to −0.55; n=23), while alanine aminotransferase (ALAT), total protein, cholesterol, uric acid, total bilirubin, ratios protein:creatinine and uric acid:creatinine were significantly positively correlated to various OHCs (all: p<0.05; r: 0.43–0.96). Based on these relationships, we suggest that the OHC concentrations found in certain raptor chicks of Northern Scandinavia may impact blood plasma biochemistry in a way that indicates impacts on liver, kidney, bone, endocrinology and metabolism. In order to elaborate further on these relationships and mechanisms, we recommend that a larger study should take place in the near future.

Organohalogen contaminants and metabolites in cerebrospinal fluid and cerebellum gray matter in short-beaked common dolphins and Atlantic white-sided dolphins from the western North Atlantic

Concentrations of several congeners and classes of organohalogen contaminants (OHCs) and/or their metabolites, namely organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), hydroxylated-PCBs (OH-PCBs), methylsulfonyl-PCBs (MeSO 2-PCBs), polybrominated diphenyl ether (PBDE) flame retardants, and OH-PBDEs, were measured in cerebrospinal fluid (CSF) of short-beaked common dolphins ( n = 2), Atlantic white-sided dolphins ( n = 8), and gray seal ( n = 1) from the western North Atlantic. In three Atlantic white-sided dolphins, cerebellum gray matter (GM) was also analyzed. The levels of OCs, PCBs, MeSO 2-PCBs, PBDEs, and OH-PBDEs in cerebellum GM were higher than the concentrations in CSF. 4-OH-2,3,3′,4′,5-pentachlorobiphenyl (4-OH-CB107) was the only detectable OH-PCB congener present in CSF. The sum (Σ) OH-PCBs/Σ PCB concentration ratio in CSF was approximately two to three orders of magnitude greater than the ratio in cerebellum GM for dolphins.

Organohalogen contaminants in striped dolphins ( Stenella coeruleoalba) from Japan: Present contamination status, body distribution and temporal trends (1978–2003)

Organohalogen contaminants including PCBs, DDTs, CHLs, HCHs, HCB, PBDEs and HBCDs were determined in striped dolphins ( Stenella coeruleoalba) found stranded at Gogo-shima ( n = 6, 2003) and collected from Taiji ( n = 15, 1978–1992) in Japan. All target compounds were significantly detected in all the specimens, indicating ubiquitous contamination of oceanic cetaceans in northwest Pacific Ocean. Examination of body distribution of organohalogens in the six specimens from Gogo-shima showed no significant difference in concentrations among the analyzed tissues, except for brain, which had lower levels possibly due to the existence of blood–brain barrier. For evaluating temporal trends, archived blubber samples of adult male stripped dolphins collected in 1978, 1979, 1986 and 1992 were analyzed. Concentrations of PCBs, DDTs and HCHs did not change significantly during 1978–2003. In contrast, remarkable increasing trends of PBDEs and HBCDs were observed, suggesting growing consumption in Japan and surrounding countries in recent years.

Persistent organohalogen contaminants in plasma from groups of humans with different occupations in Bangladesh

The present study is aimed to assess persistent organic halogenated pollutants in humans living in Bangladesh. The results are compared to other similar studies in the region and globally. Human blood plasma were collected from groups of men and women with different occupations, i.e. being students, garment industry workers, employees at the Power Development Board (PDB), all groups in Dhaka, fishermen and fishermen wife’s from Dhaka and another group from Barisal district. The plasma was analysed for hexachlorobenzene (HCB), the hexachlorocyclohexane isomers, α-HCH, β-HCH, γ-HCH and δ-HCH, the DDT group of chemicals, chlordane compounds, trans-chlordane, cis-chlordane, oxychlordane, trans-nonachlor, trans-heptachlorepoxide, methoxychlor and mirex. The most abundant contaminant, in all groups studied, p, p′-DDE is dominating, with p, p′-DDT/∑DDT ratios indicating recent and ongoing DDT exposure. Among the other pesticides analysed β-HCH is the most abundant indicating the use of technical HCH products instead of Lindane (γ-HCH). While the ∑DDT is present in the low ppm range the β-HCH is detected in up to approx. 400 ppb, lipid basis. The β-HCH is most abundant in the groups of students. In contrast to the pesticides analysed very low concentrations of polychlorinated biphenyls (PCB) are present in all study groups, with e.g. CB-153 in the range of 5–30 ng g −1 fat. The concentrations of the DDT group of chemical differ significantly between fishermen and fishermen’s wives living and working in the Dhaka area versus those living and working in Barisal. Also, fishermen and their wives had significantly different concentrations of DDT compared to garment industry workers.

