SKELETAL FLUOROSIS FROM INDOOR BURNING OF COAL IN SOUTHWESTERN CHINA

Abstract

SUMMARY: The effects of airborne fluoride from unvented indoor burning of fluoride-rich coal on the bones and teeth of residents of two rural villages in SW China were investigated and compared. In the highly polluted village of Xaochang in Sichuan Province, stage III skeletal fluorosis was found in 43 (84%) of 51 examinees. In the moderately polluted village of Minzhu in Guizhu Province, this stage was seen in 25 (51%) of 49 examinees. In the nonpolluted control village of Shucai in Jiangxi Province in SE China, none of 47 exami- nees showed any evidence of skeletal fluorosis. In Minzhu, but not in Xao- chang, significantly more males than females were afflicted with stage III skeletal fluorosis. In contrast with Xaochang, some examinees in Minzhu had serious skeletal effects but normal teeth or minor dental fluorosis. A high fre- quency of extremital transverse bone growth lines was observed in Xaochang but not in Minzhu. These findings suggest that greater exposure to fluoride occurred during infancy and early childhood in Xaochang than in Minzhu.