In order to evaluate the environmental impact of U anormaly in the drainage system around the Shinbo talc mine area, U contents, their distribution patterns, bioaccumulation and α-radioactivity in stream water, stream sediments and aquatic organisms were investigated. The U contents of stream water attenuated with increasing distance from the mine area. The same attenuation pattern is shown in stream sediments from mine to 0.75 ㎞ downstream, although these contain highly enriched U contents (24∼83 ㎎/㎏) comparing with the international average concentration of surface soils (0.79∼11 ㎎/㎏). However, U content increases aburptly in sediment at 1.5 ㎞ downstream, probably dut to detrital migration and rediposition of U enriched sediments. Futhermore, enriched U in downstream sediments occur in high proportions of carbonate and Fe-Mn oxide bounded forms, which show high potential of a secondary pollution source. for aquatic organiosms, bio accumulation degree of U are in the order: aquatic larvae>black snail>mountain frog>crawfish. Cultured trout by the U enrich groundwater (387 μg/ℓ) shows U accumulation in the part of branchia (CRs 5.25) and bones (CRs 11.2) but not in flesh (CRs 0.03). Total α-radioactivity have been measured in the level as 0.47 nCi/l for groundwater, 2.94∼18 nCi/㎏ㆍDW for organisms and 93∼328 nCi/㎏ㆍDW for sediments.
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