Comparison of five extraction methods for measuring PCBs, PBDEs, organochlorine pesticides, and lipid content in serum

An increasing number of studies use blood obtained noninvasively to monitor organohalogen contaminants; however, blood can be difficult to analyze because of its aqueous nature and high protein content. We compared five methods for extracting polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides, and lipids from serum using National Institute of Standards and Technology Standard Reference Material 1589a PCBs, Pesticides, PBDEs, and Dioxins/Furans in Human Serum. Liquid:liquid (LLE), cavity-dispersed microwave-assisted (MAE), focused microwave-assisted (FME), solid-phase (SPE), and pressurized fluid (PFE) extraction techniques were compared. FME extraction yielded the optimal recovery of internal standards (IS). All methods resulted in similar contaminant concentrations that also agreed with the certified values for SRM 1589a, except for only a few compounds measured by methods other than FME. Based on these findings, the FME method was determined to be the best overall extraction method. One procedural factor was found to affect contaminant concentrations; use of IS carrier solvents that were immiscible with serum (or when the serum was not directly physically mixed with IS) resulted in a 30% underestimation of organohalogen concentrations. This study offers valid, novel extraction alternatives beyond traditional methods (e.g., LLE) for blood contaminant measurements.

Dietary, age and trans-generational effects on the fate of organohalogen contaminants in captive sledge dogs in Greenland

Studies on the fate of organohalogen contaminants (OHCs) in wild top predator mammals in the Arctic have often been a challenge due to important knowledge deficiencies in the life history of the sampled animals. The present study investigated the influence of age, dietary and trans-generational factors on the fate of major lipophilic chlorinated and brominated OHCs in adipose tissue of a potential surrogate captive species for the polar bear ( Ursus maritimus), the sledge dog ( Canis familiaris) in West Greenland. Adult female sledge dogs (P) and their sexually-mature (F1) and/or pre-weaning pups (F1-MLK) were divided into an exposed group (EXP) fed blubber from a Greenland minke whale ( Balaenoptera acutorostrata) and a control group (CON) given commercially available pork fat. Large dietary treatment-related differences in summed and individual congener/compound adipose tissue concentrations of polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), chlordanes (CHLs) and polychlorinated biphenyls (PCBs) were found between the EXP and CON groups for all the sledge dog cohorts. However, among the F1-MLK, F1 and P dogs in both of the EXP and CON groups, little or no difference existed in PBDE, HCB, CHL and PCB concentrations, suggesting higher state of equilibrium in adipose tissue concentrations from a very early stage of life. In contrast, the distribution pattern (proportions to the summed concentrations) of OHC classes, and the major congeners/compounds constituting those classes, varied on a dietary group- and/or cohort-dependent manner. The present captive sledge dog study demonstrated the importance of the confounding effects of diet composition, mother–pup association (maternal transfer), reproductive status (nursing), and to a lesser extent age in the fate of OHCs in adipose tissue of a large top carnivore mammal.

Changes in prolactin in a highly organohalogen contaminated Arctic top predator seabird, the glaucous gull

The factors influencing prolactin (PRL) variation in birds and in wildlife in general have rarely been investigated with respect to the physiological impacts of exposure to environmental contaminants. We investigated the associations between circulating baseline PRL levels and concentrations of eight persistent organohalogen contaminant (OHC) classes (i.e., major organochlorines and brominated flame retardants, and associated metabolic products) in blood (plasma) of free-ranging glaucous gulls (Larus hyperboreus), a top predator in the Norwegian Arctic, engaged in the process of incubation. We further examined whether plasma OHC concentrations were associated with the variation of PRL in glaucous gulls exposed to a standardized capture/restraint protocol. Plasma OHC concentrations in male glaucous gulls were 2- to 3-fold higher relative to females. Baseline PRL levels tended to be higher in females compared to males, although not significantly (p=0.20). In both males and females, the 30-min capture/restraint protocol led on average to a 26% decrease in PRL levels, which resulted in a rate of PRL decrease of 0.76ng/mL/min. The baseline PRL levels and the rate of decrease in PRL levels tended to vary negatively with plasma OHC concentrations in males, but not in females, although several of these associations did not adhere with the criterion of significance (α=0.05). Present results suggest that in highly OHC-exposed male glaucous gulls, the control of PRL release may be affected by the direct or indirect modulating actions of OHCs and/or their metabolically derived products. We conclude that potentially OHC-mediated impact on PRL secretion in glaucous gulls (males) may be a contributing factor to the adverse effects observed on the reproductive behavior, development and population size of glaucous gulls breeding in the Norwegian Arctic.

