Host: The Japan Radiation Research Society
Co-host: Asian Association for Radiation Research
Among various sources of natural radiation, the most important is radon gas exposure. UNSCEAR report 2000 has pointed out that radon exposure accounts for about half of natural radiation exposure among men. High-level radon exposure is well known to inclrease lung cancer risk as reported from studies among uranium miners and others. Recently, it has been strongly suspected that indoor exposure to radon levels as high as 100-200 Bq/m3 may also increase lung cancer risk among residents. WHO is now argueing that residential radon exposure is an important risk of lung cancer in addition to smoking, and has launched an international project on this problem, suspecting that such an exposure is an important Global Burden of Disease. At the First Meeting of the Expert Group for the WHO Project on Residential Radon Risk in last January, the results of two pooled analyses, one in North America and the other in Europe, were presented and their public health implications were discussed. In the present study, a brief summary of those studies will presented, problems regarding epidemiological studies on the relatiohship between radon expsoure and lung cancer risk will be discussed, and future direction of residential radon studies will be proposed.