Endemic fluorosis in Huangyuan county Qinghai province in 2009: an analysis of surveillance results

Abstract

Objective To investigate the prevalence change of drinking water type of endemic fluorosis and the effect of control measures implemented in Huangyuan county of Qinghai province. Methods In 2009, all the endemic fluorosis villages in Huangyuan county were divided into two degrees, light and medium, according to the water fluorosis content before implementing the improving water project, 1 to 2 villages were selected from each degree village, respectively,as monitoring sites, and a total of 3 villages were selected. Source water and tap water samples were collected from each village and water fluoride concentration was determined. Dental fluorosis of all children aged 8 to 12 of monitoring villages was examined, and urine samples were collected by age group of children for determination of urinary fluoride. Clinical skeletal fluorosis of adults over 16 years of age was examined, and 20 copies of adults urine samples were collected to determine urinary fluoride. One village was selected in the 3 villages monitored to conduct X-rays examination of skeletal fluorosis. Water fluoride was tested in accordance with the "Non-metallic Targets Test Methods for Drinking Water" (GB/T 5750.6-2006); urinary fluoride was tested by fluoride ion-selective electrode method (WS/T 89-1996); dental fluorosis was diagnosed using Dean method;adult skeletal fluorosis was diagnosed by "Clinical Diagnostic Criteria for Endemic Skeletal Fluorosis"(WS 192-2008). Results Twelve water samples were assayed, water fluoride was (0.35 ± 0.43) mg/L. The detectable rate of dental fluorosis of 122 children aged 8-12 was 34.43%(42/122) and the geometric mean urinary fluoride was 0.89 mg/L of the 96 children. Of the 834 adults aged 16 and over, clinical detection of skeletal fluorosis was 47.72% (398/836) and geometric mean urinary fluoride was 1.10 mg/L of the 65 cases of adult urine samples assayed, detection rate of X-rays was 31.4% (11/35) in Gangou village of the 35 adults examined.Conclusions In Huangyuan county, water fluoride of the 3 surveyed villages are normal but the endemic fluorosis is still serious. It should strengthen monitoring and analyze the causes and improve prevention measures. Key words: Fluorosis;  Drinking;  Data collection;  Osteofluorosis