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The accuracy of 3D reconstruction for metrology applications using active stereo pairs depends on the quality of the calibration of the system. Active stereo pairs are generally composed of cameras mounted on tilt/pan mechanisms separated by a constant or variable baseline. This paper presents a calibration approach based on speckle metrology that allows the separation of translation and rotation in the estimation of extrinsic parameters. To achieve speckle-based calibration, a device called an Almost Punctual Speckle Source (APSS) is introduced. Using the APSS, a thorough method for the calibration of extrinsic parameters of stereo pairs is described. Experimental results obtained with a stereo system called the Agile Stereo Pair (ASP) demonstrate that speckle-based calibration achieves better reconstruction performance than methods using standard calibration procedures. Although the experiments were performed with a specific stereo pair, such as the ASP, which is described in the paper, the speckle-based calibration approach using the APSS can be transposed to other stereo setups.
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Cohorts of nuclear workers are particularly relevant to study the health effects of protracted exposures to low doses at low dose-rates of ionizing radiation (IR). In France, a cohort of nuclear workers badge-monitored for external IR exposure has been followed-up for several decades. Its size and follow-up period have recently been extended. The present paper focuses on mortality from both cancer and non-cancer diseases in this cohort. The SELTINE cohort of nuclear workers employed by CEA, Orano, and EDF companies was followed-up for mortality from 1968 to 2014. Mortality in the cohort was compared to that in the French general population. Poisson regression methods were used to estimate excess relative rates of mortality per unit of cumulative dose of IR, adjusted for calendar year, age, company, duration of employment, and socioeconomic status. The cohort included 80,348 workers. At the end of the follow-up, the mean attained age was 63 years, and 15,695 deaths were observed. A strong healthy worker effect was observed overall. A significant excess of pleural cancer mortality was observed but not associated with IR dose. Death from solid cancers was positively but non-significantly associated with radiation. Death from leukaemia (excluding chronic lymphocytic leukaemia), dementia, and Alzheimer's disease were positively and significantly associated with IR dose. Estimated dose-risk relationships were consistent with those from other nuclear worker studies for all solid cancers and leukaemia but remained associated with large uncertainty. The association between IR dose and dementia mortality risk should be interpreted with caution and requires further investigation by other studies.
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PURPOSE: The aim is to investigate associations between mortality and exposure to ionizing radiation in a cohort of uranium workers with potential for internal and external radiation exposures. METHODS: Workers employed for at least 6 months between 1958 and 2006 in five plants involved in the French nuclear fuel cycle were included and followed up between 1968 and 2013. Cause-specific standardized mortality ratios were calculated. Analyses of associations between individual cumulative radiation dose (both internal and external, lagged by 5-15 years) and mortality were conducted using Poisson regression. RESULTS: The cohort includes 4541 workers. The mean cumulative external dose was 11.12 mGy. Mean cumulative internal doses ranged, depending on modelling hypotheses, from 0.05 to 0.09 mGy (liver) and from 4.22 to 10.90 mGy (lung). At the end of the follow-up, 838 workers were deceased and 28 lost to follow-up. A healthy worker effect was observed. The risk of prostate and lung cancers mortality was significantly higher for workers exposed to cumulative external dose above 50 mGy compared to non-exposed, but these associations were based only on three cases and became non-significant, although of similar magnitude, after adjustment for smoking. Associations with internal dose showed no consistent pattern. CONCLUSIONS: For the first time, a study was conducted in a French cohort of uranium workers with a complete reconstruction of internal dose. Results are preliminary and must be interpreted with caution because of the limited cohort size and significant sources of uncertainty. Future steps of this study will overcome these limitations.
