Yushō disease
'oil symptoms') was a mass poisoning by polychlorinated biphenyls (PCBs) which occurred in northern Kyūshū, Japan, in 1968.
[1][2][3] In January 1968, rice bran oil produced by Kanemi Company in Kyushu was contaminated with PCBs and polychlorinated dibenzofurans (PCDFs) during production.
The contaminated rice bran oil was then sold to poultry farmers for use as a feed supplement and to consumers for use in cooking.
[5] Common symptoms included dermal and ocular lesions, and a lowered immune response.
[1] Scientists discovered that low levels of PCBs could kill fish and other wildlife and as such their use in manufacturing was reduced.
The PCB that was used as the heating medium leaked from the pipes and mixed into the rice bran oil.