Selenium
Selenium toxicity due to pollution of environment has been reported in animals. Contamination of pasture from industries emitting fly ash particularly form soft coal may cause selenium poisoning in grazing animals. In 1980-89, poisoning characterized by alopecia and foot scaling, was reported in pigs in China due to use of selenium rich stone coal by farmers for fumigation of soil and as fertilizers. Relationship between selenium toxicity and plant selenium level has been established and selenium excess was considered as one of the factors causing Dengnala disease that affected thousands of cattle and buffaloes in India and Pakistan.