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Enfermedades Profesionales/mortalidad , Exposición Profesional/efectos adversos , Exposición a la Radiación/efectos adversos , Uranio , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte , Estudios de Cohortes , Femenino , Francia/epidemiología , Efecto del Trabajador Sano , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/mortalidad , Plantas de Energía Nuclear , Radiación Ionizante , Adulto JovenRESUMEN
OBJECTIVES: There is growing evidence of an association between low-dose external γ-radiation and circulatory system diseases (CSDs), yet sparse data exist about an association with chronic internal uranium exposure and the role of non-radiation risk factors. We conducted a nested case-control study of French AREVA NC Pierrelatte nuclear workers employed between 1960 and 2005 to estimate CSD risks adjusting for major CSD risk factors (smoking, blood pressure, body mass index, total cholesterol and glycaemia) and external γ-radiation dose. METHODS: The study included 102 cases of death from CSD and 416 controls individually matched on age, gender, birth cohort and socio-professional status. Information on CSD risk factors was collected from occupational medical records. Organ-specific absorbed doses were estimated using biomonitoring data, taking into account exposure regime and uranium physicochemical properties. External γ-radiation was measured by individual dosimeter badges. Analysis was conducted with conditional logistic regression. RESULTS: Workers were exposed to very low radiation doses (mean γ-radiation dose 2 and lung uranium dose 1 mGy). A positive but imprecise association was observed (excess OR per mGy 0.2, 95% CI 0.004 to 0.5). Results obtained after adjustment suggest that uranium exposure might be an independent CSD risk factor. CONCLUSIONS: Our results suggest that a positive association might exist between internal uranium exposure and CSD mortality, not confounded by CSD risk factors. Future work should focus on numerous uncertainties associated with internal uranium dose estimation and on understanding biological pathway of CSD after protracted low-dose internal radiation exposure.
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Enfermedades Cardiovasculares/etiología , Plantas de Energía Nuclear , Exposición Profesional/efectos adversos , Exposición a la Radiación/efectos adversos , Uranio/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/mortalidad , Estudios de Casos y Controles , Femenino , Francia/epidemiología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Exposición Profesional/estadística & datos numéricos , Exposición a la Radiación/estadística & datos numéricos , Factores de RiesgoRESUMEN
OBJECTIVES: The French nuclear worker cohort allows for the assessment of cancer risk associated with occupational radiation exposure, but workers are also exposed to medical and environmental radiation which can be of the same order of magnitude. This study aims to examine the impact of non-occupational radiation exposures on the dose-risk analysis between occupational radiation exposure and cancer mortality. METHODS: The cohort included workers employed before 1995 for at least one year by CEA, AREVA NC or EDF and badge-monitored for external radiation exposure. Monitoring results were used to calculate occupational individual doses. Scenarios of work-related X-ray and environmental exposures were simulated. Poisson regression was used to quantify associations between occupational exposure and cancer mortality adjusting for non-occupational radiation exposure. RESULTS: The mean cumulative dose of external occupational radiation was 18.4 mSv among 59 004 workers. Depending on the hypotheses made, the mean cumulative work-related X-ray dose varied between 3.1 and 9.2 mSv and the mean cumulative environmental dose was around 130 mSv. The unadjusted excess relative rate of cancer per Sievert (ERR/Sv) was 0.34 (90% CI -0.44 to 1.24). Adjusting for environmental radiation exposure did not substantially modify this risk coefficient, but it was attenuated by medical exposure (ERR/Sv point estimate between 0.15 and 0.23). CONCLUSIONS: Occupational radiation risk estimates were lower when adjusted for work-related X-ray exposures. Environmental exposures had a very slight impact on the occupational exposure risk estimates. In any scenario of non-occupational exposure considered, a positive but insignificant excess cancer risk associated with occupational exposure was observed.