Comparative fate of organohalogen contaminants in two top carnivores in Greenland: Captive sledge dogs and wild polar bears

The limited knowledge and/or the inability to control physiological condition parameters that influence the fate of organohalogen contaminants (OHCs) has been the foremost confounding aspect in monitoring programs and health risk assessments of wild top predators in the Arctic such as the polar bear ( Ursus maritimus). In the present comparative study, we used a potential surrogate Canoidea species for the East Greenland polar bear, the captive sledge dog ( Canis familiaris), to investigate some factors that may influence the bioaccumulation and biotransformation of major chlorinated and brominated OHCs in adipose tissue and blood (plasma) of control (fed commercial pork fat) and exposed (fed West Greenland minke whale ( Balaenoptera acutorostrata) blubber) adult female sledge dogs. Furthermore, we compared the patterns and concentrations of OHCs and their known or suggested hydroxylated (OH) metabolites (e.g., OH-PCBs) in sledge dogs with those in adipose tissue and blood (plasma) of East Greenland adult female polar bears, and blubber of their main prey species, the ringed seal ( Pusa hispida). The two-year feeding regime conducted with sledge dogs led to marked differences in overall adipose tissue (and plasma) OHC residue accumulation between the control and exposed groups. Characteristic prey-to-predator OHC bioaccumulation dynamics for major PCB and PBDE congeners (patterns and concentrations) and biotransformation capacity with respect to PCB metabolite formation and OH-PCB retention distinguished, to some extent, captive sledge dogs and wild polar bears. Based on the present findings, we conclude that the use of surrogate species in toxicological investigations for species in the Canoidea family should be done with great caution, although they remain essential in the context of contaminants research with sensitive arctic top carnivore species such as the polar bear.

Organohalogen pollutants in herring from the northern Baltic Sea: Concentrations, congener profiles and explanatory factors

Organohalogen contaminants were investigated in Baltic herring caught from three catchment areas in the Baltic Sea, off the coasts of Finland. Pools of both small and large herring were analysed for polychlorinated biphenyls (PCB), dibenzo- p-dioxins, dibenzofurans, naphthalenes, camphenes (toxaphene), polybrominated diphenyl ethers and the pesticide DDT and its metabolites. PCB concentrations per fresh weight in small herring were at the same level in all catchment areas, i.e. the Bothnian Bay, the Bothnian Sea and the Gulf of Finland, revealing no hot spots and reflecting most likely long term emissions and atmospheric deposition. Differences in the levels and/or congener profiles of other contaminants between catchment areas may be explained by point sources. Similar concentrations in small and large herring in the Gulf of Finland were possibly due to their common nutrition. In the other areas, differences between small and large herring most likely reflected their different food sources.

PCBs, PBDEs and pesticides released to the Arctic Ocean by the Russian Rivers Ob and Yenisei

The Ob and Yenisei Rivers contribute 37% of riverine freshwater inputs to the Arctic Basin and thus represent an important pathway for the land-Arctic ocean exchange of contaminants. Sampling was carried out in the Yenisei (2003) and Ob (2005) River estuaries and Kara Sea to address the general lack of reliable dissolved contaminant flux data for these major rivers. Contaminant analyses were performed by high resolution mass spectrometry on sample extracts taken from filtered large volume water samples (50-100 L) and concentrated in situ onto XAD-2 resin columns. Hexachlorocyclohexanes (HCHs), the polychlorinated biphenyl (PCB) mixtures Sovol and trichlorodiphenyl, dichlorodiphenyltrichloroethane (DDT), as well as "penta" brominated technical mixtures of polybrominated diphenyl ethers (PBDEs) are important contributors to persistent organohalogen contamination for these waterways. Dissolved fluxes to the Kara Sea were estimated at sigmaHCH 246 kg/yr, sigmaPCB 63 kg/yr, sigmaDDT 16 kg/yr, hexachlorobenzene 8 kg/yr, alpha-endosulfan 8 kg/ yr, dieldrin 5 kg/yr, sigmaPBDE 4 kg/yr, and chlordanes 4 kg/yr. Contaminant fluxes from these rivers are similar to those reported for major Canadian rivers, confirming expectations that the Ob and Yenisei are also major point sources for the Arctic basin.

Renal lesions in Greenland sledge dogs ( Canis familiaris ) exposed to a natural dietary cocktail of persistent organic pollutants

Persistent organic pollutants such as Polychlorinated biphenyls (PCB) and dichloro diphenyl trichloroethane (DDT) are known to exert various adverse health effects in wildlife mammals. The impact from dietary intake of minke whale (Balaenoptera acutorostrata) blubber high in organohalogen and other chemical contaminants on renal morphology and function was investigated via a controlled study on West Greenland sledge dogs (Canis familiaris). Our results showed significantly higher frequencies of glomerular, tubular, and interstitial lesions in the exposed group. Furthermore, higher urine protein : creatinine ratio and plasma urea levels were found in the exposed group, which indicated a negative impact on kidney function via tubular and glomerular dysfunctions. The lesions were similar to those observed in top predator marine species–such as seals and polar bears–and humans exposed via diet to persistent environmental pollutants. The lesions may have impacts on the overall health of these animals. It is reasonable to suggest that chronic exposure to organic pollutants via a country diet of high trophic level marine organisms may have an impact on renal morphology and function in Arctic apex predators in general as well as Inuit people.