• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.611-612
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• 2009

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.374-383
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• 2012

In this study, we have observed the airborne radon levels in the subway cabins before and after platform screen doors (PSD) installation. The measurements have been conducted at Seoul metropolitan subway lines in 2008, 2009 and 2010. The mean concentration of the radon inside subway cabins were increased by approximately 53% from $20.1Bq/m^3$ to $30.8Bq/m^3$ by installing PSD. After PSD installation, measured values for the different lines were rather different, and varied between 8.2 and $76.5Bq/m^3$. And mean radon concentrations were in the decreasing order for subway lines 5, 6, 7, 8, 3, 4, 2, 9 and 1. It was also found that the indoor radon concentrations in the subway cabins were highly dependent on the management approach of a ventilation system at the subway stations. By assuming an average of $720\;h\;year^{-1}$ and $2,880\;h\;year^{-1}$ spent in subway cabin, effective doses to passengers and employee were estimated. The expected annual effective dose, in case of an equilibrium factor of 0.4, were $0.07mSv\;y^{-1}$ and $0.26mSv\;y^{-1}$, respectively.

• Analytical Science and Technology
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• v.35 no.1
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• pp.32-40
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• 2022

The concentrations of radon in the atmosphere were measured at the Gosan site of Jeju Island during 2017-2018, in order to investigate the time-series variation characteristics and the dependency of airflow transport pathways. The mean ²²²Rn concentration was 2,480 mBq m^-3, and its monthly concentration in November was 3,262 mBq m^-3, more than twice as that in July (1,459 mBq m^-3). The diurnal radon concentrations increased throughout the nighttime to the maximum (2,862 mBq m^-3) at around 7 a.m., then gradually decreased throughout the daytime by the minimum (1,997 mBq m^-3) at around 3 p.m. The seasonal and monthly variations of CO, NO₂, O₃ showed a roughly similar pattern to that of radon for the same period, as high in winter and low in summer. The cluster back trajectory analysis described that about 60 % of overall airflow pathways was influenced by the airflow from China. The concentrations of radon and gaseous pollutants were relatively high as the airflow was influenced by China continent, but comparatively much lower as influenced by the northern Pacific Ocean.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.1-13
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• 2018

The radon concentration in soil varies with environmental factors such as atmospheric temperature and pressure, rainfall and soil temperature. The effects of these factors, therefore, should be differentiate in order to analyzed the anomalous radon variation caused by earthquake events. For these reasons, a comparative analysis between the radon variations with environmental factors and the anomalous variations caused by Gyeong-ju earthquake occurred in September 12, 2016 has been conducted. Radon concentration in soil and environmental factors were continuously measured at a monitoring ste located in 58Km away from earthquake epicenter from January 01, 2014 to May 31, 2017. The co-relationships between radon concentration and environmental factors were analyzed. The seasonal average radon concentration(n) and the standard variation(${\rho}$) was calculated, and the regions of ${\pm}1{\rho}$ and ${\pm}2{\rho}$ deviations from seasonal average concentration were investigated to find the anomalous radon variation related to Gyeong-ju earthquake. Earthquake effectiveness and q-factor were also calculated. The radon concentration indicated the seasonal variation pattern, showing high in summer and low in winter. It increases with increasing air temperature and soil temperature, and has the positive co-relationships of $R^2=0.9136$ and $R^2=0.8496$, respectively. The radon concentration decreases with increasing atmospheric pressure, and has the negative co-relationships of $R^2=0.7825$. Four regions of ${\pm}2{\rho}$ deviation from average seasonal concentration (A1: 7/3~7/5, A2: 7/18, A3: 8/4~8/5, A4: 10/17~10/20) were detected before and after Gyeong-ju earthquake. A1, A2, A3 were determined as the anomalous radon variation caused by the earthquake from co-relationship analyses with environmental factors, earthquake effectiveness and q-factor. During the period of anomalous radon variation, correlation coefficients between radon concentration and environmental factors were significantly lowered compared to other periods such as air temperature ($R^2=0.2314$), soil temperature ($R^2=0.1138$) and atmospheric pressure ($R^2=0.0475$). Annual average radon concentration was also highest at 2016, the year of Gyeong-ju earthquake.

• The Journal of the Petrological Society of Korea
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• v.18 no.4
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• pp.279-291
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• 2009

Radon is a natural radionuclide originated from radioactive decay of radium in rocks and soil. It is colorless, odorless and tasteless elements that mainly distributed as gaseous phase in soil pore space. The present study analyzed the characteristics of long-term radon variation in granitic residual soil at Mt. Guemjeong in Guemjeong-gu, Busan and determined the effects of atmospheric temperature, rainfall and soil temperature and moisture. Periodic measurements of radon concentrations in soil gas were conducted by applying two types of in-situ monitoring methods (chamber system and tubing system). Radon concentration in soil gas was highest in summer and lowest in winter. The variations in soil temperature and atmospheric temperature were most effective factors in the long-term radon variations and showed positive co-relations. The air circulation between soil air and atmosphere by the temperature difference between soil and atmosphere was analyzed a major cause of the variation. However, other factors such as atmospheric pressure, rainfall and soil moisture were analyzed relatively less effective.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.05a
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• pp.148-149
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.05a
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• pp.260-261
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.279-281
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• 2000

발암성 물질로 알려진 라돈($^{222}Rn$)은 원래 불활성기체로 자연계에 널리 존재하는 자연방사능으로 암석이나 토양 같은 지각물질에서 발생하는 우라늄($^{238}U$) 붕괴계열인 라듐($^{226}Ra$)의 붕괴과정에서 생성되는 방사성 가스이다. 라돈($^{222}R$)은 $\alpha$붕괴에 의하여 $^{218}Po$, $^{214}Po$등의 자핵종(Radon daughter)을 생성하며, 최종적으로 납($^{210}Pb$)으로 변한다 라돈이 폐에 흡입되면 붕괴하면서 $\alpha$방사선을 방출하는데, 이것이 인체의 세포를 죽이거나 염색체를 손상시킬 수 있으며, 폐암의 발생 위험률을 높이는 것으로 보고되었다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.376-378
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• 2005

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.432-433
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• 2006