Prenatal exposure to persistent organic pollutants in Northern Tanzania and their distribution between breast milk, maternal blood, placenta and cord blood.

Human exposure to persistent organic pollutants (POPs) begins during pregnancy and may cause adverse health effects in the fetus or later in life. The present study aimed to assess prenatal POPs exposure to Tanzanian infants and evaluate the distribution of POPs between breast milk, maternal blood, placenta and cord blood. For assessment of prenatal exposure, 48 maternal blood samples from Mount Meru Regional Referral Hospital (MMRRH), Arusha Tanzania, were analyzed for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), dioxin-like (DL) activity and perfluorinated alkyl substances (PFASs). For evaluation of POPs distribution between maternal/infant compartments, breast milk, placenta and cord blood corresponding to the maternal blood were analyzed for OCPs, PCBs and BFRs. In maternal blood, p,p´- DDE was detected in 100% of the samples ranging between 29 and 1890 ng/g lipid weight (lw). PCB-153 was the only PCB detected in maternal blood, with detection rate of 29% and concentrations up to 116 ng/g lw. BDE-47 was detected in 65% of the maternal blood samples, ranging between

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in human breast milk and associated health risks to nursing infants in Northern Tanzania.

This is the first study to report organochlorines (OCs), including chlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs) in human milk from Tanzania. The main aims of this study were to assess the level of contamination and the possible health risks related to OC exposure in nursing infants from the Northern parts of Tanzania. Ninety-five healthy mother-infant couples attending Mount Meru Regional Referral Hospital (MMRRH), Arusha, Tanzania, were assessed for associations between maternal/infant characteristics, i.e. mother's age, BMI, gestational weight gain, occupation, residence and fetal growth parameters and breast milk levels of OCPs, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, dieldrin and PCBs. p,p'-DDE and p,p'-DDT were detected in 100% and 75% of the breast milk samples, respectively, and ranged between 24 and 2400ng/g lipid weight (lw) and

Trophic level determines levels of brominated flame-retardants in coastal herring gulls.

Liver concentrations of eight polybrominated diphenyl ethers (ΣPBDEs: sum of brominated diphenyl ethers [BDE]-28, -47, -99, -100, -153, -154, -183, and -209) ranged from 135 to 985 ngg(-1) lipid weight (lw) in coastal herring gulls (Larus argentatus) from the marine Hvaler Archipelago (The Glomma River Estuary), Norway. Hexabromocyclododecane (HBCD) concentrations ranged from 10 to 698 ngg(-1)lw. High range in δ(13)C indicates that gulls were subject to a diversity of carbon sources, likely reflecting their mixed feeding on terrestrial and marine organisms, or diversity of autochthonous and allochthonous (watershed) energy sources at the bases of their marine/estuarial food chains. Inverse relationships of HBCD, and to somewhat lesser extent of BDE-209, with δ(13)C values suggest higher abundance of these compounds in the land-derived energy-sources of the gulls. Inverse relationships of BDE-99, BDE-183 and BDE-209 with δ(15)N suggest that trophic relationships affect bioaccumulation of these compounds in the herring gulls, with greater bioaccumulation from lower trophic level prey species. This may be because these PBDE congeners are subject of debromination in higher trophic levels prey species of the gulls (e.g., teleost fish). Levels of BDE-209 (up to 95 ng/g lipid) of these herring gulls from 1998 were in the higher range reported in European birds, and not matched by other reports in North Sea seabirds. The present study suggests that the currently used brominated flame-retardants (BFRs), BDE-209 and HBCD relate to changing nutrient allocation in the herring gulls, and represent a risk to seabirds exploiting near-shore and estuary ecosystems.

Mechanisms of action of two different natural mixtures of persistent organic pollutants (POPs) in ovarian follicles.

