Selenium in geo-ecosystem and its relation to endemic diseases in China

Abstract

In China, Se deficiency is associated with Keshan disease and Kaschin-Beck disease. This paper further demonstrates this relationship by studying the Se levels in the geo-ecosystem substances, including soil, plant, herbage, food grain, wool and human hair in disease affected areas and in control non-disease areas. Buteha Qi and Tailai counties in Northeast China were selected as the typical areas for these studies. The results show that in affected areas the average Se contents were: for soil, 0.125mg kg1, plants, 0.057 mg kg−1; herbage, 0.026 mg kg1; wheat, 0.012 mg kg−1; maize, 0.008 mg kg1; wool, 0.046 mg kg−; and human hair, 0.144 mg kg1. In the control area, the substances mentioned above all had higher Se contents compared with those in the affected area. Thus, it was shown that the geo-ecosystem of the affected area was low in Se, an important reason for the occurrence of Keshan disease and Kaschin-Beck disease. In recent years, some increase in the Se level of human hair was also found in the studied areas. This increase coincides with the decline, since the mid 1980's, of the incidence of the two diseases. An elevation in hair Se may, therefore, be a good indication of an improved Se intake of the subject population.