Mortality from circulatory system diseases and low-level radon exposure in the French cohort study of uranium miners, 1946-1999.
OBJECTIVE
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.
Nusinovici
Simon
S
Institut de Radioprotection et de Sûreté Nucléaire, DRPH/SRBE/LEPID, BP17, 92262 Fontenay aux Roses, France.
Vacquier
Blandine
B
Leuraud
Klervi
K
Metz-Flamant
Camille
C
Caër-Lorho
Sylvaine
S
Acker
Alain
A
Laurier
Dominique
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000401:mortality*; D015331:Cohort Studies; D016001:Confidence Intervals; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008906:Mining; D015233:Models, Statistical; D009784:Occupational Diseases / Q000453:epidemiology / Q000401:mortality*; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health / Q000706:statistics & numerical data; D011886:Radon / Q000633:toxicity*; D012306:Risk; D018570:Risk Assessment; D014501:Uranium / Q000633:toxicity*
D014501:Uranium; D011886:Radon