OBJECTIVETo study the methylation of O-6-methylguanine-DNA methyltransferase (MGMT) and p16 gene in the sputum cells of radon-exposed population. To provide the experimental base for finding the molecular biomarker of the high risk population of the radon-induced lung cancer.

METHODS91 radon-exposed workers were divided into 4 groups, high dosage group (> 120 WLM), middle dosage group (between 60 and 120 WLM), low dosage group (between 30 and 60 WLB) and lower dosage group (between 2 and 30 WLM) according to the accumulated exposure dosage of the radon daughters. The abnormal methylation of p16 and MGMT gene in the sputum cells of the population in the four groups was detected with the methylation specific PCR (MSP).

RESULTSThere was significantly upward trend for the p16 gene methylation rate (0.00%-20.00%), the MGMT gene methylation rate (0.00%-28.00%) and the total methylation rate (0.00%-40.00%) with the increase of the accumulated exposure dosage of the radon daughters (P < 0.01).

CONCLUSIONThe methylation of p16 and MGMT gene is related to the accumulate exposure dosage of the radon daughters.

Carcinogens, Environmental ; adverse effects ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; metabolism ; DNA Methylation ; Dose-Response Relationship, Radiation ; Humans ; Male ; O(6)-Methylguanine-DNA Methyltransferase ; genetics ; metabolism ; Occupational Exposure ; Radon ; adverse effects ; Radon Daughters ; adverse effects ; Sputum ; metabolism

OBJECTIVES: The aim of this study was to investigate the characteristics of occupational lung cancer. METHODS: We analyzed the characteristics of 53 occupational lung cancer cases among 128 lung cancer cases applied for industrial accident compensation insurance benefits and referred for the decision of work-relatedness between 1999 and 2005. Statistical analysis was conducted using the Chi-square test on 128 lung cancer cases. RESULTS: The age of diagnosis, smoking history, and cell type of lung cancer cases were not significantly different between 53 cases of occupational lung cancer and 75 cases of non-occupational lung cancer (p>.05). Here is a list of occupational lung cancer case numbers associated with certain carcinogens were: 33(62.3%) cases with asbestos, 23(43.4%) cases with polycyclic aromatic hydro carbon (PAH), 17 cases(32.1%) with chromium VI (Oxidation state), 14 cases(26.4%) with crystalline silica, 12 cases (22.6%) with nickel compounds, 2 cases(3.8%) with radon daughters, and 1 case(1.9%) with arsenic. Eighteen cases(34.0%) of occupational lung cancer had exposures to a single carcinogen, and 35 cases (66.0%) had exposures to more than 2 carcinogens. Job types associated with occupational lung cancer cases were: 16 cases(30.2%) with maintenance, 13 cases(24.5%) with welding; 6 cases(11.3%) with grinding; 4 cases(7.5%) with foundry; 3 cases(5.7%) with driving, casting, and painting' and 14 cases (26.4%) with 'other'. CONCLUSIONS: This study identified the characteristics of occupational lung cancer through the analysis of the age of diagnosis, smoking history, cell type, job, and carcinogen. There is no difference between occupational lung cancer and non-occupational lung cancer except exposure to the carcinogens. these results indicate that past exposure to occupational carcinogens remains an important determinant of occupational lung cancer occurrence.
Accidents, Occupational ; Arsenic ; Asbestos ; Carbon ; Carcinogens ; Chromium ; Compensation and Redress ; Crystallins ; Insurance Benefits ; Lung ; Lung Neoplasms ; Nickel ; Occupational Health ; Radon Daughters ; Silicon Dioxide ; Smoke ; Smoking

Since the Compton camera was fi rst introduced, various types of conical Radon transforms have been examined. Here, we derive the inversion formula for the conical Radon transform, where the cone of integration moves along a curve in three-dimensional space such as a helix. Along this three-dimensional curve, a detailed inversion formula for helical movement will be treated for Compton imaging in this paper. The inversion formula includes Hilbert transform and Radon transform. For the inversion of Compton imaging with helical movement, it is necessary to invert Hilbert transform with respect to the inner product between the vertex and the central axis of the cone of the Compton camera. However, the inner product function is not monotone. Thus, we should replace the Hilbert transform by the Riemann–Stieltjes integral over a certain monotone function related with the inner product function. We represent the Riemann–Stieltjes integral as a conventional Riemann integral over a countable union of disjoint intervals, whose end points can be computed using the Newton method. For the inversion of Radon transform, three dimensional fi ltered backprojection is used. For the numerical implementation, we analytically compute the Hilbert transform and Radon transform of the characteristic function of fi nite balls. Numerical test is given, when the density function is given by a characteristic function of a ball or three overlapping balls.
Methods ; Radon

No abstract available.
Lung Neoplasms* ; Lung* ; Radon*

No abstract available.
Korea* ; Lung Neoplasms* ; Lung* ; Radon*

No abstract available.
Korea* ; Lung Neoplasms* ; Lung* ; Radon*

Radiation from natural sources is one of causes of the environmental diseases. Radon is the leading environmental cause of lung cancer next to smoking. To investigate the relationship between indoor radon concentrations and lung cancer, researchers must be able to estimate an individual’s cumulative level of indoor radon exposure and to do so, one must first be able to assess indoor radon concentrations. In this article, we outline factors affecting indoor radon concentrations and review related mathematical models based on the mass balance equation and the differential equations. Furthermore, we suggest the necessities of applying time-dependent functions for indoor radon concentrations and developing stochastic models.
Lung Neoplasms ; Models, Theoretical* ; Radon* ; Smoke ; Smoking

PURPOSE: Exposure to indoor radon is associated with lung cancer. This study aimed to estimate the number of lung cancer deaths attributable to indoor radon exposure, its burden of disease, and the effects of radon mitigation in Korea in 2010. MATERIALS AND METHODS: Lung cancer deaths due to indoor radon exposure were estimated using exposure-response relations reported in previous studies. Years of life lost (YLLs) were calculated to quantify disease burden in relation to premature deaths. Mitigation effects were examined under scenarios in which all homes with indoor radon concentrations above a specified level were remediated below the level. RESULTS: The estimated number of lung cancer deaths attributable to indoor radon exposure ranged from 1946 to 3863, accounting for 12.5–24.7% of 15623 total lung cancer deaths in 2010. YLLs due to premature deaths were estimated at 43140–101855 years (90–212 years per 100000 population). If all homes with radon levels above 148 Bq/m3 are effectively remediated, 502–732 lung cancer deaths and 10972–18479 YLLs could be prevented. CONCLUSION: These findings suggest that indoor radon exposure contributes considerably to lung cancer, and that reducing indoor radon concentration would be helpful for decreasing the disease burden from lung cancer deaths.
Korea ; Lung Neoplasms* ; Lung* ; Mortality, Premature ; Radon*

Eleven cohorts of miners occupationally exposed to relatively high concentrations of radon showed a statistically significantly high risk of lung cancer, while three cohorts from the general population showed a relatively low concentration, but the results were not statistically significant. However, the risk of lung cancer tended to increase with increased radon exposure. The risk is likely to have been underestimated due to low statistical power. Therefore, additional well-designed studies on the risk of lung cancer in nonsmokers in the general population with relatively low concentrations of radon exposure are needed in the future. In addition, country-specific preventive policies are needed in order to actively reduce radon exposure and lung cancer incidence in nonsmokers.
Cohort Studies* ; Incidence ; Lung Neoplasms* ; Lung* ; Miners ; Occupations ; Radon*

Breath Tests ; Humans ; Mining ; Pneumoconiosis ; diagnosis ; Radon ; analysis