The present work investigated the effects of two different natural mixtures on aryl hydrocarbon receptor (AhR) and oestrogen receptor (ER)beta protein levels, as well as on the activity of cytochrome P450 (CYP) 1A1 and CYP2B. Consequently, the authors observed the effects of these mixtures on gonadotropine-stimulated steroid secretion by ovarian follicles. The natural mixtures that were studied were 'Mjosa' extracted from burbot liver, which contains a high level of PBDEs, and 'Marine mix', extracted from Atlantic cod liver, which contains a high level of polychlorinated biphenyls (PCBs). Follicular cells were exposed in vitro to 'Marine mix' and 'Mjosa mix' at doses of 3.6 and 1.4 microg ml(-1), respectively. Media were collected and used for steroid analysis and cell viability assays. Cells were used to estimate aromatase activity (CYP19), AhR and ER protein levels, and CYP1A1 and CYP2B1 activity. Western blot analysis indicated down-regulation of AhR by 'Marine mix' and down-regulation of ERbeta by Mjosa mix. Up-regulation of CYP1A1 expression and activity were seen following treatment with Marine mix, but not Mjosa mix. Increased CYP2B1 activity was noted after treatment with both 'Marine mix' and Mjosa mix. Both mixtures increased luteinizing hormone (LH)-stimulated progesterone and testosterone secretion, follicle-stimulating hormone (FSH)-stimulated oestradiol secretion, and CYP19 activity. These results suggest that: (1) 'Marine mix' is a mixed-type CYP inducer; (2) 'Mjosa mix' is an inducer of ERbeta and CYP2B; and (3) both 'Marine mix' and 'Mjosa mix' stimulate aromatase activity as a consequence of oestradiol secretion through activation of CYP19.

The potential impact of environmental variation on the concentrations and ecological effects of pollutants in a marine avian top predator.

Concentrations of organochlorine contaminants (OCs) and associations between OCs and fitness components were examined in great black-backed gulls (Larus marinus) in three colonies along the coast of northern Norway. In one of the colonies, data were collected in two subsequent seasons. Concentrations of four OCs (HCB, oxychlordane, DDE and PCB) were measured in blood (n=260) and fitness components (reproductive variables and adult return rate between breeding seasons) were recorded. In the first year, in two of the colonies, body condition and reproductive performance among the gulls were poor compared to the third colony, suggesting spatial variation in environmental conditions, especially food availability. However, in the third colony, body condition and reproductive performance were even better in the second season; i.e. environmental conditions varied temporally. OC residues were higher in the colonies where environmental conditions were poor, but much of this variation was explained by differences in body condition among colonies. Moreover, concurrent with improved body condition from one season to the next, the concentrations of OCs were halved. In the two colonies where environmental conditions were poor, female OC residues were negatively related to egg-laying date, egg size and nesting success, and in the colony where the concentrations of OC were highest, gulls with elevated DDE residues had low probability of returning between breeding seasons. In comparison, in the colony where environmental conditions were better in the first year, other types of adverse relationships between OCs and fitness components were found; i.e. chicks from females with high OC concentrations were in poor condition at hatching, suggesting maternal transfer of OCs to the eggs, and males with high OC residues had poor nesting success and chick survival, suggesting OC-mediated behavioural changes. With improved environmental conditions and lower OC concentrations in the second season, no significant adverse relationships between OCs and fitness components were found. This study thus suggests that there are complex interrelationships between both concentrations and ecological effects of OCs, and the environment, indicating that effects of OCs in nature may only be assessed after considering environmental variation.

Spatial and temporal changes of chlorinated pesticides, PCBs, dioxins (PCDDs/PCDFs) and brominated flame retardants in human breast milk from Northern Russia.

