贵州省燃煤污染型氟中毒重点病区主要氟污染来源

目的 了解贵州省燃煤污染型地方性氟中毒病区主要氟污染来源.方法 根据2000年贵州省地方性氟中毒流行病学调查结果,于2007年采用分层随机抽样方法,在氟斑牙流行强度为较显著(A类)和中等(B类)的病区各抽取4个县,每个县抽取3个乡,每个乡抽取3个村,每个村抽取30户,入户调查煤和拌煤黏土的使用量及比例,同时采集主要生活饮水、煤、拌煤黏土样品进行含氟量测定.结果 8个病区县生活饮用水含氟量在0.01～0.50 mg/L,平均0.13 mg/L,远低于国家生活饮用水卫生标准(GB 5749-2006).煤氟中位数为132.97 mg/kg,最低为23.62 mg/kg,最高达4269.19 mg/kg;黏土氟中位数为853.42 mg/kg,最低为53.93mg/kg,最高达4268.38 mg/kg;黏土氟是煤氟的6.4倍.煤对室内空气氟污染的贡献率平均为49.27%,其中有5个县的贡献率在50.00%以上,但有2个县拌煤黏土对室内空气氟污染的贡献率达到60.00%以上.结论 煤及拌煤黏土都是贵州省地方性氟中毒病区主要氟污染来源;在现阶段的防治工作中,必须坚持采取以改良炉灶为主的综合防治措施.

Main fluoride origin of the key regions of coal-burning endemic fluorosis in Guizhou Province

Objective To explore the source of fluoride in the key endemic regions of fluorosis induced by coal-burning pollution in Guizhou Province. Methods Based on the results of the investigation in the whole province in 2000, stratified and random sampling methods were adopted. Four counties in the A type endemic regions where the incidence of dental fluorosis was very high and 4 counties in the B type endemic regions where the incidence was moderate were chosen, and 3 towns of each county and 3 villages of each town were randomly taken as investigation fields in 2007. Thirty households of each village were investigated, and the contents of fuoride in the samples of drinking water, coal and clay were determined. Results The concentration of fluoride in the drinking water in endemic counties was 0.01-0.50 mg/L(average 0.13 mg/L), far lower than the National Standard(GB 5749-2006). The median content of fluoride in the coal was 132.97 mg/kg, the lowest was 23.62 mg/kg and the highest 4269.19 mg/kg. The median content of fluoride in the clay was 853.42 mg/kg, the lowest was 53.93 mg/kg and the highest 4268.38 mg/kg. The median content of fluoride in the clay was 6.4 times that of the coal. The contribution rate of the coal to the pollution of indoor air in the endemic counties investegated was 49.27% and it was above 50.00% in 5 counties. The rate of the clay was above 60.00% in 2 counties. Conclusions Both the coal and the clay are the sources of fluoride pollution in the endemic regions of Guizhou Province. It is strengthened that comprehensive countermeasures of installing and improving cooking stoves should be taken to control endemic fluorosis.