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Neoplasias Inducidas por Radiación/etiología , Plantas de Energía Nuclear , Exposición Profesional/efectos adversos , Exposición a la Radiación/efectos adversos , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/epidemiología , Neoplasias Inducidas por Radiación/mortalidad , Plantas de Energía Nuclear/estadística & datos numéricos , Exposición Profesional/estadística & datos numéricos , Exposición a la Radiación/estadística & datos numéricos , Factores de RiesgoRESUMEN
PURPOSE: Epidemiological studies in cohorts of uranium millers can be informative to improve knowledge of the health effects of uranium, but are very rare. The aim of this study was to analyze, for the first time, mortality in a French cohort of uranium millers. METHODS: The F-Millers cohort includes permanent contract workers employed at least 6 months at French uranium milling plants. Vital status and causes of death were obtained from national registries between 1968 and 2013, in order to perform comparisons with French national and local mortality rates by computing standardized mortality ratios (SMRs) with 95% confidence intervals (95% CI). RESULTS: The cohort includes 1291 workers. The average duration of follow-up is 32.1 years. At the end of follow-up, 448 workers were deceased and 13 lost to follow-up. We observed a significant deficit of mortality for all causes combined when the national reference was considered (SMR 0.81; 95% CI [0.74;0.89]), but no significant difference when the local reference was considered (SMR 0.97; 95% CI [0.88;1.07]). Significant excesses were observed only in a subgroup of 552 workers hired at the manufacturing unit, mainly when the local reference was considered. CONCLUSION: No significant excess of mortality was observed at the scale of the full cohort. The cause-specific excesses of mortality observed in the subgroup of workers hired at the manufacturing unit were based on small number of cases, but would warrant further investigations. Undertaking analytical studies and combined analyses of cohorts of uranium millers would help to study the influence of potential risk factors and obtain more precise results.
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Metalurgia/estadística & datos numéricos , Mortalidad , Enfermedades Profesionales/mortalidad , Uranio , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte , Estudios de Cohortes , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
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 1,333 controls. Median positive total alpha lung dose was 2.42 mGy (mean: 8.13 mGy; maximum: 316 mGy); for plutonium the median was 1.27 mGy and for uranium 2.17 mGy. 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.See video abstract at, http://links.lww.com/EDE/B232.
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Partículas alfa/efectos adversos , Industria Procesadora y de Extracción , Neoplasias Pulmonares/mortalidad , Exposición Profesional/efectos adversos , Plutonio/efectos adversos , Uranio/efectos adversos , Anciano , Bélgica/epidemiología , Estudios de Casos y Controles , Industria Procesadora y de Extracción/estadística & datos numéricos , Femenino , Francia/epidemiología , Humanos , Neoplasias Pulmonares/etiología , Masculino , Persona de Mediana Edad , Exposición Profesional/estadística & datos numéricos , Radiometría , Factores de Riesgo , Reino Unido/epidemiologíaRESUMEN
The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation.
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Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Exposición Profesional/análisis , Traumatismos por Radiación/epidemiología , Radiobiología/métodos , Medición de Riesgo/métodos , Uranio/toxicidad , Europa (Continente)/epidemiología , Humanos , Dosis de Radiación , Radiometría/métodos , Factores de RiesgoRESUMEN
OBJECTIVES: The health effects of internal contamination by radionuclides, and notably by uranium, are poorly characterised. New cohorts of uranium workers are needed to better examine these effects. This paper analyses for the first time the mortality profile of the French cohort of uranium cycle workers. It considers mortality from cancer and non-cancer causes. METHODS: The cohort includes workers employed at least 6â months between 1958 and 2006 in French companies involved in the production of nuclear fuel. Vital status and causes of death were collected from French national registries. Workers were followed-up from 1 January 1968 to 31 December 2008. Standardised mortality ratios (SMRs) were computed based on mortality rates for the French general population. RESULTS: The cohort includes 12,649 workers (88% men). The average length of follow-up is 27â years and the mean age at the end of the study is 60â years. Large mortality deficits are observed for non-cancer causes of death such as non-cancer respiratory diseases (SMR=0.51 (0.41 to 0.63)) and circulatory diseases (SMR=0.68 (0.62 to 0.74)). A mortality deficit of lower magnitude is also observed for all cancers combined (SMR (95% CI): 0.76 (0.71 to 0.81)). Pleural mesothelioma is elevated (SMR=2.04 (1.19 to 3.27)). CONCLUSIONS: A healthy worker effect is observed in this new cohort of workers involved in the uranium cycle. Collection of individual information on internal uranium exposure as well as other risk factors is underway, to allow for the investigation of uranium-related risks.
