Survey on water fluoride content and water-improving defluoridation projects in the endemic fluorosis areas of Gansu Province in 2005 / 中国地方病学杂志

ABSTRACT

Objective To investigate the distribution of water fluoride and the present status of water- improving delluoridation projects in the endemic fluorosis areas in Gansu Province. Methods According to "The National Technical Scheme for Endemic Disease Control in 2004" for the water improving projects, water fluoride content was determined from fluorosis villages in 34 counties of 11 cities in Gansu Province. The fluoride content in drinking water was assessed by F-ion selective electrode. Results Water fluoride content was determined in 1576 fluorosis villages of 34 counties. Water fluoride content of 7829 water samples was determined, and the fluoride content of 1891 samples was over standard. Water fluoride content was ≤ 1.00 mg/L(accounting for 75.19%) in 1185 villages and 1.00 mg/L(accounting for 24.81%) in 391 villages; the highest water fluoride content was 6.78 mg/L Nine hundred and ninety three water-improving and defluoridation projects were determined. Water fluoride content of 867 water-improving and defluoridation projects was determined; 768 projects had water fluoride content ≤1.00 mg/L(accounting for 87.67%) and water fluoride content of 108 projects was 1.00 mg/L(accounting for 12.33%),with the highest water fluoride content being 5.27 mg/L. Water-improving and delluoridation projects mostly relied on drilling a well to obtain under-grand water. Abandoned projects accounted for 30%. Conclusions In 34 counties of 11 cites(prefecture), nearly 30% of the villages had water fluoride content exceeding the standard. The situation of endemic fluorosis control is still serious in Gausu Province, countermeasures for endemic fluorosis must be carried out as soon as possible and surveillance of water-improving and defluoridation projects must be strengthened.