This study presents for the first time temporal changes of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Russian human breast milk samples. Concentrations of OCPs and PCBs in samples from three locations in the North West of Russia in 2000-2002 (n=42), were compared to corresponding levels measured in 1993-1996 (n=58). In addition brominated flame retardants (BFRs), consisting of polybrominated diphenylethers (PBDEs) (including BDE-209) and hexabromocyclododecane (HBCD) were analysed in samples from 2000-2002 (n=37). The present levels of SigmaDDTs and SigmaHCHs were 5 and 10 times higher than corresponding levels in the neighbouring country Norway. Median concentrations of SigmaHCHs (196 microg/kg lw), SigmaCHBs (19.7 microg/kg lw) and SigmaPCBs(16) (316 microg/kg lw) were highest in Murmansk. The percentage of p,p'-DDT to SigmaDDTs and ratio DDE/DDT suggest possible ongoing use of DDT in Russia. Levels of PBDE were low and dominated by the congeners BDE-47 and BDE-153. The deca brominated BDE-209 was detected in all analysed samples (median concentration 0.19 microg/kg lipid). Levels of SigmaOCPs and SigmaPCBs decreased 56 and 30% in Murmansk and 36 and 43% in Arkhangelsk during the study period. The decline of SigmaOCPs was significant at both locations (p<0.05-p<0.0001). For SigmaPCBs, the decreasing trend was only significant in Arkhangelsk (p<0.0001). In addition, a decline of Sigmatotal TEQs (SigmaTEQs of PCDDs/PCDFs, non-ortho- and mono-ortho PCBs) was observed in Murmansk and Arkhangelsk during the study period. The exposure of infants by PCDDs/PCDFs and dioxin-like PCBs is still exceeding the daily tolerable intake (TDI) in North West Russia. However, the concentrations of PCDDs/PCDFs and dioxin-like PCBs seem to decline very rapidly.

Polybrominated diphenyl ethers and HBCD in bird eggs of South Africa.

In this paper, the first data on brominated flame retardants (BFRs), in particular polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) in eggs of bird species from South Africa are described (N=43). Concentrations of PBDEs were detected in all the studied species and in all the geographic areas. Highest concentrations of PBDEs were measured in bird eggs from the Vaal River, which is situated downstream of the most industrialized area in South Africa. Sum-PBDE concentrations were highest in eggs of one African sacred ibis (396 ng g(-1) lipid weight (lw)), possibly due to foraging on dumping sites. Lowest mean level of sum-PBDEs (2.3 ng g(-1) lw) was measured in cattle egrets (N=11) from Barberspan Sanctuary, a Ramsar site. The PBDE congener pattern showed large differences, reflecting different trophic levels, migratory behavior, distance to the source, and, exposure to different PBDE mixtures, among others. HBCD was detected only in four species, and highest levels were measured in one egg of African sacred ibis (71 ng g(-1) lw). In most species, levels of PBDEs were one to several orders of magnitude lower than levels of DDTs and PCBs. PBDEs correlated strongly with DDTs, PCBs and some other organochlorines (OCs), indicating the same source. The widespread occurrence of PBDEs in the South African avian species showed a strong need for further investigations of PBDEs in the Southern African environment.

Selective bioaccumulation of chlorinated pesticides and metabolites in Arctic seabirds.

Chlorinated pesticides and metabolites (CPs) were quantified in the seabird species: little auk (Alle alle), Brünnich's guillemot (Uria lomvia), black guillemot (Cepphus grylle) and black-legged kittiwake (Rissa tridactyla). The purpose was to evaluate avian accumulation of selected CPs based on their concentrations and relative patterns, their relation to dietary descriptors (stable isotopes of carbon and nitrogen), to enzymes involved in biotransformation, as well as CPs' accumulation potential relative to the recalcitrant polychlorinated biphenyl PCB-153. In all species, the CP pattern was dominated by p,p'-dichlorodiphenyltrichloroethane (DDE) and hexachlorbenzene (HCB). Except for HCB, concentrations were not related to trophic position. Most CPs were quantified in black guillemot, indicating a slower elimination compared to other seabird species. Brünnich's guillemot showed efficient elimination of chlordanes, whereas the opposite was found for little auk. Kittiwake showed higher accumulation of persistent CP and metabolites than auks, whereas accumulation of less recalcitrant CPs was low.

Levels of toxaphene congeners in white whales (Delphinapterus leucas) from Svalbard, Norway.

