Levels and chiral signatures of persistent organochlorine pollutants in human tissues from Belgium

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in human tissue samples including muscle, liver, brain, and kidney. The samples were obtained at autopsy in 2000–2001 from three women and eight men from Belgium, aged between 5 and 76 years. The measured PCBs included 23 ortho-substituted congeners and 3 non-ortho-substituted congeners (PCB 77, PCB 126, and PCB 169). The mean concentrations of ΣPCBs were 29.4, 35.3, 10.6, and 11.8 ng/g wet wt in liver, muscle, kidney, and brain, respectively. HCB, γ-HCH, β-HCH, p,p′-DDE, and p,p′-DDD were found in all samples, while p,p′-DDT could only be found in one liver sample. The most abundant pesticide was p,p′-DDE. PCB 153 and PCB 180 were the main ortho-substituted congeners found in all the samples, while the concentration of the congeners with less than three chlorine atoms was below the limit of determination. In 10 of 18 tissues, the concentrations of PCB 169 were higher than the concentration of PCB 126. These results are consistent with the order of half-life of these congeners in humans and indicate that a steady state had been reached in these subjects. The enantiomeric compositions of α-HCH and chiral PCBs, including PCB 95, PCB 132, and PCB 149, were also measured. α-HCH was found to be racemic in three liver samples, while chiral PCB 95, PCB 149, and 132 showed racemic or nearly racemic compositions in muscle, kidney, and brain. Higher enatiomeric ratios (ERs) for the three chiral PCBs were found in liver samples. The mean (range) ERs in liver were 1.69 (1.04–2.97), 1.16 (0.99–1.41), and 0.74 (0.48–0.97) for PCB 95, PCB 149, and PCB 132, respectively.