ABSTRACT
Objective To investigate the prevalence of children dental fluorosis in drinking-water-borne endemic fluorosis areas in Liaoning province and to evaluate the disease prevention effects of water improvement measures.Methods Haicheng city,Linghai city,Faku county,Fumeng county,Liaoyang county and Jianping county six endemic fluorosis diseased counties (cities) of Liaoning province were included in the study in September 2011.In each county,3 water improvement villages were selected as survey points.In each surveyed village,children aged 8-12 were generally surveyed the prevalence of dental fluorosis.One tap water sample was collected in each surveyed village for determination of water fluorine.level.Results A total of 786 children aged 8-12 were examined; 110 of them were found with dental fluorosis; detection rate of dental fluorosis was 14.0％ ; no defect case of dental fluorosis was found,and dental fluorosis index was 0.27.Among the cases,very mild were 76 cases,and the detection rate was 9.7％; mild 33 cases,the detection rate was 4.2％; moderate 1 case,the detection rate was 0.1％; and no severe case.Four cases were in the eight-year-old group,accounting for 3.6％ of the total number of cases; 20 in the 9-year-old group,accounting for 18.2％ ; 26 in the 10-year-old group,accounting for 23.6％; 32 in the 11-year-old group,accounting for 29.1％; and 28 in the 12-year-old group,accounting for 25.5％.The differences of detection rates of dental fluorosis of children in each age groups were statistically significant (x2 =13.57,P ＜ 0.05).Water fluoride of the 18 water samples ranged from 0.34 to 2.03 mg/L; 77.8％ (14/18) of the water improvement areas reached the control standard for endemic fluorosis areas.Conclusion The prevalence of dental fluorosis in the areas with high fluoride in drinking water remains high,the measures of water improvement should be strengthened.
ABSTRACT
Objective To establish information management systems of drinking water defluoridation project in water-related endemic fluorosis areas and investigate the status of drinking water defluoridation project in Liaoning, provide the basis for the development of control measures. Methods Global positioning systems (GPS)and geographic information systems(GIS) were used in the study in August 2006 - July 2008. Water defluoridation projects of 1234 in 48 counties(cities, districts) in drinking water type of fluorosis areas were positioned. Latitude and longitude, water samples, water fluoride content were collected or tested. GIS was used to establish information management system of water defluoridation projects. Results We have established information management system for the facilities of decreasing water fluorine in drinking water type of endemic fluorosis regions in Liaoning. One thousand two hundred and thirty four defluoridation facilities distributed in east longitude between 39.39° - 43.37°,north latitude between 119.25° - 125.50°, and altitude between - 6.60 and 801.14 meter in 48 endemic fluorosis counties in 13 cities. Nine hundred and twenty seven facilities for decreasing fluorine were able to supply water regularly, accounting for 75.1% of investigated projects;29 facilities was .not yet completely rebuilt, accounting for 2.4%;278 facilities(supply water for 344 villages) were out of order or discarded for 22.5% of investigated projects.Water fluorine contents of 63 facilities were greater than 1.2 mg/L, accounting for 6.8% of investigation project.Facilities working regularly and water fluorine was in accord with hygienic standard for drinking water facilities were 70.0%. Conclusions The establishment of Liaoning province defluoridation project information management system in the whole province of drinking water type of fluorosis areas provides scientific basis for accurate decision-making on prevention and control of the disease.