This study reports concentrations of three pesticide toxaphene congeners (CHBs; CHB-26, -50 and -62) from the blubber of ten adult, male white whales (Delphinapterus leucas) from Svalbard, Norway. The CHB congeners that occurred at the highest levels in the blubber of the white whales were, as expected, CHB-26 (4636+/-1992 (SD) ng/g l.w.) and CHB-50 (6579+/-2214 ng/g l.w.); CHB-62 (232+/-231 ng/g l.w.) was also present, but at much lower concentrations. The mean level of the sum of the three CHBs (SigmaCHBs = 11,447+/-4208 ng/g l.w.) in this study is more than twice the mean concentrations of the well-known organochlorine (OC) pollutants SigmaDDTs (sum of pp'-DDT, pp'-DDE, pp'-DDD) and SigmaPCBs (sum of 27 PCB congeners) previously reported from the same individual white whales. The concentrations of CHBs in white whales from Svalbard are at the high end of the range for concentrations of these compounds compared to other Arctic white whale populations. Additionally, the contribution of CHBs to the overall OC burden is larger in white whales from Svalbard compared with their counterparts from other areas in the Arctic. Male white whales from Svalbard have several orders of magnitude higher concentrations of SigmaCHBs compared to seals and polar bears (Ursus maritimus) from the same area. The high levels of CHBs in these whales, and their dominance in the OC pattern, suggests that white whales in Svalbard are exposed to high levels of this group of contaminants. Further studies are needed to investigate possible effects of CHBs and other OC contaminants on the white whale population in Svalbard.

Brominated flame retardants (BFRs) in breast milk and associated health risks to nursing infants in Northern Tanzania.

The main aim of this study was to assess brominated flame retardants (BFRs) in breast milk in the Northern parts of Tanzania. Ninety-five colostrum samples from healthy, primiparous mothers at Mount Meru Regional Referral Hospital (MMRRH), Arusha Tanzania, were analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), hexabromobenzene (HBB), (2,3-dibromopropyl) (2,4,6-tribromophenyl) ether (DPTE), pentabromoethylbenzene (PBEB) and 2,3,4,5,6-pentabromotoluene (PBT). The Æ©7PBDE (BDE 28, 47, 99, 100, 153, 154, 183) ranged from below level of detection (

Dioxins, PCBs, chlorinated pesticides and brominated flame retardants in free-range chicken eggs from peri-urban areas in Arusha, Tanzania: Levels and implications for human health.

The environment in the northern part of Tanzania is influenced by rapid population growth, and increased urbanization. Urban agriculture is common and of economic value for low income families. In Arusha, many households sell eggs from free-ranging backyard chicken. In 2011, 159 eggs from different households in five different locations in Arusha were collected, homogenized, pooled into 28 composite samples and analyzed for a wide selection of POPs. Levels of POPs varied widely within and between the locations. The levels of dieldrin and ΣDDT ranged between 2 and 98,791 and 2 and 324ng/g lipid weight (lw), respectively. EU MRLs of 0.02mg/kg dieldrin for eggs were exceeded in 4/28 samples. PCBs, HCHs, chlordanes, toxaphenes and endosulfanes were found at lower frequency and levels. Brominated flame retardants (BFRs), e.g polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD) and 1,2-bis(2,4,6-tribromphenoxy)ethane (BTBPE) were present in 100%, 60% and 46% of the composite samples, respectively. Octa-and deca-BDEs were the dominating PBDEs and BDE 209 levels ranged between

Strain- and sex-specific differences in the glutathione S-transferase class pi in the mouse examined by gradient elution of the glutathione-affinity matrix and reverse-phase high performance liquid chromatography.

A gradient elution with glutathione (GSH) from a GSH-Sepharose 6B affinity column separated the hepatic mouse glutathione S-transferases (GST) to the alpha-, mu- and pi-classes. The GST-dependent conjugation of atrazine and glutathione was catalyzed by a pi-class GST. The pi- and mu-classes were both identified by their respective specific substrates, and after reverse-phase HPLC, by N-terminal analysis of 19-35 of the amino acids. The alpha-class GST was associated with a high selenium-independent GSH peroxidase activity and the purified protein had a N-blocked terminal. Strain related differences in the pi-class GST of the CD-1, C57BL/6, DBA/2 and Swiss-Webster males were observed by PhastGel electrophoresis of the GSH affinity chromatograph separated fractions, reverse phase HPLC and by N-terminal amino acid sequence analysis.

The separation and identification of glutathione S-transferase subunits from Orthosia gothica.

