Naturally occurring radionuclides in drinking water and their removal

The present states of a wide variety of researches on the levels and the distributions of natural radionuclides and the procedures of water purification as the measures to decrease the levels chiefly in North America were reviewed aiming to apply them in Japan to assess the risks of natural radionuclides in drinking water and of environmental pollutions due to the wastes from uranium mines. In Japan, such informations from the whole country have not sufficiently been obtained even for Radon in drinking water. So, it was thought necessary to investigate the remaining problems on the treatment of natural radionuclides and the disposal of treated wastes. Thus, it was concluded that systematic investigation on the risks of general hazardous substances in drinking water and establishment of the effective measures for these risks as well as the safety criteria should be quickly performed in our country. (M.N.). 52 refs