Physiologically-based pharmacokinetic modelling of immune, reproductive and carcinogenic effects from contaminant exposure in polar bears (Ursus maritimus) across the Arctic

摘要: Polar bears (Ursus maritimus) consume large quantities of seal blubber and other high trophic marine mammals consequently have some the highest tissue concentrations organohalogen contaminants (OHCs) among Arctic biota. In present paper we carried out a risk quotient (RQ) evaluation on OHC-exposed polar harvested from 1999 to 2008 11 circumpolar subpopulations spanning Alaska Svalbard in order evaluate OHC-mediated reproductive effects (embryotoxicity, teratogenicity), immunotoxicity carcinogenicity (genotoxicity). This RQ was based Critical Body Residue (CBR) concept Physiologically-Based Pharmacokinetic Modelling (PBPK) approach using OHC measured bear adipose or liver tissue. The range within populations were as follows for adipose, sum polychlorinated biphenyls ∑PCBs (1797-10,537 ng/g lw), methylsulphone-PCB ∑MeSO2-PCBs (110-672 chlordanes ∑CHLs (765-3477 α-hexachlorocyclohexane α-HCH (8.5-91.3 β-hexachlorocyclohexane β-HCH (65.5-542 chlorbenzenes ∑ClBzs (145-304 dichlorodiphenyltrichloroethane ∑DDTs (31.5-206 dieldrin (69-249 polybrominated diphenyl ethers ∑PBDEs (4.6-78.4 lw). For liver, perfluorooctanesulfonic acid (PFOS) ranged 231-2792 ww. total additive all OHCs 4.3 28.6 East Greenland reproduction, immune health carcinogenicity, highlighting important result that toxic effect threshold (i.e. RQ>1) exceeded assessed. PCBs main contributors three categories, contributing 70.6% 94.3% between 3.8-22.5. second contributor immunological (0.17