云南昭通氟中毒区煤、烘烤粮食、黏土和饮用水中砷、硒、汞的含量

为探讨昭通氟中毒地区煤和粮食中砷、硒、汞的含量和分布，在昭通镇雄和威信地区系统采集了160个煤、粮食、饮用水等样品，用AFS-820双道原子荧光光度计对样品中的砷、硒、汞含量进行了测定.中毒区晚二叠世龙潭组主采煤层砷含量为8.84 mg/kg.在居民中发现砷含量 89.09 mg/kg的高砷煤.煤中的硒、汞含量较低; 煤层中黄铁矿结核中的硒、汞含量高.中毒区烘烤后的玉米和辣椒全部含有超过国家规定的食品中砷限量卫生标准（0.7 mg/kg）的砷.烘烤后的辣椒中全部含有超过国家规定的食品中硒、汞限量标准，但烘烤后的玉米大多数没有超标；昭通氟中毒区的拌煤黏土大多是高砷土，平均砷含量大于16 mg/kg, 但黏土中硒、汞含量较低.病区饮用水中的砷含量一般低于国家饮用水砷中毒标准,饮用水中硒、汞均低.云南昭通氟中毒区有高砷煤存在,黄铁矿结核和部分亮煤的砷含量高.云南昭通氟中毒地区存在着高砷介质--烘烤后的高砷玉米和辣椒，氟中毒区烘烤粮食中的砷可能来源于煤和拌煤黏土中的砷.

Content of arsenic, selenium, mercury in the coal, food, clay and drinking water in the Zhaotong fluorosis area, eastern Yunnan Province

About 160 samples of coal,corn,capsicum and drinking water were collected from endemic fluorosis area of Zhenxiong and Weixin County,Zhaotong City of Yunnan Province,to determine the arsenic(As),seleni- um(Se),and mercury(Hg)content by AAF-800.The study found that the As content in the main coal seam from the Late Permian coal mines in Zhaotong City is 8.84 mg/kg,and some civil coal can reach 89.09 mg/kg. The Se and Hg in the coal samples of Late Permian is lower,but Se and Hg are more concentrated in the pyritic coal balls and the pyritic gangue of the coal seam.The As content in coal-burning dried corn and capsicum contain more than 0.7 mg/kg the natural standard amount of arsenic content allowed in food by China.The Se and Hg con- tent in the coal-burning dried corn is lower than the natural standard of Se and Hg content in the food of China,but Se and Hg content of coal-burning dried capsicum is exceed the amount allowed by the natural standard in food of China.Clay was used as an additive for the coal-burning process and as a binder in making briquettes,contain a high content of As,generally more than 16 mg/kg.However,the Se and Hg content of clay itself are low.The As, Se and Hg content of drinking water are lower than the natural standard of As,Se and Hg content in the drinking water.So,there are high-As content coal and high-As content coal-burning dried corn and capsicum in the endemi- c fluorosis area of Zhaotong City of Yunnan Province.The high As content of the dried corn and capsicum might have originated from the high arsenic content of burnt coal and clay.