Four subunits of the cytosolic glutathione S-transferase (GST) in Orthosia gothica fed on willow leaves and a semisynthetic bean diet were purified as separate peaks (subunits 1-4) by a two-step gradient elution from a reverse-phase HPLC column after an initial purification by glutathione-Sepharose 1-chloro-2,4-dinitro-benzene (CDNB). Subunit 1 with a molecular weight of 26.0 kDa reconstituted into a GST homodimer with an isoelectric point of 4.8 and the N-terminal amino acid sequence (27 steps) indicated a relationship to the class theta GST of Musca domestica in the first 10 steps (50% homology), but also to the GST class pi of Caenohrabditis elegans (50% between steps 10 and 20). The three subunits 2-4 all had a molecular weight of 23.5 kDa and the isoelectric points of the reconstituted homodimers were > 9.0. The N-terminal amino acid sequence was determined (24 steps) and was identical for the three subunits. A high identity of sequence to the GST in C. elegans (70% between steps 1 and 17), and a low homology (25%) to the O. gothica subunit 1 was observed. Thus, we suggest the O. gothica subunit 1 belong to a different class (O. gothica GST class 1) of GST than subunits 2-4 (O. gothica GST class 2). When the larvae hatched and fed on a semisynthetic bean diet, subunits 3 and 4 were not present in the HPLC eluate, and the subunit 2/subunit 1 ratio increased compared to the corresponding ratio in the larvae which hatched and fed on willow leaves until the third instar.

Behavioural hyperactivity in rats following postnatal exposure to sub-toxic doses of polychlorinated biphenyl congeners 153 and 126.

Rats were exposed through mother's milk either to the di-ortho-substituted polychlorinated biphenyl (PCB) congener 2,2',4,4',5,5'-CB (IUPAC no. 153) or to the non-ortho-substituted PCB congener 3,3',4,4',5-CB (IUPAC no. 126). The different groups of mothers were dosed via gavage with corn oil vehicle, 5 mg/kg b.w. of PCB 153 or 2 microg/kg b.w. of PCB 126 every second day from day 3 to 13 after delivery. The exposure did not affect the body weight (b.w.) of the dams or the physical development of the pups. A two-component schedule of reinforcement was used to study behavioural effects of the PCB exposures in male offspring. One component was operating when the house light was turned on. Then a reinforcer, a drop of water, was delivered every 2-min. This component is called a 2-min fixed interval (FI) schedule of reinforcement. The other component was in effect when the house light was turned off. Then no reinforcer was ever delivered. This is called an extinction (EXT) component. It was shown that the PCB-exposed offspring were hyperactive as they had an increased frequency of lever presses. In addition, the PCB 153-exposed male pups showed a behavioural pattern similar to that observed in spontaneously hypertensive rats (SHR), an animal model of attention-deficit hyperactivity disorder (ADHD). This behaviour is characterized by 'burst' of lever presses with short interresponse times (IRT) just before the next reinforcer is given. These results show that both PCBs 153 and 126 may produce significant neurotoxic effects following postnatal exposure through mother's milk.

Effect of 1,1'-(2,2,2-trichloroethylidene)-bis(4-chlorobenzene) (DDT) on gap junctional intercellular communication and morphological transformation of Syrian hamster embryo cells.

The organochlorine insecticide 1,1'-(2,2,2-trichloroethylidene)bis(4-chlorobenzene) (DDT) did not induce or promote induction of morphological transformation in Syrian hamster embryo (SHE) cells, but it was a potent inhibitor of gap junctional intercellular communication (GJIC). The kinase inhibitor staurosporine did not affect DDT induced inhibition of GJIC, although it has been shown to decrease the inhibitory effect of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on GJIC. In addition, pretreatment with TPA made the cells refractory to further TPA induced inhibition of GJIC, while they remained sensitive to DDT. Thus, DDT and TPA inhibit GJIC through different mechanisms. Elevation of cellular cyclic adenosine monophosphate (cAMP) level by exposure to forskolin counteracted the inhibitory effect of DDT similar to that observed for TPA. Continuous exposure to DDT at concentrations near the effective concentration (50%) value (EC50 value) resulted in a slight recovery of GJIC following the initial inhibition. This recovery was not accompanied by the cells becoming refractory to further DDT induced inhibition of GJIC. The recovery of GJIC after removal of the DDT containing medium seemed to be related to a reduction in the amount of cell-associated DDT.

