Levels and enantiomeric signatures of methyl sulfonyl PCB and DDE metabolites in livers of harbor porpoises (Phocoena phocoena) from the Southern North Sea

The concentration of 26 methyl sulfonyl metabolites of polychlorinated biphenyls (MeSO2-PCBs) and of p,p'-DDE (MeSO2-DDE) were determined in 19 liver samples from harbor porpoises (Phocoena phocoena) stranded between 1997 and 2000 on the Belgian and French North Sea Coasts. The total concentration of MeSO2-PCBs ranged from 39 to 4221 ng/g lipid weight (lw) and were generally higher in adults (age > 2 yr, range 969-4,221 ng/g lw) than in juveniles (age < 2 yr, range 39-1815 ng/g lw). The concentrations of MeSO2-DDE were generally also higher in adults (21-96 ng/g lw) than in juveniles (0.5-60 ng/g lw). Congeners 3- and 4-MeSO2-CB101 were the dominating metabolites in all samples. Due to their preferential retention in the liver, the MeSO2-PCB congeners could be divided into two groups. The first group was dominated by the 3-MeSO2-PCB congeners and consisted of MeSO2-CB31, -CB49, -CB52, -CB87, and -CB101, which all have a 2,5-chlorine substitution in the phenyl ring containing the methyl sulfonyl group. The second group was dominated by the 4-MeSO2-PCB congeners and consisted of MeSO2-CB64, -CB91, -CB110, and -CB132, which all have a 2,3,6-chlorine substitution. The ratios of sum of PCBs/sum of MeSO2-PCBs and p,p'-DDE/MeSO2-DDE differed greatly between individual subjects and ranged from 15 to 419 and from 17 to 1088, respectively. The ratio between the precursor PCB congeners and their corresponding metabolites ranged from 0.6 (CB49) to 175 (CB174). Enantiomeric fractions (EFs) for MeSO2-PCB atropisomers, which include 3-MeSO2-CB132, 3-MeSO2-CB149, 4-MeSO2-CB149, 3-MeSO2-CB174, and 4-MeSO2-CB174, were also measured in 8 out of the 19 subjects. High enantiomeric excess (EF > 0.73 or EF < 0.23) for the measured chiral MeSO2-PCB congeners was found in all samples. This result may suggest that one atropisomer may be preferentially formed in harbor porpoises or that the atropisomers are retained in a highly selective manner.

Enantiomeric signatures of chiral polychlorinated biphenyl atropisomers in livers of harbour porpoises (Phocoena phocoena) from the southern North Sea

The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers, including PCB 95, PCB 149 and PCB 132, was measured in 11 livers of harbour porpoises (Phocoena phocoena) from the southern North Sea. Non-racemic enantiomeric ratios (ERs) were found in some samples. The value of ERs in three of the four juvenile porpoises was equal or almost equal to one, while the ERs in all adults differed from racemic and ranged from 1.31 to 2.54 for PCB 95; from 1.19 to 1.81 for PCB 149 and from 0.45 to 0.94 for PCB 132. There were no relationships between the total concentration of PCBs and ERs. To understand the phenomena, the relationships between the ER value of individual chiral congener with age, concentration of total PCBs and PCB congener pattern were discussed. A model of intake and elimination kinetics was set up and it was tested using the ratio between concentration of PCB 153 and PCB 101 in the liver samples. There was a clear trend between the enantiomeric ratios and the ratio between PCB 153 and PCB 101. Considering that PCB 153 is one of the most persistent PCB congeners in marine mammals and PCB 101 is a relatively easy metabolised congener, this trend means that the enantiomeric ratio most likely reflects the proportion of the metabolised congener. The exposure period in contaminated conditions has a strong impact on ERs, and it is suggested that ERs in wildlife, combined with information on their anthropometric data, health status, diet and habitat conditions, might be good indicators of pollution in coastal ecosystems.

Immunologic and other biological parameters as a function of smoking status and of residence in areas differing in terms of air pollution

In the industrial region of La Louvière (Belgium), healthy persons, presenting at a consultation of preventive medicine, showed differences as a function of smoking and of residence in one of four areas differing in sources of emissions, population density and green zones. Smokers had significantly (P</=0.05) more leukocytes microl(-1), neutrophils microl(-1), CD3+ lymphocytes (lys) microl(-1), CD4+ lys microl(-1), CD25+ lys microl(-1), higher CD4/CD8 ratio's and higher carcino-embryonic antigen serum levels but significantly lower IgG immunoglobulin and serum carotene levels than non-smokers. Compared to persons living in the 'Peripheral area', and after correction for sex, smoking status and age, persons living in the more polluted areas showed significantly more CD3+CD56+ lys microl(-1). Although about the same mean value for the CD4/CD8 ratio was found for the more polluted areas, a higher percentage of their residents showed a ratio that was either <1 or >/=2.25, significantly so for the Power Station-Landfill area. A non-significant but consistent trend towards higher lymphocyte and CD8 lys counts and higher complement C3c serum levels further suggested an association between residence in a more polluted area and immunologic features. The number of CD3+CD56+ lys microl(-1), reported to be increased in cancer patients, showed a negative correlation with the CD4/CD8 ratio (r(2)=0.132, P<0.0001).