BACKGROUND: This study aims to estimate the association between radon and site-specific cancer mortality among a large contemporary cohort of male uranium miners. METHODS: Annual occupational radon exposure was estimated based on a worker's duration of underground mining in a year and estimates of potential alpha energy of radon progeny in their location of work. Cancer mortality over the period 1977-1992 was ascertained for a cohort of 16 434 male underground uranium miners employed in the Czech Republic between 1946 and 1992. Poisson regression was used to estimate relationships between cumulative radiation exposure (in working level months [WLM]) and site-specific cancer mortality. RESULTS: Radon is positively associated with lung cancer mortality (excess relative rate [ERR] per 100 WLM = 0.2; 95% confidence interval [CI]: 0.10, 0.37). The best fit of the dose-response relationship between radon and lung cancer mortality was linear and estimates of radon-lung cancer associations varied by windows of time-since-exposure. Positive associations between radon and several types of cancer other than lung cancer were identified, notably chronic lymphocytic leukemia (CLL) (ERR/100 WLM = 0.24; 95% CI: [not determined [ND], 5.10]) and extrathoracic cancer (ERR/100 WLM = 0.12; 95% CI: [ND, 0.69]). We observed no associations between radon and stomach cancer, nor between radon and several hematopoietic cancer subtypes. CONCLUSIONS: This study confirms the established radon-lung cancer association and suggests that radon may also be associated with other types of cancer mortality. Further investigations of extrathoracic and CLL cancer, with the aim of obtaining more precise estimates, are warranted to understand associations between radon and cancers other than lung.

• Klíčová slova
• cancer, lung cancer, radon, uranium mining,
• MeSH
• chronická lymfatická leukemie etiologie   mortalita   MeSH
• hornictví * MeSH
• lidé MeSH
• nádory plic etiologie   mortalita   MeSH
• nádory vyvolané zářením mortalita   MeSH
• nemoci z povolání etiologie   mortalita   MeSH
• Poissonovo rozdělení MeSH
• pracovní expozice škodlivé účinky   MeSH
• radon toxicita   MeSH
• uran * MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, N.I.H., Intramural MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• radon MeSH
• uran * MeSH

The aim of the present study was to evaluate the risk of lung cancer from combined exposure to radon and smoking. Methodologically, it is based on case-control studies nested within two Czech cohort studies of nearly 11,000 miners followed-up for mortality in 1952-2010 and nearly 12,000 inhabitants exposed to high levels of radon in homes, with mortality follow-up in 1960-2010. In addition to recorded radon exposure, these studies use information on smoking collected from the subjects or their relatives. A total of 1,029 and 370 cases with smoking information have been observed in the occupational and environmental (residential) studies, respectively. Three or four control subjects have been individually matched to cases according to sex, year of birth, and age. The combined effect from radon and smoking is analyzed in terms of geometric mixture models of which the additive and multiplicative models are special cases. The resulting models are relatively close to the additive interaction (mixing parameter 0.2 and 0.3 in the occupational and residential studies, respectively). The impact of the resulting model in the residential radon study is illustrated by estimates of lifetime risk in hypothetical populations of smokers and non-smokers. In comparison to the multiplicative risk model, the lifetime risk from the best geometric mixture model is considerably higher, particularly in the non-smoking population.

• MeSH
• hornictví MeSH
• kouření škodlivé účinky   MeSH
• lidé MeSH
• nádory plic epidemiologie   etiologie   MeSH
• radioaktivní látky znečišťující vzduch škodlivé účinky   MeSH
• radon škodlivé účinky   MeSH
• riziko MeSH
• studie případů a kontrol MeSH
• uran MeSH
• vystavení vlivu životního prostředí škodlivé účinky   analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• radioaktivní látky znečišťující vzduch MeSH
• radon MeSH
• uran MeSH

A brief description is given of the study of West Bohemian uranium miners, and recent and ongoing efforts to improve the quality of the data are summarized. Three recent analyses of the data from the cohort have led to rather different estimates of the excess relative risk of mortality from lung cancer per working-level month. The reasons for these different estimates are described, and it is concluded that estimates of lung cancer risk are strongly influenced by the quality of the exposure estimates, especially by the omission of some exposures accumulated during employment at other uranium mines, following the closure of most of the shafts at the original two mines. The most recent analysis has shown that, in common with other cohorts of radon-exposed miners, the excess relative risk of lung cancer per working-level month is modified by age and time since exposure. An inverse effect of exposure rate was also demonstrated, but it affected only men at very high concentrations and appears to be related to the time pattern of exposure. In addition, the risk was found to differ between the two main mines, possibly due to the influence of arsenic in the dust of the mines.

