• Journal of radiological science and technology
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• v.46 no.2
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• pp.141-149
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• 2023

The Korea Institute of Radiological and Medical Sciences plans to produce ²²⁵Ac, a therapeutic radio-pharmaceutical for precision oncology, such as prostate cancer. Radon, a radioactive gas, is generated by radium, the target material for producing ²²⁵Ac. The radon concentration is expected to be about 2000 Bq·m^-3. High-concentration radon-generating facilities must meet radioactive isotope emission standards by lowering the radon concentration. However, most existing studies concerning radon removal using activated carbon filters measured radon levels at concentrations lower than 1000 Bq·m^-3. This study measured ²²²Rn removal of coconut-based activated carbon filter under a high radon concentration of about 2000 Bq·m^-3. The ²²²Rn removal efficiency of activated carbon impregnated with triethylenediamine was also measured. As a result, the ²²²Rn removal amount of the activated carbon filter showed sufficient removal efficiency in a ²²²Rn concentration environment of about 2000 Bq·m^-3. In addition, despite an expectation of low radon reduction efficiency of Triethylenediamine-impregnated activated carbon, it was difficult to confirm a significant difference in the results. Therefore, it is considered that activated carbon can be used as a radioisotope exhaust filter regardless of whether or not Triethylenediamine is impregnated. The results of this study are expected to be used as primary data when building an air purification system for radiation safety management in facilities with radon concentrations of about 2000 Bq·m^-3.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.109-118
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• 2016

Objectives: To review reference levels by the international and domestic management and provide the basis for setting occupational exposure limits(OELs) of radon in Korea Methods: Government's organizations with laws and systems for monitoring radon exposure were investigated and compared. There are five laws governing Indoor Air Quality(IAQ) control such as Occupational Safety and Health Act, Indoor Air Quality Control in Public Use Facilities, Etc. Act, School Health Act, Public Health Control Act and Parking Lot Act in Korea. It was surveyed that a total of 32 countries including 24 countries in the European Union(EU), six countries in Asian and two countries in North America setting the reference levels for radon in the world. Results: In Korea, there are set guidelines for radon in the Ministry of Environment and the Ministry of Education. Reference levels of radon for existing dwellings were $150{\sim}400Bq/m^3$ for Western European countries, and $200{\sim}1,500Bq/m^3$ in Eastern European countries. Approximately 67% of those EU countries were set up $400Bq/m^3$ to the standards for existing dwellings. EU countries such as Luxembourg, Finland, Norway, Sweden and Russia had adopted mandatory level for radon. Radon guidelines for new dwellings were set more strictly reference level($200Bq/m^3$) than existing dwellings. Conclusions: International organizations such as ICRP, UNSCEAR and NCRP, etc. had recommended the guidelines for radon. It was calculated the relation of the dose conversion factors with the annual effective doses. the OELs of radon suggest to need to establish $150Bq/m^3$ for office room and $400{\sim}1,000Bq/m^3$ for the workplace.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.329-334
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• 2018

Radon which is natural component of air is a colorless and odorless radioactive gas. Radon exposure can also occur from some building materials if they are made from radon-containing substances by breathing. In this study, The radiation dose of radon concentration was detected at 8 buildings of the A university during 3-month from June. 2017 to August. 2017. We detected indoor radon exposure at 8 building of the university and estimated annual effective dose. The radon concentration of Hall G and Hall F of the A university represented 81 and $14Bq/m^3$ respectively and average indoor radon concentration represented $41.63Bq/m^3$. Average effective dose was estimated 0.40 mSv/y, maximum effective dose was 0.78 mSv/y and minimum effective dose was 0.13 mSv/y respectively. University is the place that students spend the almost whole time. We suggest ventilation and appropriate management of a building, which could reduce the natural radiation exposure by radon concentration.

• Journal of Environmental Health Sciences
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• v.33 no.4
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• pp.264-275
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• 2007

The objective of this study was to offer basic and scientific data for decision-making of policy for improvement and management of radon, natural radiation gas, in Korea and to form the foundation of radon related international cooperation. Therefore, this study collected and re-analysed the articles on exposure of radon in various indoor environment in journals related environment in Korea since 1980 and estimated the annual exposure dose and effective dose by exposure of radon received by inhabitants in them. The highest pooled average radon concentration of $50.17{\pm}4.08\;Bq/m^3$ (95% CI : $42.17{\sim}58.17\;Bq/m^3$) was found in dwelling house among various indoor environment. All of pooled average radon concentration estimated in this study showed lower than the guideline concentration ($148\;Bq/m^3)$ of US EPA and the Korean Ministry of Environment. The annual effective dose received by inhabitants in various indoor environment was estimated 1.071 mSv/yr. That is equal to annual effective dose (1.0 mSv/yr) by exposure of radon estimated by UNSCEAR.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.115-125
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• 2023

