The distribution of radioactive pollutants, such as ^(222)Rn, U, Th and ^(226)Ra in the air, sur- face waters, soils and crops around the Lincang uranium mine, Yunnan Province, China, is studied The mechanical, geochemical and biogeochemical processes responsible for the transport and fate of the radioactive elements are discussed based on the monitoring data. The pollutants con- centrations of effluents from the mine tunnels were dependent on pH and SO_4^(2-) which were con- trolled by biochemical oxidation of sulfide in the ore/host rocks. Radon anomalies in air reached 4 km from the tailings pile depending on radon release from the site, topography and climate. ^(238)U and ^(226)Ra abnormities in stream sediments and soil were 40-90 cm deep and 790-800 m away downstream. Anomalies of radioactive contaminants of surface watercourses extended 7.5-13 km from the discharge of effluents of the site mainly depending on mechanical and chemical proc- esses. There were about 2.86 ha rice fields and 1.59 km stream sediments contaminated. Erosion of tailings and mining debris with little or no containment or control accelerated the contamination processes.
