Radon in houses: how large is the risk?

Based on the revised estimates of the average annual effective dose equivalents received from natural radiation, it is suggested that radon in houses may be responsible for some of cases of lung cancer. Moreover radon and smoking interact more than additively but less than multiplicatively in the production of lung cancer. In conclusion it is postulated that current estimates of the size of the risk associated with exposures in houses of the order of 20 Bq m-3 or about 6 % of the current lifetime risk of the incidence of lung cancer in the United Kingdom may be too high or they may be too low by a factor of two. 35 refs., 6 tabs