Hydrochemical anomaly of drinking waters in some endemic Kashin-Beck disease areas of Tibet,China

Kashin-Beck disease (KBD) has been identified in some areas of Tibet, China. In this work, the Sangri, Nimu, Xietongmen and Gongbujiangda counties of Tibet were selected as case study areas to understand the relationship between KBD occurrence and chemical composition of drinking water. 30 drinking water samples were collected in the KBD-affected and KBD-unaffected villages of these four counties, and the hydrochemistry of endemic and non-endemic samples was compared. The results show that HCO₃–Ca, HCO₃–Ca·Na, and HCO₃·SO₄–Ca are the major hydrochemical types of water samples from both KBD-affected and KBD-unaffected villages. Although Se deficiency in environment has been widely regarded as an important cause of KBD, the Se concentrations in the drinking water samples do not correlate with KBD occurrence in the study areas. However, there are significant differences between the concentrations of Al, Fe, Na, Mn, Cd, Co, Cu, Ba and Mo in the endemic drinking water samples and those in the non-endemic samples, indicating that these constituents may be related to the prevalence of KBD in the study areas.