• Journal of Cancer Prevention
• /
• 제23권4호
• /
• pp.197-197
• /
• 2018

• 한국산업보건학회지
• /
• 제16권1호
• /
• pp.54-67
• /
• 2006

This study was performed to deduct the extension possibility of the standards establishment for $NO_2$, $O_3$, Asbestos, Radon, total volatile organic compounds (TVOC) excluded in the indoor air part of Industrial Safety Acts in Korea. The air pollutants were sampled for 30 office buildings from August to September, 2005 in the metropolitan area. The airborne concentrations of $NO_2$, $O_3$, Radon and TVOC were 0.0092 ppm, 0.0035 ppm, 0.57 pCi/L and $423{\mu}g/m^3$, respectively. The management plan and reduction methods is required in the aspect of indoor air quality(IAQ) because the emission sources of those also exist in indoor as well as outdoor even though those were not exceeded the standards of the Ministry of Environment in Korea. The standard for TVOC in the new and remodeling office has to be established based on the risk assessment when hazard index exceeded "1" in the worst case scenario. In the state of art, the management of each volatile organic compounds has a difficulty due to not enough data for toxicological reference. Therefore, it is suggested that first of all, the standard for TVOC be established and then expanded to each materials for decision-making of improvement of IAQ in office.

• Nuclear Engineering and Technology
• /
• 제54권4호
• /
• pp.1431-1438
• /
• 2022

In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K were 93, 77, 92 and 938 Bq kg^-1, respectively. The average results for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y^-1, respectively. The average emanation fraction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30×10^-3, 4.26×10^-3, 0.62×10^-3, and 25.61×10^-3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

• 자원환경지질
• /
• 제31권3호
• /
• pp.215-222
• /
• 1998

The radon (Rn-222) potential of metropolitan subway stations and soils in Seoul city were delineated using alpha-track filter and EDA-200 radon detectors, respectively. The uranium (U) and thorium (Th) contents were also determined using a Multi Channel Analyzer to identify the sources of radon gas. The average U concentrations in Seoul varies according to basement rock types. For example, there is $9.40{\pm}10.11ppm$ in the Precambrian metasedimentary rock (PM), $9.08{\pm}2.85ppm$ in the Jurassic Kwanaksan granite (JK) and $4.94{\pm}1.43ppm$ in the Jurassic Seoul granite (JS). Uranium contents in soil samples are $10.30{\pm}4.74ppm$ in JK, $10.10{\pm}7.43ppm$ in PM and $6.69{\pm}3.95ppm$ in JS and these closely reflect the content of uraniferous minerals. The levels of soil radon are $604{\pm}273pCi/L$ in JK, $502{\pm}275$ in JS and $262{\pm}211pCi/L$ in PM. The soil radon concentrations are shown to reflect soil permeability and porosity rather than their U contents. The mean indoor radon contents in subway stations are $1.50{\pm}0.62pCi/L$ on the 4th line, $1.41{\pm}0.95pCi/L$ on the 3rd line, $0.84{\pm}0.13pCi/L$ on the 1st line and $0.80{\pm}0.25pCi/L$ on the 2nd line. The subway stations located in the JK have the highest average radon concentration with $2.04{\pm}0.65pCi/L$, where levels of $1.57{\pm}0.81pCi/L$ occur in the JS and $0.80{\pm}0.23pCi/L$ in the PM. The highest radon levels of 4.1 pCi/L occur mainly in Keongbokkung station on the 3rd line and these exceed 4 pCi/L of the US EPA action level.

• Journal of Radiation Protection and Research
• /
• 제46권3호
• /
• pp.127-133
• /
• 2021

Background: Phosphogypsum is material produced as a byproduct in fertilizer industry and is generally used for building materials. This material may contain enhanced radium-226 (²²⁶Ra) activity concentration compared to its natural concentration that may lead to indoor radon accumulation. Therefore, an accurate measurement method is proposed in this study to determine ²²⁶Ra activity concentration in phosphogypsum sample, considering the potential radon leakage from the sample container. Materials and Methods: The International Atomic Energy Agency (IAEA) phosphogypsum reference material was used as a sample in this study. High-purity germanium (HPGe) gamma spectrometry was used to measure the activity concentration of the ²²⁶Ra decay products, i.e., ²¹⁴Bi and ²¹⁴Pb. Marinelli beakers sealed with three different sealing methods were used as sample containers. Due to the potential leakage of radon from the Marinelli beaker (MB), correction to the activity concentration resulted in gamma spectrometry is needed. Therefore, the leaked fraction of radon escaped from the sample container was calculated and added to the gamma spectrometry measured values. Results and Discussion: Total activity concentration of ²²⁶Ra was determined by summing up the activity concentration from gamma spectrometry measurement and calculated concentration from radon leakage correction method. The results obtained from ²¹⁴Bi peak were 723.4 ± 4.0 Bq·kg^-1 in MB1 and 719.2 ± 3.5 Bq·kg^-1 in MB2 that showed about 5% discrepancy compared to the certified activity. Besides, results obtained from ²¹⁴Pb peak were 741.9 ± 3.6 Bq·kg^-1 in MB1 and 740.1 ± 3.4 Bq·kg^-1 in MB2 that showed about 2% difference compared to the certified activity measurement of ²²⁶Ra concentration activity. Conclusion: The results show that radon leakage correction was calculated with insignificant discrepancy to the certified values and provided improvement to the gamma spectrometry. Therefore, measuring ²²⁶Ra activity concentration in TENORM (technologically enhanced naturally occurring radioactive material) sample using radon leakage correction can be concluded as a convenient and accurate method that can be easily conducted with simple calculation.

