• 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 Environmental Science International
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• v.12 no.6
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• pp.677-688
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• 2003

The purpose of this study was to predict occurrence of earthquakes in Korea by measuring the concentration of radon radioactivity in the air and in the underground water. Two monitoring systems of radon concentration detection in the air were installed in Seoul, East Coast area, whereas of radon concentration in the underground water in Kyungju area during December, 1999 to June, 2001. The distribution of radon concentration in the air in Seoul is as follows Winter(10.10 $\pm$ 2.81 Bq/㎥), autumn(8.41 $\pm$ 1.35 Bq/㎥), summer(5.83 $\pm$ 0.05 Bq/㎥) and spring (5.34 $\pm$ 0.44 Bq/㎥), whereas the distribution of radon in the air in the East Coast area showed some difference as follows : autumn (14.08 $\pm$ 5.75 Bq/㎥), Summer (12.04 $\pm$ 0.53 Bq/㎥), Winter (12.02 $\pm$ 1.40 Bq/㎥) and spring (8.93 $\pm$ 0.91 Bq/㎥). In the meanwhile, the distribution of radon in the water is as follows : spring (123.59 $\pm$ 16.36count/10min), Winter (93.95 $\pm$ 79.69counter/10min), autumn (68.96 $\pm$ 37.53counter/10min) and spring (34.45 $\pm$ 9.69counter/10min). The daily range of the density of radon concentration in Seoul and East Coast area was between 5.51 Bq/㎥ - 9.44 Bq/㎥, 7.15 Bq/㎥ - 15.27 Bq/㎥, respectively. Correlation of the distributions of radon concentrations in the air and in underground water with earthquake showed considerable variations of radon concentration before the occurrence of the earthquake. The results suggested that radon radioactivity seemed to be helpful for the prediction of the occurrence of earthquake.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.189-214
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• 2000

Three study areas of Kwanak campus(Seoul National University), Gapyung and Boeun were selected and classified according to bedrock types in order to investigate soil-gas radon concentrations. Several soil-gas samples showed relatively high radon concentrations in the residual soils which derived from granite bedrock. It also showed that water content of soil and the degree of radioactivity disequilibrium was a secondary factor governing radon emanation and distribution of radon radioactivity. The results of radon concentrations and working levels for forty rooms in Kwanak campus, Seoul National University, showed that indoor basement rooms under poor ventilation condition can be classified as high radon risk zone having more than EPA guideline(4 pCi/L). Some results of section analysis which was surveyed in the fault zone of Kyungju and Gapyung area confirmed the existence of fault-associated radon anomalies with a meaning of radon risk zone.

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.94-98
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• 2005

This study was carried out to provide radon concentration and exposure in building. The average radon concentrations of building was measured 1.37 pCi/L in basement, 0.95 pCi/L in 1st layer, 0.74 pCi/L in 2nd layer, 0.56 pCi/L in 3rd layer, and 0.4 pCi/L in 4th layer, respectively. The average radon concentration of basement was measured the higher than any other stairs. Daily average distribution of radon concentrations in building shown that radon concentrations measured in morning at 8hr was the highest value. Monthly average distribution of radon concentrations shown 0.28 ${\pm}$ 0.17 pCi/L in April and 0.82 pCi/L in December that was the highest value. The average concentrations of radon was measured 0.38pCi/L in spring. 0.44 pCi/L in summer, 0.53 pCi/L in autumn, and 0.67 pCi/L in winter, respectively. This result shown that the average concentrations of radon in winter was the higher than any other seasons. That reasons was supposed that effect of number of exchanges and using air conditions was the higher in summer than winter.

• Journal of Environmental Health Sciences
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• v.46 no.3
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• pp.245-255
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• 2020

Objective: The present study analyzed domestic and overseas academic journals to understand the research status and characteristics of radon concentration distribution in Korea in accordance with environmental conditions. Methods: As part of the meta-analysis, pooled average concentration was calculated using an inverse variance-weighted average of the arithmetic means and standard deviations among the investigated values. Using the obtained pooled average concentration, a Monte-Carlo simulation was performed to increase the reliability of the occurrence possibility of the calculated concentration distribution. A total of 38 research articles were selected, including 27 articles published in domestic academic journals and 11 articles published in foreign academic journals. Results: The comparison results showed differences in radon concentration distribution in accordance with regional and topographical characteristics. Conclusion: Currently, even though research into radon is steadily picking up the pace in Korea much remains to be done. Additional research is thus needed to establish a baseline for radon emissions in Korea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.333-351
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• 2017

Objectives: This study examines the relationships between indoor radon concentrations and distribution from soil geological mapping in the Hwacheon and Jangsu areas. Methods: GIS and a pivot table were used for inquiries about indoor radon contents, soil characteristics, and geological differences. Results: The Hwacheon area was characterized by the presence of normal and reverse faults as a passage of runoff for radon, sufficient occurrences of minerals containing uranium within granite as a radon source, a high concentration of radon within the granite area and clear differences of radon concentrations between granitic and metamorphic areas. The Jangsu area was characterized by the presence of normal faults, wide distributions of alluvium, and ambiguities on radon concentrations indoors among areas of geological differences. Considering the granite area and alluvium surrounded with granite areas, the characteristics of radon concentrations within soils and indoors in the Jangsu area are similar to those of the Hwacheon area. High concentrations are found with entisol and inceptisol in the Hawcheon area, but with entisol, inceptisol, and ultisol in the Jangsu area. High radon concentrations are found in sandy loam and/or loam. High concentrations are found in recently constructed or brick buildings, but low concentrations in traditional or prefabricated houses showing a high possibility of outward flow. Conclusions: The overall results suggest that radon concentrations in the Hwacheon and Jangsu area are dominantly influenced by geological characteristics with additional artificial influences.

• 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 Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.469-480
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• 2004

The radon concentrations were measured to survey distribution of radon concentrations in Seoul subway stations. The radon concentrations in air and water were measured at seventeen subway stations(Mapo, Chungjongno, Sodaemun, Kwanghwamun, Chongno3ga, Ulchiro4ga, Tangdaemun, Sangildong on Line 5;Nowon, Chunggye, Hagye, Kongnung, Taenung, Mokkol, Chunghwa, Sangbong, Myomok on Line 7) using the $RAdtrak^{TM}$ radon gas detector, Pylon AB-5 continuous passive radon detector and liquid scintillation counting method from January to May 1999. The major results obtained from this study were as follows: The long-term mean concentrations of radon were $61.8\;Bq/m^3$ in office, $78.9\;Bq/m^3$ in platform, $38.2\;Bq/m^3$ in concourse and $20.1\;Bq/m^3$ in outdoor, respectively. These levels were less than the action level ($148\;Bq/m^3$) of the U.S. EPA. The highest level of short-term mean concentrations was $116.55\;Bq/m^3$ at Chongno3ga station on the 5th line subway stations, while the lowest mean concentration was $19.55\;Bq/m^3$ at Mokkol station on the 7th line subway stations. The highest concentration of radon in the road water and storing underground water in the subway stations was $234.7\;KBq/m^3\;and\;155.5\;KBq/m^3$ in Sodaemun subway station, respectively. The results suggest that radon concentration in subway stations seems to be affected by ventilation and radon concentratin in underground water in the subway stations.

• Journal of Soil and Groundwater Environment
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• v.22 no.5
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• pp.105-111
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• 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 Environmental Health Sciences
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• v.28 no.2
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• pp.89-98
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• 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.