POLYCHLORINATED-BIPHENYLS IN SMALL MAMMALS FROM CONTAMINATED LANDFILLSITES

PCBs in small mammals living in a contaminated landfill site varied in both concentration and congener composition, reflecting both the feed ing strategy of each species and the chlorination of the congeners. Bo dy concentrations of Sigma PCB on a 1:1:1 Arochlor (1242:1254:1260) ba sis gave a rank order of Sorer araneus much greater than Apodemus sylv aticus > Microtus agrestis. Comparisons with data for other PCB-contam inated sites suggest that the Sigma PCB values in S. araneus from the landfill site may be of sufficient magnitude to inhibit reproductive c apability and to cause other major organ dysfunction. There were also inter-specific differences in the whole body concentrations of the ind ividually quantified congeners. For S. araneus, the rank order of conc entrations of the selected ICES 7 marker PCB congeners was: No. 153 > 138 much greater than 180 > 118 much greater than 28 > 101 > 52. In M. agrestis the rank order was: No. 28 > 118 > 153 > 138 > 180, 52 > 101 . The congener order for A. sylvaticus differed from both S. araneus a nd M. agrestis, but was more similar to the latter, being: No. 153 > 1 38 > 118 > 180 > 28 > 52, 101. The contribution of the different conge ners to Sigma PCB in the mammals reflects the degree of chlorination o f different congeners but varies with feeding strategy of the species. In the insectivorous S. araneus, heavily chlorinated congeners (Nos 1 53, 138 and 180) are most abundant, whereas the herbivore, M. agrestis showed congeners Nos 28 and 118 to be present in the highest amounts, whilst the equivalent pattern for the more omnivorous A. sylvaticus w as intermediate between S. araneus and M. agrestis. The high concentra tions of PCBs in S. araneus relative to the other species, suggests th at it may serve as a useful biomarker of terrestrial environmental pol lution by organochlorines. Copyright (C) 1996 Elsevier Science Ltd.