• Journal of Biomedical Engineering Research
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• v.39 no.6
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• pp.243-249
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• 2018

The indoor radon concentration was measured in the lecture room of the university and the radon concentration was converted to the amount related to the radon exposure using the dose conversion convention and compared with the reference levels for the radon concentration control. The effect of indoor radon inhalation was evaluated by estimating the life effective dose and the risk of exposure. To measure the radon concentration, measurements were made with a radon meter and a dedicated analysis Capture Ver. 5.5 program in a university lecture room from January to February 2018. The radon concentration measurement was carried out for 5 consecutive hours for 24 hours after keeping the airtight condition for 12 hours before the measurement. Radon exposure risk was calculated using the radon dose and dose conversion factor. Indoor radon concentration, radon exposure risk, and annual effective dose were found within the 95% confidence interval as the minimum and maximum boundary ranges. The radon concentration in the lecture room was $43.1-79.1Bq/m^3$, and the maximum boundary range within the 95% confidence interval was $77.7Bq/m^3$. The annual effective dose was estimated to be 0.20-0.36 mSv/y (mean 0.28 mSv/y). The life-time effective dose was estimated to be 0.66-1.18 mSv (mean $0.93{\pm}0.08mSv$). Life effective doses were estimated to be 0.88-0.99 mSv and radon exposure risk was estimated to be 12.4 out of 10.9 per 100,000. Radon concentration was measured, dose effective dose was evaluated using dose conversion convention, and degree of health hazard by indoor radon exposure was evaluated by predicting radon exposure risk using nominal hazard coefficient. It was concluded that indoor living environment could be applied to other specific exposure situations.

• Journal of Environmental Health Sciences
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• v.42 no.5
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• pp.345-351
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• 2016

Objectives: The objective of this study was to conduct risk assessment using indoor radon concentration and exposure times. Methods: The target facilities were military facilities before and after the application of radon reduction processes and underground commercial facilities in major subway stations in Seoul. Indoor radon concentrations were measured by passive sampler. Results: Radon concentrations in 13 military facilities were initially higher than the guidelines, but the levels were below guidelines after the application of radon reduction processes. Underground shopping mall radon concentrations near subway stations in Seoul satisfied the guidelines. However, indoor radon effective doses after radon reduction processes in some military facilities and those in underground shopping malls belonged to International Commission on Radiological Protection (ICRP) groups needing control management. Conclusion: Indoor radon management requires risk assessment data that takes into account working time (or residence time) in addition to management according to concentration guidelines.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.241-249
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• 2001

A report by the National Research Council in the United States suggested that many lung cancer deaths each year are associated with breathing radon in indoor air. Most of the indoor radon comes directly from soil beneath the basement of foundation. Recently, radon released from groundwater is found to contribute to the total inhalation risk from indoor air. This study presents the assessment of a exposure to radon released from the groundwater into indoor air. At first, a 3-compartment model is describe the transfer and distribution if radon released from groundwater in a house through showering, washing clothes, and flushing toilets. The model is used to estimate a daily human exposure through inhalation of such radon for adults based on two sets of exposure scenarios, Finally, a sensitivity analysis is used to identify important parameters. The results obtained from the study would help to increase the understanding of risk assessment issues associated with the indoor radon released from groundwater.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E2
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• pp.43-51
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• 2001

A report by the national research council in the United States suggested that many lung cancer deaths each year be associated with breathing radon in indoor air. Most of the indoor radon comes directly from soil beneath the basement of foundations. Recently, radon released from groundwater is found to contribute to the total inhalation risk from indoor air. This study presents the quantitative assessment of human exposures to radon released from the groundwater into indoor air. At first, a three-compartment model is developed to describe the transfer and distribution of radon released from groundwater in a house through showering, washing clothes, and flushing toilets. Then, to estimate a daily human exposure through inhalation of such radon for an adult. a physiologically-based pharmacokinetic(PBPK) model is developed. The use of a PBPK model for the inhaled radon could provide useful information regarding the distribution of radon among the organs of the human body. Indoor exposure patterns as input to the PBPK model are a more realistic situation associated with indoor radon pollution generated from a three-compartment model describing volatilization of radon from domestic water into household air. Combining the two models for inhaled radon in indoor air can be used to estimate a quantitative human exposure through the inhalation of indoor radon for adults based on two sets of exposure scenarios. The results obtained from the present study would help increase the quantitative understanding of risk assessment issues associated with the indoor radon released from groundwater.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.155-161
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• 2015

