Risk of Lung Cancer Mortality in Nuclear Workers from Internal Exposure to Alpha Particle-emitting Radionuclides.

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.

RADON DOSIMETRY FOR WORKERS: ICRP'S APPROACH.

The International Commission on Radiological Protection (ICRP) has recently published two reports on radon exposure; Publication 115 on lung cancer risks from radon and radon progeny and Publication 126 on radiological protection against radon exposure. A specific graded approach for the control of radon in workplaces is recommended where a dose assessment is required in certain situations. In its forthcoming publication on Occupational Intakes of Radionuclides (OIR) document, Part 3, effective dose coefficients for radon and thoron will be provided.

Doses and lung cancer risks from exposure to radon and plutonium.

Purpose: Epidemiological studies of the French uranium miners and the plutonium workers at the Mayak nuclear facility have provided excess relative risk (ERR) estimates per unit absorbed lung dose from alpha radiation. The aim of this paper was to review these two studies and to derive values of the relative biological effectiveness (RBE) of alpha particles for the induction of lung cancer.

Materials And Methods: We examined and compared the dosimetry assumptions and methodology used in the epidemiological studies of uranium miners and the plutonium workers.

Cancer mortality among two different populations of French nuclear workers.

Purpose: The aim of this paper is to study the effect of external photon radiation on the mortality of two populations of French nuclear workers: workers exposed only to external photon radiation and workers potentially exposed also to internal contamination or to neutrons.

Method: External photon radiation has been measured through individual dosimeters. Potential exposure to internal contamination or to neutrons has been assessed by experts on the basis of quantitative measurements or of worksite and type of activity.

Dose conversion factors for radon: recent developments.

Epidemiological studies of the occupational exposure of miners and domestic exposures of the public have provided strong and complementary evidence of the risks of lung cancer following inhalation of radon progeny. Recent miner epidemiological studies, which include low levels of exposure, long duration of follow-up, and good quality of individual exposure data, suggest higher risks of lung cancer per unit exposure than assumed previously by the International Commission on Radiological Protection (ICRP). Although risks can be managed by controlling exposures, dose estimates are required for the control of occupational exposures and are also useful for comparing sources of public exposure.

Reprocessed uranium exposure and lung cancer risk.

This study investigated the risk of lung cancer in regards to protracted occupational exposure to reprocessed uranium compounds. Two thousand seven hundred and nine male workers employed at the AREVA NC uranium processing plant between 1960 and 2005 in France were included in the cohort. Historical exposure to reprocessed uranium compounds classified by their solubility type was assessed on the basis of the plant's specific job-exposure matrix.

French cohort of the uranium processing workers: mortality pattern after 30-year follow-up.

Objective: To investigate mortality among nuclear workers with potential internal exposure to uranium.

Methods: The cohort included 2,709 workers employed at the AREVA NC Pierrelatte plant for at least 6 months (72,787 person-years). This plant processed uranium enrichment during the period 1960-1996 and chemical conversion since 1980.

Human exposure to high natural background radiation: what can it teach us about radiation risks?

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of (222)Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation.

Comparative assessing for radiological, chemical, and physical exposures at the French uranium conversion plant: Is uranium the only stressor?

This study presents the pattern of exposure to uranium and other occupational pollutants known to be potentially carcinogenic, mutagenic or toxic and used at the main uranium conversion plant in France. For different uranium compounds specified according to their solubility and purity, and 16 other categories of pollutants: chemicals, fibres, vapours, dust, and heat a time- and plant-specific job exposure matrix (JEM) was created covering the period 1960-2006. For 73 jobs and for each pollutant the amount and frequency of exposure were assessed on a four-level scale by different time periods.

Lung cancer in French and Czech uranium miners: Radon-associated risk at low exposure rates and modifying effects of time since exposure and age at exposure.

Radon is recognized as a public health concern for indoor exposure. Precise quantification derived from occupational exposure in miners is still needed for estimating the risk and the factors that modify the dependence on cumulated exposure. The present paper reports on relationship between radon exposure and lung cancer risk in French and Czech cohorts of uranium miners (n = 10,100).

Cancer risk in nuclear workers occupationally exposed to uranium-emphasis on internal exposure.

Workers involved in the nuclear fuel cycle have a potential for internal exposure to uranium. The present review of epidemiological studies of these workers aims to elucidate the relationship between occupational internal uranium exposure and cancer risk. Eighteen cohort and 5 nested case-control studies published since 1980 are reviewed.

Cancer mortality risk among biology research workers in France: first results of two retrospective cohorts studies.

Objective: To investigate all-cause and cancer mortality of biological research laboratories workers of the French Atomic Energy Commission (CEA) and the National Institute of Health and Medical Research (INSERM).

Methods: Two cohorts, bioCEA (N = 3,509) and bioINSERM (N = 4,966) were followed from 1968 to 1994 and 1980 to 1993, respectively. The mortality of each cohort was compared with that of the French population by computation of the standardized mortality ratio (SMR) with their 90% confidence interval (90% CI).

