• 한국환경보건학회지
• /
• 제28권2호
• /
• pp.89-98
• /
• 2002

This study was taken in general hospital, hotel, shopping center, underground cafe, school, house, for the purpose of investigating the distribution of indoor radon concentration in urban area, by E-PERM which approved U.S. EPA, between August and November 1999. There are two sampling Places were exceed 148 ㏃/㎥(4 pCi/L; U.S EPA remedial level), difference mean is 24.0㏃/㎥ when compared with underground vs. aboveground indoor radon concentration in the same building and ratio is 1.6, so underground area is higher than aboveground (p<0.05). Influencing factors were examined. They related to the location of sampler(detector) open or near the door is lower radon concentration than inside portion, which explains probably open area has better ventilated air and dilutes indoor radon concentration. Temperature has a negative relationship (p<0.05) with indoor radon concentration and relative humidity has a positive (p<0.05) Simultaneously to investigate water radon concentration, collected piped-water and the results were very low, which is the same in piped-water concentration other countries. In conclusion, underground indoor radon concentration is higher than aboveground. Concentration was related to sampling spot, open portion is lower than inside. Higher the temperature, lower the indoor radon concentrations. On the other hand higher the relative humidity, higher the indoor radon concentrations. Indoor radon concentration is influenced by sampling point, temperature, relative humidity.

• 대한의용생체공학회:의공학회지
• /
• 제39권6호
• /
• pp.243-249
• /
• 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.

• 한국환경보건학회지
• /
• 제45권6호
• /
• pp.658-667
• /
• 2019

Objective: This study was designed to compare construction types and seasonal radon concentrations in dwellings in Jeollabuk-do Province in Korea. Methods: The measurement of indoor radon concentrations in 79 dwellings using alpha-track detectors was performed every three months (seasonally) over one year between 2015 and 2016. Also, Radon concentrations in soil were measured in spring to investigate the correlations between the concentrations in soil and indoor air. Results: The annual average concentration of indoor radon for dwellings was 89.7±72.1(GM: 72.4) Bq/㎥, with a range (min-max) of 17.2 to 505.4 Bq/㎥. The highest indoor radon concentration was measured in winter and the lowest was shown in summer. The geometric mean of radon concentration in winter was 1.03-2.58 times higher than other seasons. Radon concentrations in soil were investigated at the depth of 1 m, and the concentrations ranged from 1,780 Bq/㎥ to 123,264 Bq/㎥. This showed low correlations with indoor radon concentrations.

• 대한방사선기술학회지:방사선기술과학
• /
• 제24권1호
• /
• pp.55-59
• /
• 2001

This study was conducted to find out the radon concentration of indoor air on second floor of a building in Seoul, from January to December in 2000. The following results were achieved ; 1. The annual radon concentration of indoor air was $0.81{\pm}0.35\;pCi/L$ on the average. 2. The time of the highest radon concentration of indoor air was 9 : 00 AM. 3. The radon concentration of indoor air in the year 2000 compared with that in the year 1998 was increased.

• 대한방사선기술학회지:방사선기술과학
• /
• 제19권1호
• /
• pp.51-54
• /
• 1996

This study was conducted to find out the indoor radon concentrations from Jan. 1, to Dec. 31, 1995 in Seoul, and the following results were achieved; 1. The average concentration of indoor radon ranged from $0.51pCi/\ell$ to $0.78pCi/\ell$. 2. The correlation coefficients(r) of radon concentration and indoor meteorological conditions were as follows; 1) temperature : r=0.11 2) atmospheric pressure : r= -0.01 3) humidity : r=0.227.

• KIEAE Journal
• /
• 제1권2호
• /
• pp.21-28
• /
• 2001

Naturally-ocurring short-lived decay products of radon gas in indoor air are the dominant source of ionizing radiation exposure to the general public. It is written in BEIR VI Report(l999l the radon progeny were identified as the second cause of lung cancer next to cigarette or 10 % to 14 %(15,400 to 21,800 persons p.a.) of all lung cancer deaths in USA. Indoor radon concentrations in houses typically result from radon gaining access to houses mainly from the underlying soil. In the States, they have "Indoor Radon Abatement Act" which was converted from "Toxic Substance Control Act" in 1988 to establish the national long-term goal that indoor air should be as free of radon as the ambient air outside of buildings. To review and study techniques for controlling radon, two test cells were constructed for a series of tests and are under measuring indoor and soil gas (underneath of floor slab)radon concentrations according to EPA's measurement protocol. In this paper, important theoretical studies are previewed and the following paper will explain the test results and confirm the theories reviewed to find out suitable coefficients. On the basis of test analysis, it will be described and evaluated various techniques that can be used to mitigate elevated indoor concentration of radon including the control of radon and its decay products.

