[Effective dose rate of radon gas in Jooshan hot spring of Kerman Province]

Human beings are constantly exposed to different radiations that have always been recognized as a health hazard. Radon-222 and its daughter products are major sources of natural radiations and a significant total inhalation dose is related to them. Hence, the measurement of radon activity in the environment has gained an increasing importance. In this study, with the measurement of radon concentration, the indoor radon activity level and radon effective dose rate in Jooshan hot spring were determined. Concentration of radon gas inside the pool of Jooshan hot spring was measured using the active detector Rad7 type and the annual effective dose was estimated for individuals inhaling the indoor air of this pool for a specified period of time. Concentration of indoor air radon gas was 98.3 +/- 4.9 Bq/m3 and for a person staying in the pool twice a week and each time for two hours, the annual effective dose rate, due to the inhalation of radon, equals to 0.06 +/- 0.003 mSv/y. Comparison of the obtained effective dose with the standards of Environmental protection Agency and Health physics Society, it can be concluded that for individuals that normally use Jooshan hot spring pool, the resulted dose is in the recommended range

study on radon and thoron progeny levels in dwellings in South India

Decay products of radon and thoron present in indoor environment are the most important sources of radiation from natural sources which affect human beings, since general public spend at lest 80% of their time in indoor. Air samples were collected for measuring the concentration of radon and thoron daughter products from various indoor environments during four different seasons of the year from the Gudalore taluk of Nilgiri Biosphere using high volume air sampler. The concentration of decay products of radon and thoron were estimated using an alpha counter. Studies have revealed that the annual average potential alpha energy concentrations of radon and thoron progeny in dwellings of Gudalore were recorded as 3.54 and 2.65 mWL respectively. It was also observed that the potential alpha energy concentration [PAEC] values for radon progeny undergo dramatic change with the change of season perhaps due to different aerosol contents in the air. The maximum [222]Rn [3.93 mWL] and 220Rn [3.10 mWL] progeny concentrations were observed during winter months and the minimum values [[222]Rn 3.14 mWL and [220]Rn 2.20 mWL] were observed during summer. Studies have shown that the dwelling with mud wall registered high value of radon and thoron progenies [5.49 mWL and 3.88 mWL]. While low values were observed in dwellings with vinyl floor. High concentrations of radon and thoron progeny were observed between 3.00 to 5.00 Hrs, while low values were observed at 14.00 hrs. Studies suggest that radiation emission from radon and thoron daughter in the study area were remained well below the recommended level

Characteristics of Occupational Lung Cancer from 1999 to 2005 / 대한산업의학회지

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.

Environmental monitoring of radon, thoron and their progeny in some dwellings of northern Haryana (India).

The problem of randon is an important global problem of radiation hygiene concerning the world population. Radon and its progeny are the major contributors in the radiation dose received by general population of the world. Keeping this in mind, the environmental monitoring of radon, thoron and their progeny in some dwellings of northern part of Haryana state of India has been carried out. The radon thoron twin dosimeter cups were used for the study. Three pieces of LR-115 solid-state nuclear track detectors were fixed in the dosimeters and were suspended in the dwellings for three months during a season. The first detector indicated radon, thoron and progeny concentration, the second showed radon and thoron concentration, while the third detected only the radon concentration. The aim of study was to carry out possible health risk assessment in the dwellings under consideration. During summer season, the radon concentration in northern region of Haryana varied from 66-97 Bq m(-3), while the thoron concentration in the same dwellings varied from 27-65 Bq m(-3). During winter season, radon concentration in northern region of Haryana varied from 73-104 Bq m(-3) with an average of 88 + 7 Bq m(-3), while the thoron concentration in the same dwellings varied from 35-69 Bq m(-3) with an average of 55 +/- 8 Bq m(-3). The radon-thoron progeny levels and annual doses received by the inhabitants in the dwellings under study have also been calculated.

p16 and MGMT gene methylation in sputum cells of uranium workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>91 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).</p><p><b>RESULTS</b>There 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).</p><p><b>CONCLUSION</b>The methylation of p16 and MGMT gene is related to the accumulate exposure dosage of the radon daughters.</p>

Variability of radon concentrations in different compartments of dwellings in Egypt

