Concentrations of PCBs, PCDFs and PCDDs in the blood of Yusho patients and their toxic equivalent contribution.

Yusho blood and control serum were collected in around 1991 and analyzed for congeners of PCDDs, PCDFs and PCBs. In Yusho blood, TEQ was mainly contributed by 2,3,4,7,8-penta-CDF (77-248 ppt), 1,2,3,4,7,8-hexa-CDF (15-37 ppt) and 2,3,3',4,4',5-hexa-CB (16-77 ppt). Total TEQ in Yusho blood (185-441 ppt) was only 3-14 times higher than that of control serum (31-61 ppt). It is notable that the concentrations of 3,3',4,4',5-, 2,3,3',4,4'- and 2,3',4,4',5-penta-CBs in Yusho blood were comparable to or lower up to 3-5 times than those in control blood.