• Journal of Radiation Protection and Research
• /
• 제32권3호
• /
• pp.97-104
• /
• 2007

전주시에 소재한 아파트의 큰 방과 작은 방을 대상으로 실내 체적과 측정되는 라돈 농도와의 상관 관계를 분석하였다. 또한 실내의 라돈 농도를 측정하여 실내의 시간별 라돈 농도의 변화를 파악하고 이를 토대로 실내 라돈의 년간 피폭선량을 계산하였다. 본 연구를 위하여 각각 8개의 아파트 큰 방과 작은 방을 대상으로 라돈 농도를 측정하였으며, 큰 방의 평균 체적은 $31.59\;m^3$ 그리고 작은 방의 평균 체적은 $16.82\;m^3$이었다. 큰 방의 평균 라돈 농도는 $71.73\;Bq/m^3$, 작은 방의 평균 라돈 농도는 $108.51\;Bq/m^3$로 측정되어 실내 체적과 실내 라돈 농도는 반비례 관계로 나타났다. 밀폐된 실내 라돈 농도의 주 발생원이 건축자재임을 감안하여 건물 벽의 표면적을 체적으로 나누어 계측해 본 결과 표면적/체적의 비가 클수록 측정되는 실내 라돈 농도가 크게 나타났다. 실내 라돈 농도의 하루 중 시간에 따른 변화를 조사한 결과 오전 $8{\sim}10$시에 일 최고 농도($114.5\;Bq/m^3$)를 보였고, 오후 $2{\sim}4$시에 일 최저농도($67.7\;Bq/m^3$)를 나타냈으며, 하루 중 라돈 농도의 변화는 약 $46.8\;Bq/m^3$이었다. 8개 지점의 실내 라돈의 연간 피폭선량을 계산해 본 결과 0.3에서 2.16 mSv/yr사이로 나타나, 일부 아파트의 피폭선량이 국제방사선영향과학위원회(UNSCEAR)가 제시한 수치인 1.3 mSv/yr를 초과했다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제22권5호
• /
• pp.105-111
• /
• 2017

In this study, the variation of indoor and soil radon concentrations were measured at a test bed (detached house), and correlation analysis was performed using linear regression. The results showed that the average concentration of indoor radon was increased by about 20% when the heater was operated in the house, but it was decreased by 15% when the ventilation system was on. In the changes of seasonal radon concentrations, soil and indoor radon concentrations in winter were higher than in summer. Statistical analysis showed a weak correlation between the soil radon and indoor radon, but the correlation (R=0.852, $R^2=0.726$) was relatively high at exhaust condition in the winter. It is difficult to extrapolate the results of the study to the general cases because radon distribution is highly site-specific, but the result of this study could be used as a reference for radon management and reduction of detached house in the future investigations.

• Journal of Radiation Protection and Research
• /
• 제40권3호
• /
• pp.155-161
• /
• 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.

• Nuclear Engineering and Technology
• /
• 제50권3호
• /
• pp.512-518
• /
• 2018

This article measured and analyzed the indoor radon concentrations at one university building in Gyeongju, Republic of Korea, to investigate if there is any relationship between earthquakes and indoor radon concentration. Since 12 September 2016, when two 5.1 and 5.8 magnitude earthquakes occurred, hundreds of aftershocks affected Gyeongju until January 2017. The measurements were made at the ground floor of the Energy Engineering Hall of Dongguk University in Gyeongju over a period between February 2016 and January 2017. The measurements were made with an RAD7 detector on the basis of the US Environmental Protection Agency measurement protocol. Each measurement was continuously made every 30 minutes over the measurement period every month. Among earthquakes with 2.0 or greater magnitude, the earthquakes whose occurrence timings fell into the measurement periods were screened for further analysis. We observed similar spike-like patterns between the indoor radon concentration distributions and earthquakes: a sudden increase in the peak indoor radon concentration 1-4 days before an earthquake, gradual decrease before the earthquake, and sudden drop on the day of the earthquake if the interval between successive earthquakes was moderately longer, for example, 3 days in this article.