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.
ABSTRACT
ObjectiveTo investigate the development trend of drinking water type of endemic fluorosis in Qinghai province, and to provide the basis for the prevention and treatment of the disease. MethodsIn 2009, six monitoring counties were chosen by using simple random sampling methods, all diseased villages of the six monitoring counties were classified into light, moderate and severe disease types according to water fluorine content on the historical data, and 1 village was respectively chosen from each type. In monitoring villages with improved water, 3 tap water and one source water samples were collected, respectively. Five water samples were collected randomly in water unimproved monitoring villages according to water well locations of east, west, south, north and center. The fluorine content in water and urine was determined according to the Standard Testing Methods for Drinking Water (GB/T 5750-2006). Children aged 8 to 12 were examined for dental fluorosis by Dean method.Clinical osteofluorosis of all the resident over the age of 16 was examined, 2 village of these counties were randomly selected, and clinically diagnosed patients with skeletal fluorosis were examined again by X-ray using Diagnostic Criteria of Endemic Skeletal Fluorosis (WS 192-2008). Urine sample of 30 children aged 8 to 12 and of 20 adults over the age of 16 were randomly collected and urinary fluoride was determined by F-ion selective electrode method (WS/T 89-2006). ResultsImproving water projects had been implemented in 14 monitoring villages of the 18 villages in 6 counties, the rate of improved-water was 77.78％(14/18). Among the 14 projects, 5 improved-water projects ran normally, and 9 projects ran with intermittently water supply. Seventy-five water samples were tested, themean of water fluoride was 0.48 mg/L. The prevalence of dental fluorosis was 31.95％ (285/892), that of clinical skeletal fluorosis was 36.55％(1570/4295) and the X-ray detection rate of skeletal fluorosis was 25.64％ (20/78).Five hundred and seventy-one urine samples of children were determined, and geometric mean of urinary fluorine was 1.04 mg/L; 370 adult urine samples were determined, and geometric mean of urinary fluorine was 1.52 mg/L Conclusion Epidemic of drinking water type of endemic fluorosis is still serious in Qinghai province, and drinking water defluoride measures should be further strengthened and improved.