Influence of stove an d coal-burning mode on formation of severe endemic fluorosis regions in Guizhou Province / 中国地方病学杂志

ABSTRACT

Objective To explore the influence of stoves and mode of coal-burning on the prevalence of endemic fluorosis in Guizhou Province.Methods Three previous severe endemic villages and two mild villages(as control)were investigated by ways of random sampling in the present and retrospect epidemiological study on stove usage,coal burning mode and the severity of disease.Results Before the 1990's Of 20th century all the households in the previous severe endemic villages used the open stove without ventilated pipe(chimney)and dehydrated the corn over the coal-fire of the open stoves in house,which resulted in severe pollution of the corn and indoor air by fluoride.After the 1990's,each household,although still dried the corn with the coal fire,used the table stoves and iron stoves increasingly year by year,which resulted in the decrease of the emitted fluoride from the coal fire significantly,reduced the fluoride pollution of the indoor air and the main food,thus the incidence of endemic fluorosis consequently decreased. On the other hand, most of the households in the previous severe endemic villages such as Lianhe and Yuanzi still used the open, unventilated stove without chimney, very few installed chimney leading to outside of the room,the rates being 51.3%(41/80)and 41.7%(35/84),respectively.It was concordant to the high incidence of endemic fluorosis.Compared with 1979,the detective rates of dental fluorosis in the crowd aged above 8 years old were increased significantly in Hehua Village in 2006,90.51%(248/274)and 96.08%(392/408),respectively(χ2=7.85,P＜0.01).Conclusions The usage of stoves and mode of coal-burning significantly influence the incidence of the endemic fluorosis caused by domestic coal-burningin Guizhou Province,and inappropriated use of stove and the mode of coal burning are the key factors in cause the prevalence of the severe fluorosis in endemic regions in Guizhou.