National annual monitoring report of drinking-water-borne endemic fluorosis in 2010 and 2011 / 中国地方病学杂志

ABSTRACT

Objective To grasp the operation quality of the water-improving projects for lowing fluoride level and to grasp the prevalence trend of fluorosis in drinking-water-borne fluorosis affected areas in China.Methods According to theSurveillance Scheme of Drinking-Water-Borne Endemic Fluorosis(Trial),314 counties were selected as monitoring counties in 2010 and 2011,respectively.Ten water-improving projects were randomly selected in each monitoring county every year.For each project,the operating condition was investigated and the fluoride level of tap water was determined.For each village,the fluoride level in drinking water was determined and the prevalence of dental fluorosis of all pupils aged 8-12 were surveyed.Dental fluorosis was diagnosed according to Dean method.Results ①A total of 1381 water-improving projects were monitored in 2010,among which normal operating projects accounted for 93.19％ (1287/1381) and those with qualified fluoride level accounted for 76.32％ (1054/1398).A total of 1408 water-improving projects were monitored in 2011.Normal operating projects accounted for 94.74％(1334/1408) and those with qualified fluoride level accounted for 79.26％ (1116/1408).②Total 319 villages with water-improving projects were monitored in 2010,and the number in 2011 was 327.The qualification rate of water fluoride content for 2010 and 2011 were 73.35％ (234/319) and 73.70％ (241/327),respectively.Total 84 villages without water-improving projects were monitored in 2010,and the number in 2011 was 88.Villages with fluoride level ＞ 1.2-2.0 mg/L,＞ 2.0-4.0 mg/L,and ＞ 4.0 mg/L in 2010 accounted for 47.62％ (40/84),42.86％ (36/84),and 9.52％ (8/84),respectively.The proportion in 2011 was 52.27％(46/88),38.64％(34/88),and 9.09％(8/88),respectively.③The detectable rates of dental fluorosis of children aged 8-12 in 2010 and 2011 were 26.97％(4347/16 119) and 24.98％(4027/16 123),respectively.In the monitored villages,the water-improving projects were under normal operation and fluoride content in water was qualified.And the rates for villages with water-improving projects under abnormal operation or fluoride content in water unqualified in 2010 and 2011 were 44.09％ (1721/3903) and 41.86％ (2188/5227),respectively.While the rates for villages without water-improving projects in 2010 and 2011 were 46.08％ (2802/6081) and 45.51％ (2804/6161),respectively.Conclusions The national normal operation rates of water-improving projects for lowing fluoride level are between 93％ and 95％.The qualification rate of fluoride content in drinking water is lower than 80％.The operation condition and water quality of the water-improving projects in China need to be improved.The prevalence of children dental fluorosis of affected villages has dropped significantly after low fluoride water is provided continuously.