• 한국방사선학회논문지
• /
• 제14권7호
• /
• pp.881-889
• /
• 2020

본 연구는 건물의 저층과 고층에서 환기와 공기정화 식물을 통한 라돈의 농도 변화를 정량적으로 측정하고자 하였다. 건물의 저층과 고층에서 라돈 농도 측정을 위해 시간을 설정하고 라돈 측정기를 이용하여 실내를 폐쇄 했을 때와 환기, 공기정화식물을 배치했을 때의 라돈 농도를 각각 측정하여 비교하였다. 폐쇄, 환기, 공기정화식물 배치에 따라 라돈 농도 변화에 유의한 차이를 보이는지 검증하고자 일원배치 분산분석(One-way ANOVA)를 시행하였다. 실험 결과 건물의 저층과 고층에서 환기와 공기정화식물 배치를 통한 라돈 농도의 감소는 통계적으로 유의한 차이를 보였으며, 환기와 공기정화식물을 배치 했을 때에는 통계적으로 유의한 차이점을 나타내지 않았다. 따라서 건물내 환기 뿐만 아니라 공기정화식물을 적절히 활용하면 라돈 농도를 효과적으로 감소시킬 수 있을 것으로 사료된다.

• 한국입자에어로졸학회지
• /
• 제13권2호
• /
• pp.87-95
• /
• 2017

Radon ($Rn^{222}$) is a radioactive gas and is found at high concentrations underground. Investigations were done in many years specifically on public transportations such as in the subway stations, concourses and platforms for these are located underground areas. This study correlates the $Rn^{222}$ concentrations with the Particulate Matter (PM) concentration for the gas could be attached or trapped inside these particles. It was done on the opening subway tunnel of Miasageori Station going to Mia Station (Line 4) last August 2016. Based on the result, the $Rn^{222}$ were more influenced on the mass ratio (%) of PM present in the air instead of its mass concentration (${\mu}g/m^3$). As the $PM_{10}$ mass ratio increases ($42.32{\pm}1.03%$) during morning rush-hours, radon starts to increase up to $0.97{\pm}0.03pCi/L$. But during the afternoon $Rn^{222}$ concentrations decreased while the composition were stable at $22.96{\pm}3.0%$, $39.04{\pm}0.6%$ and $38.01{\pm}0.3%$ in $PM_1$, $PM_{2.5}$ and $PM_{10}$ respectively. It was then assumed that it could be the composition of the morning hours of the station were influencing the concentration of the radon.

• Journal of Preventive Medicine and Public Health
• /
• 제55권3호
• /
• pp.273-279
• /
• 2022

Objectives: The aim of this study was to present the baseline results of a pilot project conducted to evaluate the effectiveness of lung cancer screening using low-dose chest computed tomography (CT) in regions with excessive radon levels in the Republic of Kazakhstan. Methods: In total, 3671 participants were screened by low-dose chest CT. Current, former, and never-smokers who resided in regions with elevated levels of radon in drinking water sources and indoor air, aged between 40 and 75 with no history of any cancer, and weighing less than 140 kg were included in the study. All lung nodules were categorized according to the American College of Radiology Lung Imaging Reporting and Data System (Lung-RADS 1.0). Results: Overall, 614 (16.7%) participants had positive baseline CT findings (Lung-RADS categories 3 and 4). Seventy-four cancers were detected, yielding an overall cancer detection rate of 2.0%, with 10.8% (8/74) stage I and a predominance of stage III (59.4%; 44/74). Women never-smokers and men current smokers had the highest cancer detection rates, at 2.9% (12/412) and 6.1% (12/196), respectively. Compared to never-smokers, higher odds ratios (ORs) of lung cancer detection were found in smokers (OR,2.48; 95% confidence interval [CI], 1.52 to 4.05, p<0.001) and former smokers (OR, 2.32; 95% CI, 1.06 to 5.06, p=0.003). The most common histologic type of cancer was adenocarcinoma (58.1%). Conclusions: Implementation of low-dose CT screening for lung cancer in regions with elevated radon levels is an effective method for both smokers and never-smokers.

• 한국주거학회논문집
• /
• 제9권1호
• /
• pp.143-152
• /
• 1998

This study aims to suggest ventilation design data for Public Entertainment Facilities in relation to Indoor Air Quality. The concentration of indoor air pollution such as CO, CO2, RH, Radon, HCHO, TSP was investigate, and the reguired ventilation rate of Public Rooms was calculated. As resuits of this study, the following conclusion could be obtained. Field measurement of P.E.F reveals that the concentration of CO2 was mist polluted and higher than IAQ standard, while that of other pollutats did not exceed the standard. In underground the concentration of CO2 increased 1130ppm(2 persons) 2170ppm(4 persons) 1970ppm(6 persons). The CO2 pollution was serions problem in underground more than second floor, in only exhaust ventilation system more than exhaust and supply system.

• 한국대기환경학회:학술대회논문집
• /
• 한국대기환경학회 2000년도 추계학술대회 논문집
• /
• pp.365-366
• /
• 2000

라돈은 암석이나 토양 같은 지각물질에서 발생되는 우라늄($^{238}$ U) 붕괴계열인 라듐($^{226}$ Ra)의 붕괴과정에서 생성된다. 라돈($^{222}$ Rn)은 붕괴하면서 $\alpha$방사선을 방출한다. $\alpha$ 붕괴에 의하여 $^{218}$ Po, $^{214}$ Po, $^{214}$ Bi 등의 자핵종(Radon daughter)을 생성하며, 이 과정에서 인체의 세포를 죽이거나 염색체를 손상시킬 수 있으며, 폐암의 발생 위험률을 높이는 것으로 보고되었다$^{1)}$ . 라돈은 건물의 균열, 연결부위, 혹은 배수관이나 오수간, 주변의 틈을 통해서 실내로 유입된다. (중략)