Effects of DDT on paracetamol half-life in highly exposed mothers in Zimbabwe.

After assessment of the levels of DDT residues in the milk samples, 1 g paracetamol was administered p.o. to 28 breastfeeding mothers selected from a population of 116, according to DDT residues in their milk (the 14 with the highest values and the 14 least exposed). Post dose blood samples were taken from the basilic veins of the mothers at time intervals up to 4 h, post dose. The paracetamol blood concentrations were determined. A significantly shorter paracetamol half-life was found in mothers with higher DDT body burden, who also exhibited lower paracetamol concentrations in blood. The results highlighted concern for the highly exposed mothers taking paracetamol (NSAID) as an analgesic, or as an antipyretic.

Organochlorines in top predators at Svalbard--occurrence, levels and effects.

Alarmingly high polychlorinated biphenyl (PCB) levels have been found in the top predators such as glaucous gull (Larus hyperboreus) and polar bear (Ursus maritimus) at Svalbard [Gabrielsen, G.W., Skaare, J.U., Polder, A., Bakken, V., 1995. Chlorinated hydrocarbons in glaucous gull (Larus hyperboreus). Sci. Total Environ. 160/161, 337-346; Bernhoft, A., Skaare, J.U., Wiig, O., 1997. Organochlorines in polar bears (Ursus maritimus) at Svalbard. Environ. Pollut. 95, 159-175; Henriksen, E.O., Gabrielsen, G.W., Trudeau, S., Wolkers, H., Sagerup, K., Skaare, J.U., 1999. Organochlorines and possible biochemical effects in glaucous gull (Larus hyperboreus) from Bear Island, the Barents Sea. Arch. Environ. Contam. Toxicol. (in press). ]. Studies of the possible toxic effects, particularly on the immune system and reproduction, of the very high PCB levels in these species are currently being investigated. Data obtained in the field (f.i. reproductive success in polar bears and intestinal nematodes in glaucous gulls), as well as levels of various biochemical and physiological parameters (f.i. thyroid hormones, retinol, EROD activity, CYP1A, IgG), have been coupled with the PCB levels [Skaare, J.U., Wiig, O., Bernhoft, A., 1994. Klorerte organiske miljogifter; Nivâer og effekter i isbjorn. Norwegian Polar Institute Reportseries no. 86, 1-23 (in Norwegian); Bernhoft, A., Skaare, J.U., Wiig, O., 1997. Organochlorines in polar bears (Ursus maritimus) at Svalbard. Environ. Pollut. 95, 159-175; Bernhoft, A., Skaare, J.U., Wiig, O., Derocher, A.E., Larsen, H.J., 2000. Possible immunotoxic effects of organochlorines in polar bears (Ursus maritimus) at Svalbard (in press); Henriksen, E.O., Gabrielsen, G.W., Skaare, J.U., Skjegstad, N., Jensen, B.M., 1998a. Relationship between PCB levels, hepatic EROD activity and plasma retinol in glaucous gull, Larus hyperboreus. Marine Environ. Res. 46, 45-49; Henriksen, E.O., Gabrielsen, G.W., Trudeau, S., Wolkers, H., Sagerup, K., Skaare, J.U. , 1999. Organochlorines and possible biochemical effects in glaucous gull (Larus hyperboreus) from Bear Island, the Barents Sea. Arch. Environ. Contam. Toxicol. (in press); Sagerup, K., Gabrielsen, G.W., Skorping, A., Skaare, J.U., 1998. Association between PCB concentrations and intestinal nematodes in glaucou gulls, Larus hyperboreus, from Bear Island. Organohalogen compounds 39, 449-451; Skaare, J.U., Wiig, O., Bernhoft, A., 1994. Klorerte organiske miljogifter; Nivâer og effekter i isbjorn. Norwegian Polar Institute Reportseries no. 86, 1-23. (in Norwegian)].

