PCB and PCDF Congeners in the Blood and Tissues of Yusho and Yu-Cheng Patients

Polychlorinated biphenyl (PCB) poisonings occurred in western Japan, where it is called Yusho, in 1968, and in central Taiwan, where it is called Yu-Cheng, in 1979. The average concentrations of PCBs in the adipose tissue, liver and blood of Yusho patients and in the blood of Yu-Cheng patients were 1.9 ppm, 0.08 ppm, 6.7 ppb and 99 ppb, respectively. Seven PCB congeners, such as 2,4,5,3',4'-pentachloro-, 2,3,4,3',4'-pentachloro-, 2,4,5,2',4',5'-hexachloro-, 2,3,4,2',4',5'-hexachloro-, 2,3,4,5,3',4'-hexachloro-, 2,3,4,5,2',4',5'- heptachloro- and 2,3,4,5,2',3',4'-heptachloro biphenyls were identified in the blood and tissues of patients with Yusho and Yu-Cheng and controls. The concentration of 2,3,4,5,3',4'-hexachlorobiphenyl was comparatively higher in the patients than in controls. The concentrations of polychlorinated dibenzofurans (PCDFs) in the adipose tissue and liver of Yusho patients were 6 to 13 ppb and 3 to 25 ppb, respectively, while no PCDFs were detected in the controls. Major PCDF congeners identified in the tissues and blood of Yusho and Yu-Cheng patients were the 2,3,6,8-tetrachloro-, 2,3,7,8-tetrachloro-, 1,2,4,7,8-pentachloro-, 2,3,4,7,8-pentachloro- and 1,2,3,4,7,8-hexachlorodibenzofurans (DFs), of which the 2,3,4,7,8-pentachloro compound was predominant. Some of the major peaks of the PCB methylthio and methylsulfone derivatives were identical in gas chromatographic retention times with those of 4-methylthio- and 4-methylsulfone-2,5-2',5'-tetrachlorobiphenyl PCDFs, especially 2,3,4,7,8-pentachloro DF, appear to be mainly responsible in the poisonings.