[Concentration changes in PCB isomers in the blood in patients with PCB poisoning]

The blood of 3 yu-cheng patients sampled from 1980 to 1985 and of 14 yusho patients sampled from 1982 to 1988 were analyzed for 7 polychlorinated biphenyl (PCB) isomers by gas chromatography with a capillary column. The concentrations of PCBs in yu-cheng patients were up to 400 ppb and much higher than those of yusho patients. The high concentration of PCBs were decreased at biological half lives of about 50 months and 2,4,3',4'-tetra-CB and 2,4,5,3',4'-penta-CB were first decreased with time at half lives of about 12 months. Therefore, peculiar gas chromatographic pattern for yusho patients would be formed 3 years after the onset. The concentration and patterns of blood PCBs of yusho patient kept in similar levels during 1982 to 1988.