Possible immunotoxic effects of organochlorines in polar bears (Ursus maritimus) at Svalbard.

Associations between immunoglobulin G (IgG) levels and the organochlorine contaminants (OCs) polychlorinated biphenyls (PCBs), chlordanes, 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE), hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs) in blood plasma from polar bears caught at Svalbard were determined. The blood samples were collected from free-living polar bears of different age and sex between 1991 and 1994. The IgC concentration increased with age and was significantly higher in males than in females. IgG was negatively correlated with sigmaPCB level and with three individual PCB congeners, IUPAC numbers 99, 194, and 206. HCB was also negatively correlated with IgG. The significant negative OC correlation with IgG levels may indicate an immunotoxic effect.

Relationships between plasma levels of organochlorines, retinol and thyroid hormones from polar bears (Ursus maritimus) at Svalbard.

Associations were determined between retinol and the thyroid hormones thyroxine (T4) and triiodothyronine (T3), respectively, and the organochlorine contaminants (OCs) polychlorinated biphenyls (PCBs), 1, 1-dichloro-2,2-bis-(4-chlorophenyl)ethylene (DDE), hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs) in blood plasma from polar bears (Ursus maritimus) caught at Svalbard. The blood samples were collected from free-ranging polar bears of different age and sex in 1991-1994. The retinol concentration and the ratio of total T4 (TT4) to free T4(FT4) (TT4/FT4 ratio) decreased linearly with increasing concentrations of PCBs and HCB. Retinol was also negatively associated with HCHs, while the TT4/FT4 ratio was positively associated with DDE. The concentrations of retinol and thyroid hormones were significantly higher in females than in males. However, the TT4/FT4 and TT3/FT3 ratios were significantly higher in males than in females. The concentrations of thyroid hormones were negatively correlated with age in male bears, while in females, thyroid hormones did not change with age. The OCs were found to explain 12, 30, and 7% of the variation of retinol concentrations and the TT4/FT4 and TT3/FT3 ratios, respectively, after correcting for age and sex. The potential consequence of these associations for the individual and the population is unknown.

Levels of selected individual polychlorinated biphenyls in different tissues of harbour seals (phoca vitulina) from the Southern coast of Norway.

Concentrations of individual polychlorinated biphenyls (PCBs) were determined in blubber, liver, kidney and brain tissues of 10 male harbour seals (Phoca vitulina) of different ages. The animals were found dead or dying on the southern coast of Norway in 1988 during the morbilli virus epizootic. Twenty-three PCB congeners were investigated in all tissues by capillary gas chromatography with electron capture detection and comparison with standards of the respective congeners (IUPAC numbers 28, 52, 74, 99, 101, 105, 110, 114, 118, 128, 138, 141, 149, 153, 156, 157, 170, 180, 183, 187, 194, 206 and 209). In addition, three toxic coplanar congeners (IUPAC numbers 77, 126 and 169) were investigated in the blubber samples. Total PCB (sum of the determined congeners) in kidney (12-60 nmol g(-1)), liver (12-90 nmol g(-1)) and blubber (10-79 nmol g(-1)) were similar on extractable lipid basis, while total PCB in brain lipid was about 1/10 (1.6-12 nmol g(-1)). The absolute concentrations of the individual congeners in brain lipid correlated poorly with the respective concentrations in each of the other tissues, while the individual congener concentrations in the lipid fractions of kidney, liver and blubber tended to correlate with each other. The relative concentrations of the sum of the most persistent congeners (PCB-99, -128, -138, -153, -170, -180, -187 and -194) correlated in all tissues, and an increase of the relative concentrations of these congeners, most distinct in blubber, with higher carcass weight, was shown. Also, total PCB in blubber correlated with carcass weight. When comparing the relative concentration patterns of individual congeners (per cent of total) in the four tissues, six congeners differed significantly between tissues, and the relative brain concentrations showed most deviation from the other tissues. The concentration of the coplanar PCBs was 1 : 1000-1 : 1000 of the total PCB concentration. The results demonstrate a lower accumulation together with a different concentration pattern in the brain as compared to other tissues.