Investigation and analysis of indoor radon concentration of urban residents in Shiyan, China / 中国辐射卫生

@#<b>Objective</b> To monitor the indoor radon concentration of urban residents in Shiyan, China, and to analyze the related influencing factors. <b>Methods</b> From April to July, 2019, RSKS standard detectors were used to measure the indoor radon concentration of 125 households in Shiyan, and the results were analyzed. <b>Results</b> The indoor radon concentration of residents in Shiyan showed a skewed distribution, ranging from 13.8 to 145 Bq/m³, and <i>M</i> (<i>P</i>₂₅,<i>P</i>₇₅) was 38.3 (29.0,62.0) Bq/m³. The estimated annual effective dose of radon and radon daughters from inhalation was 0.52-5.50 mSv, and <i>M</i> (<i>P</i>₂₅,<i>P</i>₇₅) was 1.45 (1.10, 2.36) mSv, which was consistent with literature. Building structure (<i>H</i> = 14.10, <i>P</i> < 0.001), floor (<i>H</i> = 24.41, <i>P</i> < 0.001), and geographical region (<i>H</i> = 8.963, <i>P</i> < 0.05) were influencing factors of indoor radon concentration, and the differences were significant. <b>Conclusion</b> The indoor radon concentration of urban residents in Shiyan is lower than the national standard limit. However, in daily life, it is still necessary to take appropriate measures to reduce the concentration of indoor radon as much as possible.

Indoor radon concentration and its changing trend in northeastern China / 中国辐射卫生

@#<b>Objective</b> To investigate the indoor radon concentration and its changing trend in northeastern China. <b>Methods</b> We measured indoor radon levels cumulatively for over three months by solid state nuclear track detection in a total of 261 houses in multi-story or high-rise buildings in Shenyang, Changchun, Harbin, Heihe, and Yichun in northeastern China. The measurement lasted one year in Changchun for seasonal changes. <b>Results</b> The average indoor radon concentration in the five cities was 88 Bq/m³, ranging from 12 to 558 Bq/m³. The indoor radon concentrations were ≤ 100 Bq/m³ in 75.1% of the houses, and ≤ 300 Bq/m³ in 97.7% of the houses. The indoor radon concentration increased with the age of buildings. The indoor radon concentration was highest in winter, and it was higher in summer than in autumn and spring. <b>Conclusion</b> The indoor radon concentration in northeastern China increased compared with the data of 1980s and 1990s. It is highest in the winter heating season, and higher in summer than in spring and autumn. Indoor radon exposure deserves attention.

Risk estimation for lung cancer caused by indoor radon exposure in China based on EPA/BEIR-VI model / 中华放射医学与防护杂志

Objective:To estimate the attribution share of residents′lung cancer caused by indoor Radon.Methods:Based on the 2015 lung cancer mortality, all-cause mortality from China together with nationally representative smoking rate and the average indoor radon concentration of 30 Bq/m 3, the relatively authoritative and applicable EPA/BEIR-VI risk model was used to predict the lung cancer mortality caused by indoor radon exposure. Results:The excess relative risk (ERR) of indoor radon-related lung cancer mortality among the male non-smokers is higher than that of smokers. For the age-group above 50, the male smokers and male non-smokers have the highest ERR values, which were 0.511 and 0.230, respectively. Assuming the exposure incurred starting at age 0 with the same radon concentration, the lifetime risk of men and women non-smokers is higher than that of the smokers of the same gender. The higher the radon concentration, the higher the lifetime risk of lung cancer. Assuming that the radon concentration level in China is 30 Bq/m 3, the number of deaths from indoor radon-related lung cancer in 2015 is about 55 512. According to this, about 6.62% of lung cancers are caused by indoor radon exposure. If we assume that radon concentration levels are 40 Bq/m 3and 70 Bq/m 3 in China, approximately 8.82% and 15.38% of lung cancer deaths can be attributed to indoor radon exposure. Conclusions:Indoor radon exposure is an important environmental factor that causes Chinese residential lung cancer. Effective measures should be taken to prevent and control the increasing indoor radon levels. In order to accurately assess risk of lung cancer morality caused by indoor radon, more detailed data such as the indoor radon level in China are needed.

Indoor Radon and Lung Cancer: Estimation of Attributable Risk, Disease Burden, and Effects of Mitigation

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.

