It discusses chemi cal forms, availability and biogeochemical cycle of selenium, and also analyses the relations between selenium and endemic disease and its important role in env ironment.

• 讨论了硒的形态及影响其生物有效性的因素、硒的生物地球化学循环；分析了硒与地方病的关系以及它在生态环境中所起的重要作用。