Yusho disease, which literally means oil disease, is due to PCB poisoning. In 1968, a mass poisoning caused by PCBs occurred in northern Kyushu, Japan. A similar case that occurred in Taiwan was known as Yu-Cheng disease.
Affected individuals experience dermal and ocular lesions, low immune responses, and irregular menstrual cycles. They may also experience unusual skin sores, fatigue, headache, and cough. Reports also show that affected children have poor cognitive development.
In January 1968, the Kanemi Company in Kyushu, Japan produced rice bran oil, which was contaminated with polychlorinated biphenyls and polychlorinated dibenzofurans. The contaminated product was sold to poultry farmers to be used as a feed supplement. It was also sold to consumers for cooking. However, farmers reported that their poultry have difficulty breathing and dying after being fed with the contaminated rice bran oil.