Down syndrome time-clustering in January 1987 in Belarus: link with the Chernobyl accident?

The Chernobyl accident (April 26, 1986) exposed a large part of the Belarus population to ionizing radiation. We analyzed the time trends of Down syndrome (DS) in Belarus to evaluate whether either brief exposure at high dose rates during the plume passage or continuous exposure at low doses and dose rates of the residents of contaminated areas had any detectable impact on DS prevalence at birth. DS data came from the Belarus National Registry of Congenital Malformations (1981-2001).

Lung cancer risk associated to exposure to radon and smoking in a case-control study of French uranium miners.

A case-control study nested in the cohort of French uranium miners took smoking information into account in investigating the effect of radon exposure on lung cancer risk. This study included 100 miners who died of lung cancer and 500 controls matched for birth period and attained age. Data about radon exposure came from the cohort study, and smoking information was retrospectively determined from a questionnaire and occupational medical records.

Lung cancer attributable to indoor radon exposure in france: impact of the risk models and uncertainty analysis.

Objective: The inhalation of radon, a well-established human carcinogen, is the principal-and omnipresent-source of radioactivity exposure for the general population of most countries. Scientists have thus sought to assess the lung cancer risk associated with indoor radon. Our aim here is to assess this risk in France, using all available epidemiologic results and performing an uncertainty analysis.

Childhood leukemia incidence and exposure to indoor radon, terrestrial and cosmic gamma radiation.

This study was undertaken to evaluate the ecological association between terrestrial and cosmic gamma radiation, indoor radon, and acute leukemia incidence among children under 15 y of age. From 1990 to 2001, 5,330 cases of acute leukemia were registered by the French National Registry of Childhood Leukemia and Lymphoma. Exposure to terrestrial gamma radiation was based on measurements, using thermoluminescent dosimeters, at about 1,000 sites covering all the "Départements.

Residential radon and lung cancer--detailed results of a collaborative analysis of individual data on 7148 persons with lung cancer and 14,208 persons without lung cancer from 13 epidemiologic studies in Europe.

Objectives: Studies seeking direct estimates of the lung cancer risk associated with residential radon exposure lasting several decades have been conducted in many European countries. Individually these studies have not been large enough to assess moderate risks reliably. Therefore data from all 13 European studies of residential radon and lung cancer satisfying certain prespecified criteria have been brought together and analyzed.

Uncertainty and sensitivity analysis in assessment of the thyroid cancer risk related to Chernobyl fallout in Eastern France.

The increase in the thyroid cancer incidence in France observed over the last 20 years has raised public concern about its association with the 1986 nuclear power plant accident at Chernobyl. At the request of French authorities, a first study sought to quantify the possible risk of thyroid cancer associated with the Chernobyl fallout in France. This study suffered from two limitations.

Projecting the time trend of thyroid cancers: its impact on assessment of radiation-induced cancer risks.

The incidence of thyroid cancer, which may be induced by ionizing radiation, has been rising in most Western countries for more than 20 years. In France, public worry about this increase and its possible connection with the fallout from Chernobyl led the government to ask for an evaluation of the health impact of this accident and an assessment of the feasibility of an epidemiological study. These requests raise two methodological questions: Which risk model should be used to relate exposure to risk? What is known about the spontaneous incidence rate of thyroid cancers? This article analyzes the impact of the time trend in the spontaneous incidence of thyroid cancers over the past 20 years in France when evaluating the risk of radiation-induced cancer.

Indoor radon and lung cancer in France.

Background: Several case-control studies have indicated an increased risk of lung cancer linked to indoor radon exposure; others have not supported this hypothesis, partly because of a lack of statistical power. As part of a large European project, a hospital-based case-control study was carried out in 4 areas in France with relatively high radon levels.

Methods: Radon concentrations were measured in dwellings that had been occupied by the study subjects during the 5- to 30-year period before the interview.

Radon-induced lung cancer in French and Czech miner cohorts described with a two-mutation cancer model.

A two-mutation carcinogenesis model with clonal expansion of pre-malignant cells is used to describe lung cancer mortality data from studies on French and Czech miners with relatively low exposures to radon. The aim was to derive radon-induced lung cancer risk estimates applicable to different populations using a model description consistent with both cellular dose-response relationships, and previous model analyses of animal and human epidemiological data. The significantly different baseline lung cancer risks for the two cohorts that include the effects from the unknown smoking habits, are described with different background model parameters.

An update of cancer mortality among the French cohort of uranium miners: extended follow-up and new source of data for causes of death.

The follow-up of the French cohort of uranium miners has been extended to 1994, and a new source of information for causes of death has been used. The paper presents the new results regarding the risk of death among the cohort, and analyses the impact of the methodological changes on these results. The extension of the follow-up results in a substantial increase in statistical power compared with previous analysis (+25% for person-years and +74% for the number of deaths).