Original article

Scand J Work Environ Health 2010;36(5):373-383    pdf


Mortality from circulatory system diseases and low-level radon exposure in the French cohort study of uranium miners, 1946–1999

by Nusinovici S, Vacquier B, Leuraud K, Metz-Flamant C, Caër-Lorho S, Acker A, Laurier D

Objectives The few studies examining the risk of circulatory system diseases (CSD) associated with ionizing radiation have reported inconsistent results. Radon, a known pulmonary carcinogen, emits ionizing radiation. The aim of this study was to examine CSD mortality in a French cohort of uranium miners and evaluate the plausibility of an association with radon exposure.

Methods The cohort included men employed as uranium miners for ≥1 year between 1946–1990. We obtained vital status and cause of death from national registers and reconstructed radon exposure for each year. Exposure­–risk relations were estimated with a linear excess relative risk (ERR) model using a 5-year lag time.

Results The cohort comprised 5086 miners, followed up for a mean duration of 30.1 years. The average cumulative exposure of the radon-exposed miners was 36.6 working level months (WLM). A total of 1411 deaths were observed, including 319 deaths due to CSD. No excess risk was found for this overall cause of death. A significant positive trend was observed between deaths from cerebrovascular diseases (CeVD) and cumulative radon exposure, together with a significant ERR per 100 WLM [ERR per 100 WLM 0.49, 95% confidence interval (95% CI) 0.07–1.23)]. Hard physical activity was identified as a potential modifying factor of the exposure–risk relation.

Conclusions For the first time in a cohort of uranium miners, our results suggest an association between CeVD mortality and cumulative radon exposure. Due to a lack of data, which limited our ability to assess possible confounding by cardiovascular risk factors, these findings should be interpreted with caution.

This article refers to the following texts of the Journal: 1997;23(3):221-226  1989;15(3):165-179