Outcome analysis on endemic fluorosis control in Gansu Province in 2006

Abstract

Objective To investigate the distribution of water fluoride and the present status of water-improving defuoridation projects in the endmie fluorosis areas in Gansu Province in 2006. Methods The content of fluoride in drinking water in 18 endemic disease counties was screened, and the defluoridation projects built after the 1980s were supervised and inspected. The content of fluoride in drinking water was assessed by F-ion selective electrode. Results Fluoride content was determined in water of 6260 sources in 1252 fluorosis villages in 18 counties, with 63.50% (3975/6260)≤1.0 mg/L and 36.50%(2285/6260)>1.0 mg/L. Nine hundred and ninty-seven water-improving and clefluoridation projects had been investigated in 16 counties, among which 95.49% (952/997) were function well, and projects intermittently running or abandoned respectively accounted for 3.11% (31/997) and 1.40%(14/997). Nine hundred and eighty-three sources of water treated by the water-improving and defluoridation projects had been determined for fluoride content, it turned out that 91.76% (902/983) were within the standard, only 8.24% (81/983) were not; as for outlet and leftover water of 934 water-improving and defluoridatian projects determined for water fluoride content, qualified projects accounted for 92.08% (860/934) and 91.97%(859/934), leaving 7.92%(74/934) and 8.03%(75/934) disqualified, respectively. Water-improving and defluoridation projects mostly relied on drilling a well in gaining under-ground water or collecting surface-ground water, so under-ground water and surface-ground water are the majority. Conclusions Water fluoride content exceeds the standard in some of the villages. A few projects do not function well. Fluorosis damage still exists in Gansu Province, therefore countermeasures for endemic fluorosis must be carried out as promptly as possible and surveillance on water-improving and defluoridation projects must be strengthened and managed. Key words: Fluoride poisoning; Drinking; Data collection