ABSTRACT
Objective To understand the prevailing status of coal-burning endemic fluorosis in Henan, and to provide scientific grounds for endemic fluorosis prevention. Methods Undertook general surveillance on factors such as coal using, living habit, main foods, the structure of the houses and the fluoride content in drinking-water among 1832 historical coal-burning endemic fluorosis villages within 13 counties in 2006 and 2007, and conducted focal point sampling survey on 216 villages which still using local high-fluoride. For all children aged 8-12 years of each village, conducted dental fluorosis examination and collected 30 immediate urinary samples for fluoride content determination. Results The fluoride content in drinking-water of all historical fluorosis villages was below 1.0 mg/L. Households having individual kitchens accounted for 93.7%(241 281/257 393), those with stoves having smoke evacuation devices accounted for 41.9% (107 917/257 393), those using local high-fluoride coal for cooking accounted for 28.6%(73 686/257 393), those using local high-fluoride coal for heating accounted for 24.1%(61 924/257 393). Villages with serf-supply of main foods accounted for 95.7%(1753/1832) of all fluorosis villages. Solar drying food was used in all households. Villages with dental fluorosis detection rate for children aged 8 to 12 years above 30.0% accounted for 16.2%(35/216), which axe all in Luoyang City. Among 77.8%(168/216) of fluorosis villages, children' s urinary fluoride concentrations were no higher than 1.50 mg/L. Conclusions Coal-burning endemic fluorosis areas in Henan Province were decreased greatly and the extent of the health hazard was becoming slightly. The detection rate of dental fluorosis for children aged 8 to 12 years of 8 counties had reached the standard for fluorosis control, whereas the other 5 counties had not yet, all located in Luoyang City.