Low radon exposures and lung cancer risk: joint analysis of the Czech, French, and Beaverlodge cohorts of uranium miners.

It is well established that high radon exposures increase the risk of lung cancer mortality. The effects of low occupational exposures and the factors that confound and modify this risk are not clear and are needed to inform current radiation protection of miners. The risk of lung cancer mortality at low radon exposures (< 100 working-level months) was assessed in the joint cohort analysis of Czech, French, and Canadian uranium miners, employed in 1953 or later. Statistical analysis was based on linear Poisson regression modeling with grouped cohort survival data. Two sensitivity analyses were used to assess potential confounding from tobacco smoking. A statistically significant linear relationship between radon exposure and lung cancer mortality was found. The excess relative risk per working-level month was 0.022 (95% confidence intervals: 0.013-0.034), based on 408 lung cancer deaths and 394,236 person-years of risk. Time since exposure was a statistically significant modifier; risk decreased with increasing time since exposure. A tendency for a decrease in risk with increasing attained age was observed, but this was not statistically significant. Exposure rate was not found to be a modifier of the excess relative risk. The potential confounding effect of tobacco smoking was estimated to be small and did not substantially change the radon-lung cancer mortality risk estimates. This joint cohort analysis provides strong evidence for an increased risk of lung cancer mortality from low occupational radon exposures. The results suggest that radiation protection measures continue to be important among current uranium miners

Lung cancer risk from radon and radon progeny. Epidemiological studies

International audienceRadon is a radioactive gas of natural origin, coming from the disintegration of uranium from the soil which concentrates in confined places. The inhaled radon gas deposits on the respiratory tract surface where short-lived progenies decay by emitting alpha particles mainly. Epidemiological studies have been conducted among miners and the general population to assess the mortality risk from lung cancer associated with occupational and indoor exposure to radon respectively. Cohorts of uranium miners have clearly established an increased risk of lung cancer associated with cumulative radon exposure. This relation has been also investigated through a dosimetric approach in European cohorts of uranium miners, where the lung cancer risk was significantly associated with the lung dose, knowing that radon progenies represented more than 97% of the alpha lung dose (compared to the contribution of long-lived radionuclides or external gamma rays). The analysis of time-dependent modifying factors showed a decrease of the risk with time since exposure and attained age. The association remained significant after taking into account for smoking status, and studies are in favor of a sub-multiplicative interaction between radon and smoking. Some individual cohorts also suggested that the association remained significant when considering low level of radon or after adjustment on other confounding exposures, such as uranium ore dust, external gamma rays or chest X-ray examination. Lung cancer risk from residential radon exposure has been estimated from about twenty case-control studies. Individual studies have limited power, but three combined analyses conducted among of European, North American and Chinese studies clearly demonstrated an increase of lung cancer risk associated with residential radon exposure. A significant association was also observed for radon exposure under 200 Bq/m3 and the risk remained significant after adjustment on smoking status. In a general way, most of the individual studies still suffer of a lack of statistical power and the risk-exposure relationship deserves to be refined. Currently, a large international project, the PUMA study, is setting up to include more than 120.000 uranium miners arising from seven cohorts. This project will particularly allow to better address questions concerning low exposure and low exposure rate effects, to have greater ability to describe temporal modifiers, and to better quantify the impact of radon progeny versus other radiological exposures present in uranium mines

Lung cancer risk from radon and radon progeny. Epidemiological studies

International audienceRadon is a radioactive gas of natural origin, coming from the disintegration of uranium from the soil which concentrates in confined places. The inhaled radon gas deposits on the respiratory tract surface where short-lived progenies decay by emitting alpha particles mainly. Epidemiological studies have been conducted among miners and the general population to assess the mortality risk from lung cancer associated with occupational and indoor exposure to radon respectively. Cohorts of uranium miners have clearly established an increased risk of lung cancer associated with cumulative radon exposure. This relation has been also investigated through a dosimetric approach in European cohorts of uranium miners, where the lung cancer risk was significantly associated with the lung dose, knowing that radon progenies represented more than 97% of the alpha lung dose (compared to the contribution of long-lived radionuclides or external gamma rays). The analysis of time-dependent modifying factors showed a decrease of the risk with time since exposure and attained age. The association remained significant after taking into account for smoking status, and studies are in favor of a sub-multiplicative interaction between radon and smoking. Some individual cohorts also suggested that the association remained significant when considering low level of radon or after adjustment on other confounding exposures, such as uranium ore dust, external gamma rays or chest X-ray examination. Lung cancer risk from residential radon exposure has been estimated from about twenty case-control studies. Individual studies have limited power, but three combined analyses conducted among of European, North American and Chinese studies clearly demonstrated an increase of lung cancer risk associated with residential radon exposure. A significant association was also observed for radon exposure under 200 Bq/m3 and the risk remained significant after adjustment on smoking status. In a general way, most of the individual studies still suffer of a lack of statistical power and the risk-exposure relationship deserves to be refined. Currently, a large international project, the PUMA study, is setting up to include more than 120.000 uranium miners arising from seven cohorts. This project will particularly allow to better address questions concerning low exposure and low exposure rate effects, to have greater ability to describe temporal modifiers, and to better quantify the impact of radon progeny versus other radiological exposures present in uranium mines

Pollution atmosphérique et sévérité de l'asthme chez 371 sujets adultes asthmatiques de l'étude EGEA

Peu d'études ont porté sur les effets de la pollution atmosphérique à long terme sur la sévérité de l'asthme. L'objectif de ce travail était d'étudier la relation entre la pollution atmosphérique des douze derniers mois et la sévérité de l'asthme chez 371 sujets adultes asthmatiques de l'enquête EGEA (Etude épidémiologique des facteurs génétiques et environnementaux de l'asthme) et d'évaluer la faisabilité de l'estimation de l'exposition à la pollution atmosphérique. L'estimation de l'exposition moyenne au cours des 12 derniers mois au dioxyde d'azote, dioxyde de soufre et à l'ozone a pu être réalisée pour la majorité des sujets. L'étude a montré une association significative entre l'ozone et le score clinique de sévérité de l'asthme et un score combiné prenant en compte le traitement qui persistait après ajustement sur différents facteurs. Les résultats étayent l'hypothèse avancée par les études de panel selon laquelle la pollution atmosphérique augmente la sévérité de l'asthme.CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

REJETS DES MOTEURS DIESEL ET IMPACT SUR LA SANTE PUBLIQUE

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Phénotypes associés à l'asthme et pollution atmosphérique dans l'étude EGEA

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocSudocFranceF

Miner studies and radiological protection against radon

International audienceMajor results on radon associated health risk have been provided by epidemiological studies of miners. In total, about 15 studies have been conducted worldwide since the 1960’s. These results contributed directly to radiological protection against radon. The present article summarizes the mains results, with a focus on analyses of miners exposed in recent periods, estimates of radon lifetime attributable risk, and interaction between radon and smoking. Perspectives opened by the PUMA (Pooled Uranium Miner Analysis) project are discussed