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Objective To investigate the effects of administrative region changes on prevention and control of fluorosis,in order to provide a scientific basis for evaluation and improvement of prevention and control measures.Methods An investigation was conducted in all drinking water-born endemic fluorosis areas in Hangzhou in 2017,to evaluate the status quo of water-improving defluoridation projects,measure the water fluoride content with "the Standard Detection Methods for Domestic Drinking Water" (GB/T 5750.7-2006),detect the dental fluorosis with Dean method and the urinary fluoride content by fluoride selective electrode method in children aged 8 to 12 years old.Results The historical endemic fluorosis areas in Hangzhou now involved 38 natural villages of 22 administrativevillages in 8 townships of 5 counties (cities and districts).All villages had completed water-improving projects which were running well as the fluoride contents of drinking water were less than 1.00 mg/L.The detection rate of dental fluorosis was 1.13％ (9/795) among children aged 8-12 years.A total of 198 urine samples were tested,the urinary fluoride content varied from 0.12 to 2.90 mg/L,and the geometric mean was 0.77 mg/L.Conclusion Administrative region changes do not influence the effect of water-improving defluoridation projects,but management and monitoring of the water-improving projects still should be strengthened.
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Objective To understand the drinking water type fluorosis in Jiangsu Province, dynamically monitor the disease trends, and to evaluate the operation effect of the water project comprehensively. Methods Twenty-six fluorosis districts and counties in Xuzhou, Lianyungang, Suqian, Huaian and Yancheng were selected as the monitoring sites. The change of water improvement engineering and the value of water fluoride were surveyed and tested. There were three different situations of changed water: the water improvement engineering operated normally was the first, the water improvement engineering operated abnormally or water fluorine excesses the standard was the second,and without water improvement was the last.The teeth of children aged 8 to 12 years were checked according to the method of Dean. The skeletal fluorosis of adults was checked according to "Diagnostic Criteria of Endemic Skeletal Fluorosis"(WS 192-2008) by X-ray inspection. Results The normal operation rates of changed water project from 2011 to 2015 were 100.00% (30/30), 85.29% (29/34), 82.50% (33/40), 95.92% (47/49),and 97.83%(45/46),and the excessive rates of water fluorosis for normal operating engineering were 13.33%(4/30),17.24%(5/29),9.09%(3/33),14.89%(7/47),and 11.11%(5/45).The dental fluorosis detection rates of children aged 8 to 12 years were 33.68% (194/576), 28.30% (711/2 512), 36.25% (1 577/4 350), 22.06% (837/3 794), and 20.44% (903/4 417) from 2011 to 2015, the differences were statistically significant (χ2= 190.952, P < 0.05). The dental fluorosis detection rates in the three situations of water changed annually was statistically significant (χ2=129.336, 130.402, 21.419, P < 0.05). The detection rates between three different water conditions were 21.88% (2 857/13 057), 57.23% (1 156/2 020), 36.54%(209/572), and the differences were statistically significant (χ2=206.295, P < 0.05). Differences between the villages with water improvement engineering changed but not worked and the villages with water improvement engineering changed and worked well and the villages without the water improvement engineering were statistically significant(χ2=200.861,36.336,P<0.0125).The difference of detection rates between the villages with normal operation and the villages without water improvement was not statistically significant(χ2=2.131, P>0.0125).The X-ray detection rates of skeletal fluorosis in adults from 2011-2015 were 17.83% (51/286), 16.61% (49/295), 15.36% (51/332), 10.95% (53/484), and 5.16% (16/310); urinary fluoride range was 0.02 - 22.0 mg/L; the geometric average was 0.67 - 4.06 mg/L, there was no statistical significant difference of skeletal fluorosis distribution annually(χ2=6.060, P > 0.05). Conclusion The general condition of drinking water type fluorosis in Jiangsu Province from 2011 to 2015 is gradually under control, but the engineering operation and water quality improvement still need to be improved; water change project not functioning or with excess fluorine is more harmful to children's teeth.