• MeSH
• hornictví * MeSH
• kohortové studie MeSH
• lidé MeSH
• nádory plic etiologie   MeSH
• nádory vyvolané zářením etiologie   MeSH
• radon škodlivé účinky   MeSH
• riziko MeSH
• uran MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• radon MeSH
• uran MeSH

A cohort of 4320 uranium miners in West Bohemia who started work at the mines during 1948 to 1959 and worked there for at least four years were followed up to the end of 1990 to determine cause specific mortality risks in relation to exposures in the mines. The miners had experienced high radon exposures, on average 219 working level months during their uranium mining careers, for which detailed measurements were available. They had also been exposed to high arsenic levels in one of the two major mines, and to dust. New follow up methods, not previously used for occupational cohorts in Czechoslovakia, were utilised. By the end of follow up 2415 (56%) of the cohort were known to have died. Overall mortality was significantly raised compared with that in the general population (relative risk (RR) = 1.56, 95% confidence interval (95% CI) 1.50-1.63), with significantly raised risks of lung cancer (RR = 5.08, 95% CI 4.71-5.47), accidents (RR = 1.59, 95% CI 1.34-1.87), homicide (RR = 5.57, 95% CI 2.66-10.21), mental disorders (RR = 5.18, 95% CI 2.83-8.70), cirrhosis (RR = 1.51, 95% CI 1.16-1.94), and non-rheumatic circulatory diseases (RR = 1.16, 95% CI 1.08-1.25). The relative risk of lung cancer was greatest four to 14 years after entry to the mines. Relative risks for homicide and accidents were raised up to 25 years from entry but not after this. Substantial significantly raised risks at 15 to 24 years after entry occurred for cirrhosis, non-rheumatic circulatory diseases,a nd pneumonia and other respiratory infections. Sizeable significantly raised risks at 25 and more years after entry, but not earlier, were present for mental disorders, tuberculosis, and non-malignant non-infectious respiratory conditions. No specific causes showed risks significantly related to age at entry to mining. Risk of lung cancer was significantly positively related to radon exposure, estimated arsenic exposure, and duration of work in the mines, but no other cause was significantly positively related to these variables. The raised risk of lung cancer in uranium miners, which is well established, is related aetiologically to radon exposure, and in the present cohort it may also in part have been due to exposure to arsenic. The raised risks of accidents, tuberculosis, and non-infectious respiratory diseases have also been seen in other uranium mining cohorts, and are likely to reflect the dangerous and dusty working conditions and the confined spaces in which work occurred. The cirrhosis and homicide deaths probably related to the lifestyle associated with mining. The raised risk of circulatory diseases does not seem to be related to radon or arsenic exposure; its causes are unclear. The use of multiple follow up methods was found to be mortality in the cohort.

• MeSH
• analýza přežití MeSH
• arsen škodlivé účinky   MeSH
• časové faktory MeSH
• dospělí MeSH
• hornictví * MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• následné studie MeSH
• nemoci z povolání mortalita   MeSH
• Poissonovo rozdělení MeSH
• pracovní expozice škodlivé účinky   MeSH
• příčina smrti MeSH
• radon škodlivé účinky   MeSH
• rizikové faktory MeSH
• senioři MeSH
• uran * škodlivé účinky   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Československo MeSH
• Názvy látek
• arsen MeSH
• radon MeSH
• uran * MeSH

Recent data from deep uranium mines in Czechoslovakia indicated that mines are exposed to other mutagenic factors in addition to radon daughter products. Mycotoxins were identified as a possible source of mutagens in these mines. Mycotoxins were examined in 38 samples from mines and in throat swabs taken from 116 miners and 78 controls. The following mycotoxins were identified from mines samples: aflatoxins B1 and G1, citrinin, citreoviridin, mycophenolic acid, and sterigmatocystin. Some mold strains isolated from mines and throat swabs were investigated for mutagenic activity by the SOS chromotest and Salmonella assay with strains TA100 and TA98. Mutagenicity was observed, especially with metabolic activation in vitro. These data suggest that mycotoxins produced by molds in uranium mines are a new genotoxic factor for uranium miners.

• MeSH
• dospělí MeSH
• hornictví * MeSH
• lidé MeSH
• monitorování životního prostředí * MeSH
• mutageny * MeSH
• uran * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Československo MeSH
• Názvy látek
• mutageny * MeSH
• uran * MeSH

Recent data from deep uranium mines in Czechoslovakia indicated that in addition to radon daughter products, miners are also exposed to chemical mutagens. Mycotoxins were identified as a possible source of mutagenicity present in the mines. Various methods of biomonitoring were used to examine three groups of miners from different uranium mines. Cytogenetic analysis of peripheral lymphocytes, unscheduled DNA synthesis (UDS) in lymphocytes, and lipid peroxidation (LPO) in both plasma and lymphocytes were studied on 66 exposed miners and 56 controls. Throat swabs were taken from 116 miners and 78 controls. Significantly increased numbers of aberrant cells were found in all groups of miners, as well as decreased UDS values in lymphocytes and increased LPO plasma levels in comparison to controls. Molds were detected in throat swabs from 27% of miners, and 58% of these molds were embryotoxic. Only 5% of the control samples contained molds and none of them was embryotoxic. The following mycotoxins were isolated from miners' throat swab samples: rugulosin, sterigmatocystin, mycophenolic acid, brevianamid A, citreoviridin, citrinin, penicilic acid, and secalonic acid. These data suggest that mycotoxins are a genotoxic factor affecting uranium miners.

• MeSH
• chromozomální aberace MeSH
• DNA biosyntéza   MeSH
• dospělí MeSH
• hornictví * MeSH
• lidé MeSH
• monitorování životního prostředí MeSH
• mutace * MeSH
• mykotoxiny škodlivé účinky   MeSH
• nádory plic etiologie   MeSH
• nemoci z povolání etiologie   MeSH
• peroxidace lipidů MeSH
• pracovní expozice MeSH
• uran * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Československo MeSH
• Názvy látek
• DNA MeSH
• mykotoxiny MeSH
• uran * MeSH