Measurement and modeling of indoor radon concentrations in residential buildings

Radon, the primary constituent of natural radiation, is the second leading environmental cause of lung cancer after smoking. To confirm a relationship between indoor radon exposure and lung cancer, estimating cumulative levels of exposure to indoor radon for an individual or population is necessary. This study sought to develop a model for estimate indoor radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking. In order to develop a model, indoor radon concentrations were measured at 196 ground floor residences using passive alpha-track detectors between January and April 2016. The arithmetic mean (AM) and geometric mean (GM) means of indoor radon concentrations were 117.86±72.03 and 95.13±2.02 Bq/m³, respectively. Questionnaires were administered to assess the characteristics of each residence, the environment around the measuring equipment, and lifestyles of the residents. Also, national data on indoor radon concentrations at 7643 detached houses for 2011-2014 were reviewed to determine radon concentrations in the soil, and meteorological data on temperature and wind speed were utilized to approximate ventilation rates. The estimated ventilation rates and radon exhalation rates from the soil varied from 0.18 to 0.98/hr (AM, 0.59±0.17/hr) and 326.33 to 1392.77 Bq/m²/hr (AM, 777.45±257.39; GM, 735.67±1.40 Bq/m²/hr), respectively. With these results, the developed model was applied to estimate indoor radon concentrations for 157 residences (80% of all 196 residences), which were randomly sampled. The results were in better agreement for Gyeonggi and Seoul than for other regions of Korea. Overall, the actual and estimated radon concentrations were in better agreement, except for a few low-concentration residences.

Measurement and modeling of indoor radon concentrations in residential buildings

Radon, the primary constituent of natural radiation, is the second leading environmental cause of lung cancer after smoking. To confirm a relationship between indoor radon exposure and lung cancer, estimating cumulative levels of exposure to indoor radon for an individual or population is necessary. This study sought to develop a model for estimate indoor radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking. In order to develop a model, indoor radon concentrations were measured at 196 ground floor residences using passive alpha-track detectors between January and April 2016. The arithmetic mean (AM) and geometric mean (GM) means of indoor radon concentrations were 117.86±72.03 and 95.13±2.02 Bq/m³, respectively. Questionnaires were administered to assess the characteristics of each residence, the environment around the measuring equipment, and lifestyles of the residents. Also, national data on indoor radon concentrations at 7643 detached houses for 2011-2014 were reviewed to determine radon concentrations in the soil, and meteorological data on temperature and wind speed were utilized to approximate ventilation rates. The estimated ventilation rates and radon exhalation rates from the soil varied from 0.18 to 0.98/hr (AM, 0.59±0.17/hr) and 326.33 to 1392.77 Bq/m²/hr (AM, 777.45±257.39; GM, 735.67±1.40 Bq/m²/hr), respectively. With these results, the developed model was applied to estimate indoor radon concentrations for 157 residences (80% of all 196 residences), which were randomly sampled. The results were in better agreement for Gyeonggi and Seoul than for other regions of Korea. Overall, the actual and estimated radon concentrations were in better agreement, except for a few low-concentration residences.

INDOOR RADON SURVEY IN NEPAL USING PASSIVE TECHNIQUE SOLID STATE NUCLEAR TRACK DETECTOR

Context: It has been proved from many epidemiological studies that the inhalation of the radioactive, inert gas radon (222Rn) is the main cause of lungs cancer after smoking. Objective: The survey was conducted to estimate the indoor radon concentration, the annual effective dose rate and the annual dose equivalent rate to the lung. Material and Methods: Altogether 50 dwellings were chosen randomly at 5 different districts of Nepal. The dosimetric measurements were carried out over a period of 3 months using time-integrated passive radon detectors, CR-39 based on type II Solid State Nuclear Track Detector (SSNTD) technique. The type of houses was concrete with plastered walls and mud house. Results: The minimum concentration of radon in the study areas was found to be <20Bq.m-3 and the maximum concentration was 110±20Bq.m-3. Also the corresponding values of annual effective dose and annual equivalent dose to the lung respectively varied from <0.60 to 3.30mSv.y-1 and 0.16×10-7 to 0.88×10-7 Sv.y-1. The uncertainty was measured at 95% confidence level. Conclusion: The indoor radon concentration varies considerably with the ventilation condition, lifestyle of the people, construction of the dwellings and climate of the areas. The measurements show that the radon concentrations were found to be well below the reference levels of ICRP.

Indoor ²²²Rn levels and effective dose estimation of academic staff in İzmir, Turkey / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building.</p><p><b>METHODS</b>Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylül University for two surveys of about 1 month duration respectively using the SSNTD (Solid State Nuclear Track Detectors) method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building: classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon.</p><p><b>RESULTS</b>The arithmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose.</p><p><b>CONCLUSION</b>Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.</p>

