摘要：A subacute poisoning, called Yusho, which occurred in Japan in 1968, was caused by the ingestion of specific lots of Kanemi rice bran oil which had been accidentally contaminated with large amounts of Kanechlor 400 (a commercial preparation of PCB mixture with a chlorine content of about 48%). During this decade, most of the clinical symptoms of Yusho has diminished gradually along with a decrease in PCB levels in the blood of patients. However, some of them such as subcutaneous cyst formation, pigmentation of the skin, eyelid and gingiva, eye discharge and abnormal changes of the tarsal gland were still continuing in relatively small number of the severe grade patients. Since the additional contaminants, polychlorinated dibenzofurans (PCDF) and polychlorinated quaterphenyls (PCQ), were also detected in the causal oil, their synergetic effects on the PCB poisoning have become of great concern to understand the etiology of Yusho. In this paper, studies for Yusho during these ten years were briefly reviewed dividing in the following chapters ; (1) Toxic compounds in the rice bran oil, (2) Alterations in the clinical symptoms of Yusho, (3) Relationship between the gas chromatographic patterns and levels of PCBs in the blood and the clinical symptoms, (4) Toxicological assessments of PCBs and PCDFs and (5) Treatments for Yusho.
