Academic journal article Environmental Health Perspectives

Hydroxylated PCB Metabolites and PCBs in Serum from Pregnant Faroese Women. (Articles)

Academic journal article Environmental Health Perspectives

Hydroxylated PCB Metabolites and PCBs in Serum from Pregnant Faroese Women. (Articles)

Article excerpt

In the Faroe Islands in the North Atlantic, the traditional diet includes pilot whale meat and blubber and other marine food. Fatty fish and blubber of mammals may contain high concentrations of organohalogen substances (OHSs). Elevated levels of OHSs have been reported from the Faroe Islands, first documented in breast milk samples obtained in 1987. The aim of this study was to determine the concentrations of hydroxylated polychlorinated biphenyls (OH-PCBs) and polychlorinated biphenyls (PCBs) in serum samples from pregnant Faroese women known to differ in their dietary habits. High concentrations of OH-PCBs and PCBs were found in part of the human serum samples analyzed, and the relative OH-PCB and PCB congener distributions were similar to those observed elsewhere. There was a wide span between the lowest and highest OH-PCB and PCB concentrations in the serum samples analyzed, with ranges of 19-1,800 ng/g lipid weight (lw) and 150-22,000 ng/g lw, respectively. The ratio of [SIGMA]OH-PCB/[SIGMA]PCB averaged about 10% and varied little. 4-Hydroxy-2,2',3,4',5,5',6-heptachlorobiphenyl was the most abundant OH-PCB metabolite in all samples analyzed, with four other OH-PCB congeners as dominating metabolites in the serum. More than 25 additional OH-PCBs were indicated. This study confirms the presence of high concentrations of organohalogen substances in populations or areas far removed from their sources. Key words: Faroe Islands, marine foods, polychlorinated biphenyls, polychlorobiphenylols, pregnancy. Environ Health Perspect 110:895-899 (2002). [Online 26 July 2002] http://ehpnet1.niehs.nih.gov/docs/2002/110p895-899fangstrom/abstract.html

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Polychlorinated biphenyls (PCBs) remain an important class of environmental contaminants even though major legislative measures were taken by most industrialized countries in the early 1970s to stop their production and to restrict most their uses thereof (1). 2,2-Bis (4-chlorophenyl)-1,1,1-trichloroethane (4,4'-DDE) and persistent PCB congeners are in general and still the most abundant pollutants in wildlife and humans, although recent decreases have been reported (2,3). High concentrations of these substances have been determined even in populations living in remote areas (4,5), including people from the Faroe Islands, as first documented by analyses of four pools of human breast milk sampled from a birth cohort in 1987 (6). Similarly high PCB and 4,4'-DDE concentrations were obtained from a second Faroese birth cohort from 1994 (7). People who have a high consumption of fatty fish and live closer to the sources of contamination have high levels of PCBs and DDE (8).

Halogenated phenolic compounds (HPCs) are known to be strongly retained in human and wildlife blood (9), and these metabolites may be present in concentrations only slightly lower than those of the parent compounds (10-12). Among those compounds, a large number of polychlorobiphenylols (OH-PCBs) have earlier been reported in blood from humans, birds, seals, and polar bears (9-17). The concentration of the OH-PCBs may exceed 10% of the total PCB concentration in human serum (5,9,12). As many as 38 OH-PCBs have been identified in human plasma (10), but only a few of these make up the major proportion of the OH-PCB concentrations in the human blood. OH-PCBs are formed via cytochrome P450-mediated oxidation of individual PCB congeners, and those being retained in the blood are metabolites of those that are most strongly accumulated in lipids--the most persistent PCB congeners. Several of the OH-PCBs compete with thyroxine ([T.sub.4]) for its binding to transthyretin (TTR) (18). One of the major OH-PCBs, 2,3,3',4',5-pentachloro-4-biphenylol (4-OH-CB107), which has been identified in human blood (9), appears to possess adverse endocrine-related toxicity (19). OH-PCB metabolites are generally more hydrophilic than the parent compound and are therefore more easily eliminated from the body than their parent PCB congeners. …

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