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Objective Through the dynamical monitoring of the water improvement projects operation,we intend to understand the prevalent trends of endemic fluorosis of children aged 8 to 12 in Hubei,to evaluate the effect of control measures and to provide the basis for making preventive measures.Methods In Hubei,ten surveillance counties were selected,and three epidemic villages were selected as fixed monitoring villages in each county from 2010 to 2014.In those villages,the operation situation of water improvement projects and the fluoride content in drinking water were detected,and the dental fluorosis of children aged 8 to 12 was diagnosed.Results From 2010 to 2014,the normal operation rate of water improvement projects was 75.61％-100.00％,the average of water fluorine content did not change,the differences were not statistically significant (F =2.00,P ＞ 0.05).The numbers of water improvement projects with water fluorine content in excessive amount was increased in the past five years which was only one project in 2010-2012 and was increased to two projects in 2013 and 2014.In 2010-2014,the dental fluorosis prevalence rate of whole children was 9.45％ (525/5 557),the dental fluorosis prevalence rate of exceeding-standard villages of water fluoride content was 42.40％ (92/217),the dental fluorosis prevalence rate of qualified villages was 8.11％ (433/5 340).The children's dental fluorosis prevalence rate of exceeding-standard villages of water fluoride content was higher than that in qualified villages;the differences were statistically significant (x2 =282.60,P ＜ 0.05).Conclusions The operation rate of water-improving projects is mostly higher than 90％,and so is the qualification rate of fluoride content in drinking water.The operation condition and water quality of the water-improving projects in Hubei need to be improved.The prevalence of children dental fluorosis of affected villages has dropped significantly after low fluoride water is provided continuously.
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Objective To understand the schedule and effectiveness of water-improving defluoridation projects comprehensively in control of fluorosis in drinking-water-borne endemic fluorosis areas in Shaanxi Province,and to provide a scientific basis for making strategies in prevention and control the disease for the next step.Methods The progress of drinking-water-borne endemic fluorosis water-improving defluoridation projects and operation condition were investigated in Shaanxi (fluoride content of drinking water was greater than 1.2 mg/L in the endemic areas) in 2014,and children aged 8 to 12 in 32 epidemic villages of six counties including Jingbian,Dingbian,Dali,Jingyang,Qian and Liquan were selected to survey dental fluorosis.Results In Shaanxi Province,the number of villages with water fluorine content of more than 1.2 mg/L was 5 005 and water improvement rate was 83.42％ (4 175/5 005),water-improving projects operated normally rate was 85.05％ (3 551/4 175),and scraped was 37,accounted for 0.89％ (37/4 175).There were 830 epidemic villages without water-improving projects in Shaanxi Province,and high fluoride exposed population was 579 400,mainly distributed in Yulin,Xianyang,Weinan and Yan'an cities.A total of 1 849 children aged 8 to 12 in the 6 counties were examined,the detection rate of dental fluorosis was 56.57％ (1 046/1 849),the index of dental fluorosis was 1.11.Conclusion In drinking-water-borne fluorosis epidemic areas of Shaanxi,the improved-water rate is generally high,and the normal operation of waterimproving projects is overall good,but the measures for water-improving defluoridation must be reinforced and improved.
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Objective To investigate the prevalence of children dental fluorosis in drinking-water-borne endemic fluorosis areas in Liaoning province and to evaluate the disease prevention effects of water improvement measures.Methods Haicheng city,Linghai city,Faku county,Fumeng county,Liaoyang county and Jianping county six endemic fluorosis diseased counties (cities) of Liaoning province were included in the study in September 2011.In each county,3 water improvement villages were selected as survey points.In each surveyed village,children aged 8-12 were generally surveyed the prevalence of dental fluorosis.One tap water sample was collected in each surveyed village for determination of water fluorine.level.Results A total of 786 children aged 8-12 were examined; 110 of them were found with dental fluorosis; detection rate of dental fluorosis was 14.0％ ; no defect case of dental fluorosis was found,and dental fluorosis index was 0.27.Among the cases,very mild were 76 cases,and the detection rate was 9.7％; mild 33 cases,the detection rate was 4.2％; moderate 1 case,the detection rate was 0.1％; and no severe case.Four cases were in the eight-year-old group,accounting for 3.6％ of the total number of cases; 20 in the 9-year-old group,accounting for 18.2％ ; 26 in the 10-year-old group,accounting for 23.6％; 32 in the 11-year-old group,accounting for 29.1％; and 28 in the 12-year-old group,accounting for 25.5％.The differences of detection rates of dental fluorosis of children in each age groups were statistically significant (x2 =13.57,P ＜ 0.05).Water fluoride of the 18 water samples ranged from 0.34 to 2.03 mg/L; 77.8％ (14/18) of the water improvement areas reached the control standard for endemic fluorosis areas.Conclusion The prevalence of dental fluorosis in the areas with high fluoride in drinking water remains high,the measures of water improvement should be strengthened.
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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.