Epidemiological investigation and analysis of water-related endemic fluorosis in the south area of Shandong province in 2009

Abstract

Objective To investigate prevailing status of endemic fluorosis in south area of Shandong province and to provide a scientific basis for formulating control measures against disease.Methods According to present distribution of fluorosis areas in south area of Shandong province and the Shandong Province Technical Scheme for Endemic Disease Control,13 counties(districts) in south area of Shandong province were selected as survey counties in 2009.Based on state of endemic fluorosis,the disease was classified into light,moderate and severe types in 13 monitoring counties (districts),and one diseased village was selected from each type as survey spots.The drinking water fluoride level,the prevalence of dental fluorosis of children aged 8-12,adult clinical skeletal fluorosis and urinary fluoride level of children and adults were surveyed in 39 villages selected.The content of fluoride in drinking water and urine was dctermined by F-ion selective electrode while dental fluorosis of children aged 8-12 was diagnosed by Dean method and adults skeletal fluorosis by national standard for Diagnosis of Endemic Skeletal Fluorosis (WS 192-2008).Results A total of 172 water samples were tested in 39 villages(26 villages with improved water and 13 villages with unimproved water) of 13 counties(districts),the fluoride content of 74 water samples(51 from 13 villages with unimproved water and 23 from 6 villages with improved water) exceeded national standard(＞ 1.0 mg/L),and rate of exceeded standard was 43.02％(74/172) with 24 of ＞ 2.0-4.0 mg/L and 3 of ＞ 4.0 mg/L,and maximum value of water fluoride was 7.76 mg/L.A total of 1118 copies of children urine samples were tested,geometric mean of urinary fluoride was 1.82 mg/L; 764 copies of adults' urine samples were tested,geometric mean of urinary fluoride was 1.98 mg/L.A total of 1908 children aged 8-12 were examined of dental fluorosis,the detection rate was 45.18％ (862/1908),tooth defection rate was 9.12％ (174/1908),and dental fluorosis index was 1.07.A total of 25 295 adults were checked of clinical skeletal fluorosis,the detection rate was 5.96％(1509/25 296) with 670 moderate or scrious cases.Conclusions In south area of Shandong province,excessive water fluoride is still serious,mainly in diseased villages with unimproved water(including water improvement villages discarded water improvement thereafter).Urine fluoride remains at a relatively high level,and dental and skeletal fluorosis are still comparatively serious.High tluoride hazard still exists to a certain degree.Therefore,the scientific control measures need to be strengthened to control prevalent of endemic fluorosis. Key words: Fluorine; Fluorosis, dental; Osteofluorosis; Data collection