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Neoplasias/mortalidad , Plantas de Energía Nuclear , Enfermedades Profesionales/mortalidad , Exposición Profesional/efectos adversos , Uranio/toxicidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/etiología , Enfermedades Profesionales/etiología , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVES: Until recently, enrichment of uranium for civil and military purposes in France was carried out by gaseous diffusion using rapidly soluble uranium compounds. We analysed the relationship between exposure to soluble uranium compounds and exposure to external γ-radiation and mortality in a cohort of 4688 French uranium enrichment workers who were employed between 1964 and 2006. METHODS: Data on individual annual exposure to radiological and non-radiological hazards were collected for workers of the AREVA NC, CEA and Eurodif uranium enrichment plants from job-exposure matrixes and external dosimetry records, differentiating between natural, enriched and depleted uranium. Cause-specific mortality was compared with the French general population via standardised mortality ratios (SMR), and was analysed via Poisson regression using log-linear and linear excess relative risk models. RESULTS: Over the period of follow-up, 131â 161 person-years at risk were accrued and 21% of the subjects had died. A strong healthy worker effect was observed: all causes SMR=0.69, 95% CI 0.65 to 0.74. SMR for pleural cancer was significantly increased (2.3, 95% CI 1.06 to 4.4), but was only based on nine cases. Internal uranium and external γ-radiation exposures were not significantly associated with any cause of mortality. CONCLUSIONS: This is the first study of French uranium enrichment workers. Although limited in statistical power, further follow-up of this cohort, estimation of internal uranium doses and pooling with similar cohorts should elucidate potential risks associated with exposure to soluble uranium compounds.
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Rayos gamma , Enfermedades Profesionales/mortalidad , Exposición Profesional , Compuestos de Uranio , Uranio , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Francia/epidemiología , Rayos gamma/efectos adversos , Efecto del Trabajador Sano , Humanos , Masculino , Persona de Mediana Edad , Exposición Profesional/efectos adversos , Ocupaciones , Neoplasias Pleurales/mortalidad , Solubilidad , Uranio/efectos adversos , Compuestos de Uranio/efectos adversos , Adulto JovenRESUMEN
Angelonia angustifolia Benth. is a small herbaceous plant with documented use as an anti-inflammatory remedy by indigenous cultures in Latin America. It has subsequently been developed as an ornamental annual widely available in nurseries in the United States. Chemical investigation led to the discovery that lupeol is the major organic soluble constituent in the roots, and is present in large quantities in the aerial structures of the plant. Lupeol was identified by 1D and 2D NMR spectroscopic techniques and quantified by HPLC-MS. The concentration of lupeol (9.14 mg/g in roots) in A. angustifolia is approximately 3 times higher than any previously reported sources. Therefore, the amount of lupeol in the roots of a single individual of A. angustifolia greatly exceeds the previously determined topical threshold for significant reduction of inflammation. The presence of topically therapeutic levels of lupeol in A. angustifolia provides chemical rationale for its indigenous use. In addition, the established cultivation of A. angustifolia could allow this plant to be used as a source of the important bioactive molecule lupeol, or to be developed as a nutraceutical without damaging wild populations.
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Triterpenos Pentacíclicos/química , Raíces de Plantas/química , Plantago/química , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Triterpenos Pentacíclicos/aislamiento & purificación , Plantas Medicinales/químicaRESUMEN
This article discusses the availability and completeness of medical data on workers from the AREVA NC Pierrelatte nuclear plant and their possible use in epidemiological research on cardiovascular and metabolic disorders related to internal exposure to uranium. We created a computer database from files on 394 eligible workers included in an ongoing nested case-control study from a larger cohort of 2897 French nuclear workers. For each worker, we collected records of previous employment, job positions, job descriptions, medical visits, and blood test results from medical history. The dataset counts 9,471 medical examinations and 12,735 blood test results. For almost all of the parameters relevant for research on cardiovascular risk, data completeness and availability is over 90%, but it varies with time and improves in the latest time period. In the absence of biobanks, collecting and computerising available good-quality occupational medicine archive data constitutes a valuable alternative for epidemiological and aetiological research in occupational health. Biobanks rarely contain biological samples over an entire worker's carrier and medical data from nuclear industry archives might make up for unavailable biomarkers that could provide information on cardiovascular and metabolic diseases.
