Epidemiological investigation of endemic fluorosis along the Yellow River basin of Shandong Province

Objective To investigate the current prevailing status of endemic fluorosis in the Yellow River basin of Shandong Province and to provide the scientific evidence for making strategies in prevention and control.Methods Nine counties were chosen to carry out the epidemiological investigation.The content of fluoride in drinking water was determined by F-ion selective electrode and dental fluorosis of children aged 8～12 years old was diagnosed by Deans method.Results Water fluoride content was determined in 1761 fluorosis villages,among which 606 villages had water fluoride content≤1.00 mg/L,accounting for 34.41%(606/1761);1155 villages had water fluoride content＞1.00 mg/L,which accounted for 65.59%(1155/1761).The highest water fluoride content was 11.33 mg/L.Water fluoride content of 618 water-improving and defluoridation projects had been determined,among which 449 projects had water fluoride content≤1.00 mg/L and accounted for 72.65%(449/618),169 projects had water fluoride content＞1.00 mg/L and accounted for 27.35%(169/618),the highest water fluoride content was 5.85 mg/L.The total rate of dental fluorosis of children aged 8～12 years old was 45.03%(25 579/56 804) and the index of dental fluorosis was 0.80. Conclusions In the Yellow River basin in Shandong Province,up to 50.00%in the villages the water fluoride content exceeds the county standard(≤1.00 mg/L).The prevalence of endemic fluorosis in the basin hasn't been effectively controlled.So the counterrneasures for endemic fluorosis should be carried out as soon as possible. Key words: Endemic diseases; Fluoride poisoning; Drinking water; Epidemiology