The relationship between endemic fluorosis and the origin of fluoride in Chaoyang city

Objective To understand the relationship between endemic fluorosis and the origin of fluoride for supplying some strategic suggestion to control and prevent the endemic fluorosis in Chaoyang city, Guangdong province.Methods The fluoride contents in drinking water, irrigative water, rice, tea and soil were determined by fluoride ion selective electrode. Dental fluorosis conditions of 8~15 years old children were examined. Results Between fluorosis and non-fluorosis areas, the fluoride contents in rice and soil didn't show statistical difference (P0.05), but the fluoride contents in irrigative water did (P0.05). The fluoride contents in soil and rice has a positive correlation(r=0.525) as well as in those rice with the prevalence rate of dental fluorosis in the children aged 8～15( r=0.818). The fluoride content in tea was as high as 30.88mg/L. Contrarily, the relation of fluoride contents between irrigative water and soil, the relation of fluoride content in soil and dental fluorosis prevalence rate were less significant, those correlative coefficients were -0.237, -0.332 respectively. Conclusion The trend of dental fluorosis has been declined after safe water supply in Chaoyang. Rice, soil, irrigative water and tea were the other origin of the fluoride.