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Archivos/historia , Bancos de Muestras Biológicas/historia , Monitoreo del Ambiente/historia , Plantas de Energía Nuclear/historia , Enfermedades Profesionales/historia , Traumatismos por Radiación/historia , Adulto , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/historia , Estudios de Cohortes , Monitoreo del Ambiente/estadística & datos numéricos , Femenino , Francia/epidemiología , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Masculino , Registros Médicos , Enfermedades Metabólicas/epidemiología , Enfermedades Metabólicas/historia , Persona de Mediana Edad , Enfermedades Profesionales/epidemiología , Traumatismos por Radiación/epidemiología , Uranio/toxicidad , Adulto JovenRESUMEN
This descriptive cross-sectional study examines the compliance of workers from the European Gaseous Diffusion Uranium Enrichment Consortium (EURODIF) with personal protection equipment (PPE) in view of the various hazards in the nuclear fuel industry. The PPE inventory was drawn up by an industrial hygienist in charge of the PPE at EURODIF. Two hundred and twenty seven (10%) randomly selected, active and retired, EURODIF workers filled in a questionnaire on their attitudes towards PPE. Exposure data from the EURODIF job exposure matrix were used to examine whether PPE usage varies according to exposure level. The study suggests a PPE usage profile that varies depending on the hazards present and PPE available. Anti-uranium PPE and gloves were among the best rated, while anti-spray goggles were the least used. We found that, for most hazards known to cause cancer or irreversible health damage, PPE usage varied according to exposure (homogeneity test, p<0.05; trend test, p<0.05). The continuous use of PPE among workers should be encouraged through improvements to the PPE management system. A precise model of individual exposure can only be designed if the use and efficiency of PPE are taken into consideration.
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Adhesión a Directriz/estadística & datos numéricos , Conocimientos, Actitudes y Práctica en Salud , Reactores Nucleares , Exposición Profesional/prevención & control , Equipos de Seguridad/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Industria Química , Estudios Transversales , Femenino , Fluoruros/síntesis química , Francia , Humanos , Masculino , Persona de Mediana Edad , Ropa de Protección/estadística & datos numéricos , Encuestas y Cuestionarios , Compuestos de Uranio/síntesis químicaRESUMEN
This paper describes the methods and results of an occupational exposure assessment covering 30 years of operation of the EURODIF establishment (1978-2008). The exposure assessment includes radiological, physical and chemical hazards, and takes into account of organizational changes at the establishment. Furthermore, it includes efforts to better quantify the levels of exposures using available industrial hygiene and health physics data. In total, 227 workers participated in the assessment of 26 different occupational exposures in 102 general workstations through 1978-2008. Only 7% of exposure levels were rectified by experts for internal consistency reasons. Noise, heat, trichloroethylene and soluble uranium compounds were the most prevalent exposures at the plant although their levels tended to decrease across time. Assessments of occupational exposure to noise based on JEM exposure levels were fairly well correlated with noise measurement data (Spearman's correlation coefficient, ρ=0.43) while JEM-based assessments of uranium exposure were not well correlated with uranium atmospheric measurements. This study demonstrates the importance of non-radiological exposure in the nuclear fuel industry and highlights the difficulties in managing the risks arising from these exposures. Occupational exposures remain difficult to quantify due to the scarcity of reliable monitoring data and the absence of binding occupational exposure limits for some of considered hazards.
