An epidemiological investigation of endemic fluorosis in the alluvial plain area of the Yellow River, Shandong Province / 中华地方病学杂志

ABSTRACT

Objective To investigate the current prevalent status of endemic fluorosis in the alluvial plain area of the Yellow River in Shandong Province,in order to provide a scientific basis for developing control measures against the disease.Methods Six counties were selected as survey counties by random sampling,ten improvedwater projects were selected in each survey county,for the projects,the operating effect was investigated and water fluoride content was tested;three epidemic villages were chosen as survey villages in each county,the operating condition and the fluoride level of water were investigated in the villages with water improvement projects.Dental fluorosis of children aged 8 to 12 was surveyed,the urinary fluoride and skeletal fluorosis X-ray diagnosis were checked of adults over the age of 25.Water fluoride and urinary fluoride contents were detected via the F-ion selective electrode method,and the prevalence of dental fluorosis of all children aged 8 to 12 was diagnosed based on Clinical Diagnostic Criteria of Dental Fluorosis (WS/T 208-2011),skeletal fluorosis X-ray diagnosis was done based on the National Standard for Diagnosis of Endemic Skeletal Fluorosis (WS 192-2008).Results ①In the six counties,58 improved-water defluoridation projects were investigated,all projects were operated normally,the qualified rate of water fluoride content was 44.83％ (26/58).②A total of 19 villages that had water-improving and defluoridation projects were investigated,and all projects were operated normally,the qualified rate of water fluoride content was 42.11％ (8/19).③The overall rate of dental fluorosis among children aged 8 to 12 years old was 49.28％ (480/974),with the index of dental fluorosis as 1.01 in 19 villages,the prevalence of dental fluorosis was mild.In the qualified villages of water fluoride concentration,the positive rate of dental fluomsis among children aged 8 to 12 was 33.41％ (148/443),dental fluorosis index was 0.65,and the prevalence of dental fluorosis was extremely low;in the exceeding-standard villages of water fluoride content,the positive rate of dental fluorosis among children aged 8 to 12 was 62.52％ (332/531),dental fluorosis index was 1.36,and the prevalence of dental fluorosis was mild;the detection rate of dental fluorosis among children aged 8 to 12 of the villages with qualified fluoride content was lower than the rate of the villages with excessive fluoride (x2 =81.91,P ＜ 0.01).④X-ray detection rate of skeletal fluorosis in adults over the age of 25 was 6.14％ (53/863) in 17 villages,there was no statistically significant difference between the qualified villages and the exceeding-standard villages of water fluoride concentration (x2 =1.55,P ＞ 0.05),X-ray detection rate of skeletal fluorosis in adults was 5.04％ (20/397) and 7.08％ (33/466),respectively.In the qualified villages and the exceeding-standard villages of water fluoride,urinary fluoride geometric average and the exceeding rate of urinary fluoride were 1.50 mg/L,44.16％ (170/385) and 2.09 mg/L,62.58％ (286/466),respectively.In the qualified villages of water fluoride,the exceeding rate of adult urinary fluoride was lower than that in the exceeding-standard villages (x2 =28.58,P ＜ 0.01).Conclusions The prevention and control measures on endemic fluorosis have had some effects in the alluvial plain area of the Yellow River in Shandong Province.But the water fluoride content of water improving defluoridation projects still exceeds the national standard seriously,and endemic fluorosis has not been effectively controlled.Prevention measures should be further strengthened.