Serum antioxidant levels in Yusho victims over 30 years after the accidental poisoning of polychlorinated biphenyls in Nagasaki, Japan.

Over 30 years have passed since the accidental polychlorinated biphenyls (PCB) poisoning in Japan and yet high concentrations of PCB are still detected in the serum of the victims. PCB produces superoxide and thus victims of PCB poisoning are in a persistent state of oxidative stress. To examine the antioxidative state, we measured the serum concentrations of Cu, Zn-superoxide dismutase (SOD) and Mn-SOD in 38 victims and 20 age-matched control subjects. The mean serum concentration of Cu, Zn-SOD was significantly lower and that of Mn-SOD higher than those of the control. Such an antioxidative state is indicative of an imbalance of Redox regulation mechanism. Persistence of imbalance could result in serious ailments in the future.