Radon carcinogenesis: risk data and cellular hits.

Abundant epidemiological data are now available (2008) on the human lung cancer response for lifetime radon gas exposure to residential concentrations of 100 Bq m(-3), equal to 22 working level months over 40 y. We combined published pooled epidemiological data and dosimetric calculations of alpha particle hits to target basal or mucous cell nuclei in bronchial epithelium. This yields an estimate that about 10,000 basal nuclei (target) cell hits per cm2 per person over a lifetime are involved in radon-related lung cancer.