An epidemiological study of drinking water type of endemic fluorosis in Shandong Province in 2013 / 中华地方病学杂志

ABSTRACT

Objective To study the prevalence of drinking water type of endemic fluorosis in Shandong Province,and to provide a scientific basis in making strategies for prevention and control of the disease.Methods Ten counties (cities,districts) were selected by random number table method to carry out the epidemiological study,and to study the progress and effect of water-improving and defluoridation projects.Three villages in each county (city,district) were chosen to determine fluoride content of drinking water and to check the prevalence of dental fluorosis of children 8 to 12 years old.Water fluoride content was determined with fluoride ion-selective electrode,and dental fluorosis was diagnosed by the Deans method.Results In the 10 counties (cities,districts),a total of 515 water-improving and defluoridation projects were built covering 3 207 fluorosis villages,and the waterimproving rate was 81.71％ (3 207/3 925).A total of 85 water-improving and defluoridation projects were investigated in the 10 counties (cities,districts),and all of the projects were operating normally.The number of projects that water fluoride concentration ≤ 1.20 mg/L was 51; the qualified rate of water fluoride concentration was 60.00％ (51/85),and the maximum value of water fluoride was 4.38 mg/L.A total of 29 villages that had waterimproving and defluoridation projects were investigated in the 10 counties (cities,districts),and the number of villages that mean of water fluoride ≤ 1.20 mg/L was 21,accounting for 72.41％ (21/29); ＞ 1.20 mg/L was 8,accounting for 27.59％ (8/29),and the maximum value of water fluoride was 4.02 mg/L.In the 21 qualified villages of water fluoride concentration,a total of 1 023 children aged 8 to 12 were examined; the positive rate of dental fluorosis was 38.12％ (390/1 023); dental fluorosis index was 0.67,and the prevalence of dental fluorosis was extremely low.In the 8 exceeding-standard villages of water fluoride content,a total of 449 children aged 8 to 12 were examined; the positive rate of dental fluorosis was 54.79％ (246/449); dental fluorosis index was 1.18,and the prevalence of dental fluorosis was mild.Conclusion In Shandong Province,the water fluoride content of waterimproving and defluoridation projects exceeds the national standard seriously,and the condition of children's dental fluorosis is still serious,and the measures of water-defluoridation should be further strengthened.