Ecological Aspects of Selenosis on Rangelands

Abstract

Plants containing high concentrations of selenium (Se) have long been recognized for their toxic effects on animals. Marco Polo, traveling in China in 1295, was probably describing signs of Se poisoning when he wrote that the hooves of his livestock became swollen and dropped off when they grazed plants growing in certain areas (Rosenfeld and Beath 1964). Loss of hair and nails in humans, presumably suffering from chronic Se ingestion was described in Colombia by Father Simon Pedro in 1560 [National Research Council (NRC) 1976, 1983]. Guang-Qi (1987) has also described and illustrated chronic selenium toxicosis in some Chinese people