An investigation of children's dental fluorosis and intelligence in drinking water-type of endemic fluorosis area in Xi'an / 中华地方病学杂志

ABSTRACT

Objective To investigate the dental fluorosis and intelligence level of children in drinking water-type of endemic fluorosis areas in Xi'an,and to provide a scientific basis for development of prevention and control strategies.Methods In 2016,six drinking water-type of endemic fluorosis villages and one non-diseased village were selected as investigation sites in Xi'an.According to the detection rate and prevalence of dental fluorosis in children,six diseased villages were divided into three groups,the disease light-affected areas were Huidong and Xingnan,the moderate-affected areas were Liulin and Xiazhu,and the serious-affected areas were Hetou and Xiaoyang;and the Deng village was the non-diseased.A cross-sectional survey was conducted to collect 3 tap water samples in each village to test the fluorine content in water.For all children aged 8 to 12 years in diseased villages and 100 children aged 8 to 12 years in non-diseased villages,dental fluorosis examination and intelligence test were carried out.Results Mean value of water fluoride in non-diseased village and endemic fluorosis areas were (0.25 ± 0.01),(0.78 ± 0.43) mg/L,and the water fluoride content in two diseased villages was over 1.20 mg/L.The detection rate of dental fluorosis in children aged 8 to 12 (30.32％,67/221) in diseased areas was significantly higher than that in non-diseased area (2.00％,2/100;x2 =31.32,P ＜ 0.01).Children's IQ scores in the four groups were 108.68 ± 10.83,102.54 ± 12.54,101.70 ± 14.85,93.45 ± 10.84,and the IQ scores were decreased with the severity of dental fluorosis,the difference in IQ scores was significant between the endemic fluorosis areas and non-endemic fluorosis area (P ＜ 0.05);the percentage of children with IQ≤89 in endemic fluorosis areas was significantly higher than that in non-endemic fluorosis area (x2 =22.02,P ＜ 0.01).The IQ scores of children with dental fluorosis was 94.96 ± 13.75,and the IQ was 105.26 ± 10.19 in children with normal condition,the difference was significant (t =5.61,P ＜ 0.01),the mean value of IQ was decreased with the severity of dental fluorosis (F =7.42,P ＜ 0.05),the percentage of children with IQ≤89 in patient was higher than that in normal children,the difference was significant (x2 =45.70,P ＜ 0.01).Conclusion Low level of water fluoride still has negative influence on children's dental health and intelligence,water improving and surveillance should be strengthened to ensure the health of children.