Inhalation of indoor radon has been recognized as one of the health hazards. Building materials, natural gas and underground-derived water supply are considered the major sources of indoor radon and its daughters. In this work a set of radon measurements was carried out, using CR-39 solid state nuclear track detector, in different compartments of dwellings in Cairo built of the same type of building materials. The results showed that the radon concentrations and exhalation rates in these houses varied from 47.94 to 84.32 Bqm-3 and 2.59 to 4.04 mBqm-2 h-2 respectively. The mean values of radon concentrations in living rooms, bedrooms, bathrooms and kitchens were 50.98 +/- 1.94, 53.18 +/- 3.69, 79.36 +/- 2.96, and 81.29 +/- 1.93 Bqm-3, respectively. The mean values of exhalation rates were 2.68 +/- 0.11, 2.79 +/- 0.19, 4.01 +/- 0.18, and 4.22 +/- 0.12 mBqm-2 h-1, respectively. This data show that bathrooms and kitchens have significantly higher radon concentrations and exhalation rates compared with other compartments and the outdoor levels

Diurnal and monthly variation of indoor radon and thoron progeny concentrations at a hillside place of northern India.

The natural radioactivity levels all over the world can create health problems due to the inhalation of radioactive aerosols. Radon and thoron progeny content of indoor air have major contribution to natural radiation dose. In the present study, simultaneous indoor measurements of radon and thoron progeny concentrations have been carried out over a period of four months at a low activity hilly area of northern Punjab, India to see their diurnal and monthly variations. The method used for this purpose is based on the defined solid angle absolute beta counting of radioactive aerosols sampled on a filter. The average values of equilibrium equivalent radon and thoron concentrations were 5.20 Bq m(-3) and 0.235 Bq m(-3), respectively, over the period August to November 2003. Both, EECRn and EECTh show a negative correlation with temperature.

Modelo dosimétrico para o radônio e filhos / Dosimetric model for radon and short-lived daughters

Desenvolveu-se neste trabalho um modelo dosimétrico para radônio e filhos de meia vida curta a partir do novo modelo do trato respiratório da publicação 66 da ICRP, em conjunto com seus novos modelos sistêmicos. Propos-se um modelo biocinético sistêmico tomando-se como base o modelo para gases inertes de Peterman e Perkins, de acordo com o formalismo proposto pelos novos modelos da ICRP. Validou-se o modelo através da reprodução dos dados experimentais para ûüüXe em humanos publicados por estes autores. Estendeu-se este modelo ao radônio, mostrando que o uso do modelo do trato respiratório da Publicação 66 da ICRP prediz uma taxa de dose superior aquela obtida pelos diferentes autores. Conclui-se então, que a dose devida à inalação dos filhos de meia-vida curta. A metodologia utilizada dispõe ainda de previsão para correlacionar a incorporação de radionuclídeos com a atividade em órgãos e excretas, considerando a diferenciação do comportamento metabólico dos produtos de decaimento e seu antecessor, nas cadeias radioativas. Estimou-se as doses devidas a inalação de filhos de meia-vida curta de radônio utilizando-se o modelo do trato respiratório da Publicação 66 da ICRP e os modelos biocinéticos novos, propostos nas Publicações 67 e 69. Comparou-se os resultados utilizando-se o modelo biocinético proposto. Os cálculos utilizando-se os modelos propostos pela ICRP reproduziram os fatores de conversão de dose efetiva recomendada pela Publicação 65 da ICRP. Os resultados gerados pelo modelo proposto são coerentes com as doses médias no pulmão, calculadas por Jacobi e Eisfeld e com os valores publicados pela ICRP. Recomenda-se então, a utilização de coeficientes de dose equivalente e coeficientes de dose efetiva comprometidas em Sv/Bq, obtidos a partir de modelos biocinéticos, ao invés dos fatores de conversão em Sv/WLM encontrados na literatura e usados nos programas de monitoração destes produtos. O uso destes coeficientes tem as seguintes vantagens: (a) leva em consideração a taxa de respiração, (b) o tamanho do particulado e as condições de exposição, (c) fornecem bases para comparação com outros tipos de radiação que o uso do WLM não permite, podendo-se extrapolar a outras faixas etárias da população