HEALTH-EFFECTS OF INDOOR FLUORIDE POLLUTION FROM COAL BURNING IN CHINA

The combustion of high fluoride-content coal as an energy resource for hearing, cooking, and food drying is a major exhaust emission source of suspended particulate matter and fluoride. High concentrations of t hese pollutants have been observed in indoor air of coal-burning famil ies in some rural areas in China. Because airborne fluoride has seriou s toxicological properties, fluoride pollution in indoor air and the p revalence of fluorosis have been analyzed in a fluorosis area and a he althy nonfluorosis area in China and in a rural area in Japan, For hum an health, fluoride in indoor air has nor only been directly inhaled b y residents but also has been absorbed in stored food such as corn, ch ilies, and potatoes. In the fluorosis area in China, concentrations of urinary fluoride in the residents have been much higher than in the n onfluorosis area in China and in the rural area in Japan. In the fluor osis area, almost all elementary and junior high school students 10-15 years of age had dental fluorosis. Osteosclerosis in the skeletal flu orosis patients was very serious. Urinary deoxypyridinoline in rural r esidents in China was much higher than in rural residents in Japan. Da ta suggest that bone resorption was extremely stimulated in the reside nts in China and that fluoride may stimulate both bone resorption and bone formation. Because indoor fluoride from combustion of coal is eas ily absorbed in stored food and because food consumption is a main sou rce of fluoride exposure, it is necessary ro reduce airborne fluoride and food contamination to prevent serious fluorosis in China.