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Metalurgia/historia , Exposición Profesional/historia , Contaminantes Ocupacionales del Aire/análisis , Contaminantes Ocupacionales del Aire/historia , Carcinógenos/análisis , Carcinógenos/historia , Polvo/análisis , Monitoreo del Ambiente , Francia , Historia del Siglo XX , Historia del Siglo XXI , Calor , Humanos , Mutágenos/análisis , Mutágenos/historia , Ruido , Exposición Profesional/análisis , Dosis de Radiación , Teratógenos/análisis , Teratógenos/historia , Uranio/análisis , Uranio/historiaRESUMEN
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. The mortality observed in each population was compared with that expected from national mortality statistics, by computing standardized mortality ratios. Dose-effect relationships were analyzed through trend tests and log-linear Poisson regressions. RESULTS: 14,796 workers were exposed only to external photon radiation; 14,408 workers were also potentially exposed to internal radiation or to neutrons. Between 1968 and 1994, the number of deaths is respectively, 645 and 1,197. The mean external photon dose was respectively, 3.7 and 12.9 mSv. Similar Healthy Worker Effects were observed in the two populations (SMR = 0.59). SMR of 2.41 90% CI [1.39-3.90] was observed for malignant melanoma among workers of the second population. Significant dose-effect relationships were observed: among workers exposed only to external photon radiation for leukemia except CLL and in the other population, for cancers and other diseases related to tobacco or alcohol consumption. CONCLUSIONS: Results differed between the two populations. The increase in leukemia risk with dose in the first population will have to be confirmed with extended follow-up. In the other population, results may have been confounded by alpha-emitters inhalation, tobacco, or alcohol consumption.
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Neoplasias Inducidas por Radiación/mortalidad , Enfermedades Profesionales/mortalidad , Exposición Profesional/efectos adversos , Fotones , Traumatismos por Radiación/mortalidad , Adulto , Factores de Confusión Epidemiológicos , Relación Dosis-Respuesta en la Radiación , Femenino , Francia/epidemiología , Humanos , Leucemia/etiología , Leucemia/mortalidad , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/etiología , Enfermedades Profesionales/etiología , Exposición Profesional/análisis , Traumatismos por Radiación/etiologíaRESUMEN
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). Trend and heterogeneity tests were computed in order to study SMRs variation by job characteristics. In the bioCEA cohort individual dosimetry data being available, a trend test was also computed according to ionizing radiation cumulative dose. RESULTS: The SMRs were significantly below one in both cohorts for all-cause mortality (bioCEA: SMR = 0.52 [0.46-0.59], bioINSERM: SMR = 0.56 [0.46-0.67]) and for all-cancer mortality (bioCEA: SMR = 0.66 [0.54-0.80], bioINSERM: SMR = 0.55 [0.39-0.75]). There were some specific cancer sites for which the SMR was higher than 1, but not significantly. In the bioCEA cohort a positive trend was observed between ionizing radiation cumulative doses and all-cause as well as all-cancer SMRs. CONCLUSION: This study on two French cohorts of biological research workers found a favorable mortality pattern. These findings are consistent with recent publications. The positive trend of cancer mortality according to ionizing radiation exposure among bioCEA cohort needs to be confirmed with more precise assessment of exposures and information on individual risk factors.
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Carcinógenos Ambientales/efectos adversos , Personal de Laboratorio Clínico , Neoplasias Inducidas por Radiación/mortalidad , Enfermedades Profesionales/mortalidad , Exposición Profesional/efectos adversos , Adulto , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Energía Nuclear , Dosis de Radiación , Medición de RiesgoRESUMEN
In Saccharomyces cerevisiae, the double-stranded-RNA-specific RNase III (Rnt1p) is required for the processing of pre-rRNA and coprecipitates with transcriptionally active rRNA gene repeats. Here we show that Rnt1p physically interacts with RNA polymerase I (RNAPI) and its deletion decreases the transcription of the rRNA gene and increases the number of rRNA genes with an open chromatin structure. In contrast, depletion of ribosomal proteins or factors that impair RNAPI termination did not increase the number of open rRNA gene repeats, suggesting that changes in the ratio of open and closed rRNA gene chromatin is not due to a nonspecific response to ribosome depletion or impaired termination. The results demonstrate that defects in pre-rRNA processing can influence the chromatin structure of the rRNA gene arrays and reveal links among the rRNA gene chromatin, transcription, and processing.