Indoor radon level and distribution characteristic in Zhuhai city / 中华放射医学与防护杂志

Objective To analyze the indoor radon level and distribution characteristic in different geological background by studying the indoor radon level in three typical areas in Zhuhai City.Methods The region of investigation includes three districts:granite area in Zhuhai District,granite area in Doumen District and the Quaternary sedimentary area in Doumen District.Activated charcoal adsorption method was used to measure the indoor radon concentrations.In some sampling sites,solid state nuclear track detectors were used at the same time for the indoor radon measurement.Results The average indoor radon level included 80 buildings was (66.0 ± 49.8) Bq/m3 using activated charcoal adsorption method and the maximum value was 1078.5 Bq/m3.The results of 23 sampling sites show that the average indoor radon level using solid state nuclear track detectors was (88.8 ± 49.1) Bq/m3,and (69.5 ± 37.7) Bq/m3 by activated charcoal adsorption method.The indoor radon concentration was (73.6 ± 61.0),(87.5 ± 58.3) and (48.6 ± 22.6) Bq/m3 in granite area in Zhuhai District,granite area in Doumen District and the Quaternary sedimentary area in Doumen District,respectively.Conclusions The surface lithology of an area has a certain impact on the indoor radon level.The indoor radon level in granite area in Zhuhai District and Doumen District is apparently higher than that in the Quaternary sedimentary area in Doumen District.The study of indoor radon level and distribution characteristic should be discussed in combination with geological background of area.

A survey of indoor radon in rayong province.

A study of indoor was carried out on 615 different building in Rayong Province, Thailand, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concentrations from 4.00 to 74.15 becquerels/cubic metre (13.23+8.97 Bq.M-3). Although the levels of radon encountered were well below the safety threshold of 148 Bq.M-3 established by the U.S. Environmental Protection Agency, there were statistically significant difference between some districts. With regard to the type, age and ventilation status of the buildings, and the occupant’s practice of smoking indoor, the findings of this investigation do not warrant a conclusion that would support the notion of these factors contributing to, or being mutually associated with, indoor gaseous concentrations of radon.

A survey of indoor radon in samutprakarn province.

A study of indoor radon was carried out on 1,024 different buildings in Samutprakarn province, Thailand, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concentration from 4.00 to 47.51 Bequerels/cubic metre (7.47+4.69 Bq.m-3). Although the levels of radon encountered were well below the safety threshold of 148 Bq.m-3 established by the U.S. Environmental Protection Agency, there were statistically significant differences between some districts. With regard to the type, age and ventilation status of the buildings, and the occupants’ practice of smoking indoors, the findings of this investigation do not warrant a conclusion that would support the notion of these factors contributing to, or being mutually associated with, indoor gaseous concentrations of radon.

A survey of indoor radon in lampang province.

During the months of December 1997 and January 1998, a study of indoor radon was carried out on 786 different buildings in 13 districts of Lampang Province in northern Thailand, using the charcoal canister method. The survey revealed the presence of radon gas inside all buildings investigated, varying in concentration from 4.00 to 176.73 becquerels/cubic metre (32.41+21.14 Bq.m-3); an elevated concentration over 150 Bq.m-3 was encountered in only one house in Muangpan district. Although the other measurements did not reveal indoor radon levels exceeding the safety threshold, the prevalence of high levels within normal range was detected among the building in the adjoining four districts (Amphur Muangpan, Amphur Hangchat, Amphur Jaehom and Amphur Koa-ka). With regard to the type, age and ventilation status of the buildings, and the practice of smoking indoors, the findings of this investigation do not conclusively support the notion of their contributing to, or being mutually associated with, indoor gaseous concentrations of radon.

Indoor radon in nakornpathom province, Thailand.

During the months of July and August 1997, a survey to determine the existence of indoor radon was carried out, using an activated charcoal technique, in 474 different buildings in Nakornpathom Province. The presence of radon gas was encountered inside all the buildings investigated, varying in concentration from 4.00 to 86.40 Bq.m-3 (13.45 + 9.23 Bq.m-3). With regard to the type, age and ventilation status of the buildings, and the practice of smoking indoors, the findings do not conclusively support the notion of their contributing to, or mutually associated with, indoor gaseous concentrations of radon.

A survey of indoor radon in songkla province.

A study of indoor radon was carried out on 1,052 different buildings in Songkla Province, Thai-land, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concen-tration from 2.14 to 86.10 Bequerels/cubic metre (16.15 + 11.97 Bq.m-3). Although the levels of radon encoun-tered were well below the safety threshold of 148 Bq.m-3 established by the U.S. Environmental Protection Agency, a trend was detected suggesting that high levels within the normal range are prevalent in certain areas of the province. The phenomenon will be investigated in the next setting. With regard to the type, age and ventilation status of the buildings, and the practice of smoking indoors, the findings of this investigation do not conclusively support the notion of their contributing to, or being mutually associated with, indoor gaseous concentrations of radon.

Indoor radon in a glass building.

