Enshi (E 108°23′12″ - 110°38′08″, N 29°07′10″ - 31°24′13″) is a national minority autonomous prefecture and located in Northwestern Hubei Province, China. From early 1930 to 1960, people living in Yutangba, Huabei and Shadi villages of Enshi, experienced loss of hair and nails, showing the typical symptoms of Se toxicity. For instance, 19 of 23 local inhabitants in Yutangba showed visible Se poisoning symptoms and all livestock in the village died in 1963. Subsequently, villagers were evacuated from their homes in Yutangba. Selenium mines has been discovered in Yutangba village, with a high Se content of 8500 mg/kg. The Se mines were formed during Maokou, Late Permian period with a thickness of 13 meters, which were the “culprits” for the selenosis observed in the Yutangba village.