Radon is a naturally occurring radioactive gas and a major indoor contribution of exposure to ionizing radiation in dwellings. $^{222}Rn$ is a health hazard gas what is responsible for thousand lung cancer deaths every year. In this study, indoor radon concentrations present in thirty representative houses in Mahallat city, Iran, were determined in order to estimate lung cancer risk associated with residential radon exposure. Long-term passive method, using CR-39, was used to measure the radon concentration. The results showed an association between the age of the dwellings and the indoor radon concentration that was found, in that the concentration of radon tended to increase as the age of the dwelling also increased. The indoor radon concentrations were calculated to be within the range of $23{\pm}2$ to $350{\pm}26Bq{\cdot}m^{-3}$, with an average of $158Bq{\cdot}m^{-3}$. The annual effective dose from inhaled radon and its decay products was calculated between $0.8{\pm}0.1$ and $12.3{\pm}0.9mSv{\cdot}y^{-1}$, with an average of $5.5mSv{\cdot}y^{-1}$. By taking into consideration the EPA recommendation and ICRP statement, the average annual risk of lung cancer from inhaled radon was calculated as 0.09%, 0.06%, 0.01%, and 0.03% for current smokers (CS), those who had ever smoked (ES), never smokers (NS) and the general population, respectively.

• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.79-86
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• 2001

This study presents the quantitative exposure assessment of indoor radon released from groundwater. Most of the Indoor radon comes directly from soil beneath the basement or foundation. Recently, radon in groundwater releases to indoor air whenever the water is used and contributes to the total inhalation risk from indoor air. This study first develops a mathematical model to describe the transfer and distribution of radon released from groundwater in a house. Then, daily human exposures through inhalation or such radon are estimated with the model for an male adult based on two sets of exposure scenarios. The results obtained from the study would help increase the understanding of risk assessment issues associated with the indoor radon released from groundwater.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.382-392
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• 2017

Objectives: The purpose of this study is to obtain basic data on the development of a risk communication model through an investigation of risk perception for radon and identify effective risk communication channels. Methods: A questionnaire was used to evaluate differences in perception level according to respective communication channels. A chi-squared test was used to analyze the difference in pre- and post-risk communication by communication channel. One-way ANOVA was used to analyze the difference in the radon risk perception rate for each communication channel. Results: All of the communication channels resulted in increased radon risk perception, but there was no statistical difference between them in terms of perception (p>0.05). However, based on previous findings that it is effective to use a multi-channel approach, it is considered that communication channels based on duplicate avenues is most appropriate. Conclusions: It is expected that this study will be used as basic data to better understand the formation of public opinion about radon risk and to understand the social reaction to each risk factor.

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1123-1130
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• 2018

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 $148Bq/m^3$ 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.

• Environmental Analysis Health and Toxicology
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• v.16 no.2
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• pp.43-50
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• 2001

A daily newspaper in Korea addressed an controversial issue recently that the concentration of radon measured from the groundwater in Taejon was found out a relatively high level. The cancer risk arising from ingestion of such radon should be derived from calculation of the dose absorbed by the tissues at risk. The study performed by the National Research Council in United States confirmed that the use of a PBPK model for the ingested radon could provide the useful information regarding the distribution of radon among the organs of the body. This study presents an approach for the internal dose assessment of ingested radon for this case. At first, the study develops a PBPK model for ingested radon. However, the important issue is how to simulate a more realistic situation using the model associated with repeated oral doses rather than a single oral dose. The simulations are performed for repeated oral exposures per 8-hour interval using the PBPK model for a male adult. The concentration and cumulative value of radon concentration are calculated and analyzed for lung tissue and adipose group, respectively. The results could be used for the realistic prediction of the internal dose of radon in the human body for repeated oral exposures.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.170-170
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• 2003

An initial study has been conducted with Korea Institute of Geoscience and Mineral resources and National Institute of Environment Research to evaluate the distribution of radon levels and their risk levels of groundwater in Korea. Probability distribution of 616 samples was log-normal one with 1,867pCi/L as arithmetic value, 920pCi/L as median and 40,010pCi/L as maximum during iou. years(1999-2002). In addition, 10% of total samples are in excess of 4,000pCi/L, 20% in excess of 2,700pCi/L, and 30% in excess of 1,700pCi/L, and 15 samples exceeds 10,000pCi/L. Total samples are grouped into 10 areas and 5 rocks unit, and difference of concentrations among areas and rocks are statistically significant(respectively, p<0.0001). The highest area is Daejeon located in ogcheon metamorphic rocks and granitic rocks, and most of all sites with high concentration sites are located in granitic rocks. The lowest area is Jeju located in volcanic rocks. We have estimated excess cancer risks of radon based on these data. To estimate risks, first of all, use patterns of groundwater are categorized with 6 groups: for drinking, household, farming, washing cars, raising stock, and others. We considered risk only for drinking water and household water because radon is rapidly dispersed before it of other use reach human respiratory organs. We select 565 samples for risk analysis, and applied unit risk which is 6.6210-7 per pCi/L to be recommended by NAS committee. Unit risk was derived from considering radon ingestion and radon inhalation from water use. When estimating risk, we analyzed PDF of concentration and represented risk as 50 and 95 percentile values to consider uncertainty with Monte-Carlo simulation. It results in 10-4 level of their excess cancer risk and in 10-2 level in some areas with high concentration of radon. It must be monitor periodically and take adequate actions in these risky sites. We recommend that it needs to take more survey and finally set guideline for radon regulation in groundwater.