Measurement of radon was carried out on seven different floors of a 32-storey glass-faced building. It revealed the presence of relatively comparable amounts of radon on every one of the floors investigated; however, the concentrations (4.00-14.53 Bq/m3) did not exceed the safety threshold. Based on the result of a previous investigation showing significant concentrations of radon in concrete buildings, it is imputed from the finding of the present study that the type of glass used as a building material in this case was unlikely to be an additional source of radon.

A survey of indoor radon in khon kaen province.

A study of indoor radon was carried out on 319 different buildings in five districts (Amphurs Muang, Phuwiang, Khou-suankwan, ubolrat and Nampong) of Khonkaen Province in northeastern Thailand, using an activated charcoal canister for gaseous collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, with overall concentrations being 15.33 + 22.13 bequerels/cubic metre and the prevalence rate of elevated values being 0.94 percent. The prevalence f higher indoor radon concentrations in Amphur Phuwiang (32.18+ 44.05) Bq.m-3) differs statistically from the concentrations encountered in the four other districts. In considering the age of the buildings and the type of building materials, the differences in indoor radon concentrations were not statistically significant. Indoor cigarette smoking and the inappropriate ventilation of the buildings appeared to relate to the higher radon concentrations.

A survey of indoor radon in phuket province.

A study of indoor radon was carried out on 271 different buildings in the districts (Amphurs Thalang, Muang and Kratoo) of Phuket Province in Southern Thailand, using an activated charcoal canister for gaseous collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, varying in concentration from 4 to 82.50 Bequerels/cubic metre (14.09 + 11.48 Bq.m-3), i.e., well below the threshold limit of 148 Bq.m-3 established by the American Environmental Protection Agency. The results of measurement of radon concentrations in Amphur Kratoo (22.27 + 18.93 Bq.m-3), Amphur Thalang (14.45 + 10.11 Bq.m-3), and Amphur Muang (10.25 + 5.95 Bq.m-3) showed a marked statistically significant difference (p < 0.005). In considering the age of the buildings (less than 1 year, 1-5 years and over 5 years old), types of building materials (concrete, wood, zinc sheeting and glass) and the apprarent difference of ventilation, the differences in indoor radon concentrations were not statistically significant (P > 0.05). Indoor cigarette smoking did not affect indoor radon concentrations (p = 0.072).

A survey of indoor radon in kanchanaburi province.

A study of indoor radon was carried out on 287 different buildings in four districts (Amphur Muang, A. Tha Muang, A. Tha Maka and A. Phanomthuan) of Kanchanaburi Province, Thailand, using an activated charcoal canister for sample collection and a gamma spectrometer for analysis of the samples. The survey revealed the presence of radon gas inside all the buildings investigated, with overall concentrations being 125.38 + 145.43 Bq.m-3 and the prevalence rate of elevated values being 31.70 percent. Concentrations of 131.14 + 116.36 Bq.m-3 with a 32.39 percent prevalence rate were obtained in Amphur Muang (71 buildings) ; 98.31 + 91.36 Bq.m-3 with a 22.41 percent prevalence rate in Amphur Tha Muang (58 buildings) ; 160.35 + 95.30 Bq.m-3 with a 56.66 percent prevalence rate in Amphur Tha Maka (60 buildings) ; 115.82 + 202.10 Bq.m-3 with a 21.24 percent prevalence rate in Amphur Phanomthuan (98 buildings). The higher prevalence at Amphur Tha Maka differs statistically from the prevalence encountered in the three other districts. In considering buildings constructed less than five years previously and those five or more years old, there were no statistically significant differences with regard to both the radon concentrations and the prevalence rate of elevated concentrations. There was evidence suggesting that sources of indoor radon are both the soil and construction materials. Buildings with good ventilation (e.g., houses built on high posts, and those with doors and windows frequently opened) showed somewhat less accumulation of indoor gas, without statistically significant difference (P>0.05).

Indoor radon and lung cancer.

Fifty-four hourses, mostly in Bangkok and Nonthaburi, where 54 lung cancer patients had lived for same time were selected for investigating the presence of indoor radon by the charcoal canister method. In only four of these houses were radon level higher than the normal threshold level of 150 Bq.m (i.e. 153, 160, 172 and 283 Bq.m). Thus, the prevalence of elevated radon concentrations was a mere 7.40 percent in contrast with 22.16 percent found in the general survey. Although this finding would apparently suggest a negative relationship between indoor radon concentrations and lung cancer, it is possible that those patients had been exposed earlier to high radon concentrations, perhaps when the buildings were still new. It should be remembered also that exposure to even low radon concentrations dose not rule out the potential hazard of this radioactive gas as a cause of lung cancer. Most houses in this study (92.60%) were constructed of concrete and more than 5 years old. Therefore, it is not surprising to encounter such low radon levels, since rates are usually higher in newer buildings.