Lifetime excess absolute risk for lung cancer due to exposure to radon: results of the pooled uranium miners cohort study PUMA

Abstract

The Pooled Uranium Miners Analysis (PUMA) study is the largest uranium miners cohort with 119,709 miners, 4.3 million person-years at risk and 7754 lung cancer deaths. Excess relative rate (ERR) estimates for lung cancer mortality per unit of cumulative exposure to radon progeny in working level months (WLM) based on the PUMA study have been reported. The ERR/WLM was modified by attained age, time since exposure or age at exposure, and exposure rate. This pattern was found for the full PUMA cohort and the 1960 + sub-cohort, i.e., miners hired in 1960 or later with chronic low radon exposures and exposure rates. The aim of the present paper is to calculate the lifetime excess absolute risk (LEAR) of lung cancer mortality per WLM using the PUMA risk models, as well as risk models derived in previously published smaller uranium miner studies, some of which are included in PUMA. The same methods were applied for all risk models, i.e., relative risk projection up to <95 years of age, an exposure scenario of 2 WLM per year from age 18-64 years, and baseline mortality rates representing a mixed Euro-American-Asian population. Depending upon the choice of model, the estimated LEAR per WLM are 5.38 × 10^-4 or 5.57 × 10^-4 in the full PUMA cohort and 7.50 × 10^-4 or 7.66 × 10^-4 in the PUMA 1960 + sub-cohort, respectively. The LEAR per WLM estimates derived from risk models reported for previously published uranium miners studies range from 2.5 × 10^-4 to 9.2 × 10^-4. PUMA strengthens knowledge on the radon-related lung cancer LEAR, a useful way to translate models for policy purposes.

Keywords: Cohort study; Lifetime risk; Lung cancer; Mortality; Radon; Uranium miners.

Fig. 1

LEAR components by attained age (Upper part: $\text{ERR}(a)$, Bottom part: age-specific contribution to LEAR, $r_0\left(a\right)\text{ERR}(a)\tilde{S}(a)$) predicted in the full PUMA cohort (Kelly-Reif et al. , solid line) and the PUMA 1960 + sub-cohort (Richardson et al. , dashed line) for the exposure scenario of 2 working level months (WLM) per year from age 18 to 64 up to age < 95 years, assuming a 5-year lag for the BEIR VI exposure–age–concentration model, and using baseline mortality rates derived from the ICRP mixed Euro-American-Asian population (ICRP 2007)