|I heard that ICRP is dealing with a new evaluation and new recommendations for radon. Especially I am concerned about the recommendation in the draft that there should be no attempt to reduce exposures in domestic dwellings below 600 Bq/m³.
I have difficulties to understand this recommendation in the light of the recent results of the big pooling studies in Europe and the US including many thousand cases and controls. The results of the north American pooling study (Krewski et al. Epidemiology, in press) and the German pooling study (Wichmann et al., Health Physics, in press) show an Excess Relative Risk of about 0.1 per 100 Bq/m³. In addition, the German study has an elevated Relative Risk of 1.40 for radon concentrations above 140 Bq/m³ (see enclosed manuscript). Meanwhile also the European pooling study is completed (Darby et al., submitted).
Obviously it would be essential for the work of ICRP to include this material in the review process. I am sure that Drs. Darby and Krewski are willing to share their manuscripts with you.
The figure of 600 Bq/m³ is the value where ICRP considers that remedial action is certainly warranted. We expect national authorities to optimise the level of protection to be achieved - which has to be a national process, taking account of the costs and number of dwellings involved. The resulting levels after remediation are expected to be down to around 200 Bq/m³, but it does depend on the country. We will hope to use the papers to which you referred.