[Accumulation of hydroxylated PCB metabolites in blood]

In order to investigate some potential accumulate properties of hydroxylated PCB metabolites, blood and tissues such as livers, kidneys, lungs and adipose tissue from rats exposed to a commercial PCB (Aroclor 1254) were analyzed for hydroxylated PCBs (OH-PCBs). A large number of OH-PCBs were detected in the liver 1 day after exposure among which almost 13 have been identified in the blood. OH-PCBs were retained selectively in the blood probably due to binding between the OH-PCBs and a protein in serum. One major OH-PCB determined in rat blood was 4-OH-2', 3, 3', 4', 5-pentaCB formed from 2, 3, 3', 4, 4'-pentaCB after NIH shift. Blood of a grey seal from the Baltic also contained at least 8 OH-PCB congeners with 2 major compounds determined as 4-OH-2', 3, 3', 4', 5-pentaCB and 4-OH-2, 3, 3', 4', 5, 5'-hexaCB. Thus, 4-OH-2', 3, 3', 4', 5-pentaCB is the most retainable OH-PCB congener in blood from rats and seal. Human serum have also been found to contain a few number of OH-PCBs at concentration of 0.6 ng/g serum which corresponds to one fourth of PCB level.