Risk of lung cancer mortality in nuclear workers from internal exposure to alpha particle-emitting radionuclides
Couplée à des cohortes belge, française et britannique de salariés travaillant dans l'industrie de l'uranium et du plutonium et portant sur 553 patients décédés d'un cancer du poumon et sur 1 333 témoins, cette étude évalue l'association entre une exposition à des radionucléides émettant des rayonnements alpha, le risque de développer la maladie et la mortalité spécifique
Background: Carcinogenic risks of internal exposures to alpha-emitters (except radon) are poorly understood. Since exposure to alpha particles-particularly through inhalation-occurs in a range of settings, understanding consequent risks is a public health priority. We aimed to quantify dose-response relationships between lung dose from alpha-emitters and lung cancer in nuclear workers. Methods: We conducted a case-control study, nested within Belgian, French, and UK cohorts of uranium and plutonium workers. Cases were workers who died from lung cancer; one to three controls were matched to each. Lung doses from alpha-emitters were assessed using bioassay data. We estimated excess odds ratio (OR) of lung cancer per gray (Gy) of lung dose. Results: The study comprised 553 cases and 1333 controls. Median positive total alpha lung dose was 2.42mGy (mean: 8.13mGy; maximum: 316mGy); for plutonium the median was 1.27mGy and for uranium 2.17mGy. Excess OR/Gy (90% confidence interval)-adjusted for external radiation, socioeconomic status, and smoking-was 11 (2.6, 24) for total alpha dose, 50 (17, 106) for plutonium, and 5.3 (1.9, 18) for uranium. Conclusions: We found strong evidence for associations between low doses from alpha-emitters and lung cancer risk. The excess OR/Gy was greater for plutonium than uranium, though confidence intervals overlap. Risk estimates were similar to those estimated previously in plutonium workers, and in uranium miners exposed to radon and its progeny. Expressed as risk/equivalent dose in sieverts (Sv), our estimates are somewhat larger than but consistent with those for atomic bomb survivors.