[Analysis of trace elements in cataractous lenses and environmental samples in Tibet]

Trace elements of Cu, Fe, Zn, Mg, and Se in Tibetan cataractous lenses and also in local samples of earth, drinking water, and staple foods were analyzed to estimate the possible relationship between environmental factors and primary cataract formation in Tibet. The Fe, Mg and Se contents in Tibetan cataracts were significantly lower in comparison with levels in those of Chengdu area, particularly the Se contents were low in both cataracts and local environment, suggesting a probable correlation between cataract formation and low Se contents in food and water.