[Yearly and seasonal fluctuation of PCB concentration in skin surface lipid]

PCB concentrations in the skin surface lipids of Yusho patients had been examined for 6 years (in July, 1990-1995). The concentrations in each patients showed a little fluctuation every year. It suggests that the cutaneous sebaceous system is one of the excretory systems of PCB. In 1995, measurement of PCB was performed also in October. The mean concentration of PCB was lower than that measured in Summer (692.7 ng/g in July versus 633.3 ng/g in October, p < 0.05). To explain the fluctuation, seasonal change of sebum composition should be examined.