Objectives: This study was conducted to measure the level of radon in the air at a highway tunnel construction site in a gneiss area using the New Austrian Tunneling Method (NATM) and to evaluate exposure levels by occupation. Methods: Radon concentrations in the air were measured using E-PERM at points 300 m, 600 m, and 900 m from the tunnel entrance during the excavation and waterproofing work inside the tunnel. In addition, radon concentrations were measured during external excavation to compare with the inside of the tunnel. Personal exposure levels for major occupations including tunnel workers, construction equipment operators, waterproofers, shotcrete workers, and safety and health managers who participated in the construction were estimated using radon concentration measured in the work process area and working hours by occupation. Results: As a result of a total of 77 radon measurements, the geometric mean (GM) concentration was 71.1 Bq/m³, and the maximum concentration was 127.3 Bq/m³, which was below the indoor air quality criteria. Radon concentration by process decreased in the order of the tunnel excavation process (GM= Bq/m³, GSD=1.2), waterproofing process (GM=73.35 Bq/m³, GSD=1.2), and outside excavating process (GM=45.28 Bq/m³, GSD=1.2). Processes inside the tunnel were significantly higher than outside excavating processes (p<0.05). There was no statistically significant difference in radon concentration measured inside by distance from the tunnel entrance, but the innermost point of the tunnel, 900 m (GM=79.24 Bq/m³, GSD=1.27), measured the highest. Conclusions: The occupation with the highest individual exposure to radon was tunnel worker (64.16 Bq/m³), followed by construction equipment driver (64.04 Bq/m³) and waterproofer (63.13 Bq/m³).

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.2
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• pp.1-7
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• 2023

Purpose: The purpose of this study is to investigate the characteristics of airborne radon concentration by season in public-use facilities in South Korea. Research design, data and methodology: The data is provided by the public data portal, and public-use facilities nationwide where radon in the air is measured are specialized sanatorium for senior citizens, libraries, childcare facilities, postpartum care centers, medical institutions, funeral halls, underground shopping malls, and underground subway stations. Results: The facility with the highest radon concentration in public-use facilities was childcare facilities with an average of 50.2 ± 21.7 Bq/m³, while the average of medical institutions was the lowest at 24.8 ± 5.7 Bq/m³. The season with the largest difference in average radon concentration between childcare facilities and medical institutions was in the order of fall (28.6 Bq/m³), followed by winter (28.1 Bq/m³), spring (23.0 Bq/m³), and summer (22.0 Bq/m³). Conclusions: The main concentration levels of each public-use facility shown in this study are all below domestic and international standards, but there is a significant concentration difference between facilities. By season, winter showed the highest average concentration (40.6 ± 21.3 Bq/m³) and summer showed the lowest average concentration (23.8 ± 14.0 Bq/m³).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.224-225
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• 2018

Modern people are more interested in the indoor environment as they spend more time indoors than in the past. Among the air pollutants in the indoor air, ladon gas is a colorless, tasteless, odorless, inert gas produced by nuclear decomposition of naturally occurring uranium in rocks and soils. It has been proven that ladon gas is introduced into the room through cracks on the floor of the building or basement wall, and it causes various diseases such as lung cancer when exposed to radon during human breathing. The US Environmental Protection Agency (EPA) specifies 4pCi / L as a necessary measure for radon, and the Korea Environmental Protection Agency has implemented comprehensive indoor radon management measures since 2007. Therefore, in this study, we intend to adsorb and reduce radon in indoor air pollutants.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.139-146
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• 2001

Modern people stay at indoor places about 90% of a day. Radon-222 is a gas produced radioactive decay of the element radium. And, radon is one of the major indoor air pollutants moves into the underground space through various routes and is considered to cause lung c hurting the lung tissues, In this study, we measured the subway radon level at 9 stations o According to test results, we can figure out the concentration of radon by lines, times, and m points. So, it was found that ventilation conditions are the most important factors in the su quality. Finally, we suggested effective and economic management methods of air pollution subway.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.286-295
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• 2022

In this study, the concentration distribution of indoor radon in Daejeon Metropolitan City was investigated and the reduction efficiency was evaluated by applying the radon reduction methods. Based on the results of the National Institute of Environmental Research, indoor radon measurements were conducted on 24 selected houses, and the average value of District A was 261 Bq/m3, far exceeding the standard, and even in the same house, indoor radon concentration was affected by measurement point and time. In the case of eight houses that applied the soil venting method to reduce radon, the indoorradon level was significantly lowerthan the standard value, and the average reduction efficiency was also around 55%, indicating a good reduction effect. In addition, the average reduction efficiency was around 90% in the two houses that carried out the shielding method, showing the very excellent effect of the indoorradon reduction. Even if the same reduction method is applied when reducing radon, the reduction efficiency may vary depending on various factors such as the structure of the building, the frequency of ventilation, and the season, so it is necessary to accurately evaluate the effectiveness of the reduction method in the future. Based on this, it is necessary to establish indoor radon management measures in Daejeon Metropolitan City to reduce human harm caused by radon exposure.

• Journal of Environmental Health Sciences
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• v.47 no.4
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• pp.330-338
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• 2021

Background: This study was conducted to provide background information for the proper management of radon contamination in apartments using mechanical ventilation facilities in residential environments. Objectives: To this end, this study compared and evaluated changes in radon concentrations based on different operating intensities of mechanical ventilation with or without natural ventilation. Methods: For the continuous measurement of radon concentrations, an RAD7 instrument was installed in four apartments equipped with a ventilation system. The measurements were done for comparison of ventilation types and different ventilation intensities ("high", "middle", "low"). Results: The results confirmed that both mechanical and natural ventilation sufficiently reduced the radon concentration in the apartments. In particular, mechanical ventilation at "high" intensity was the most effective. Natural ventilation combined with mechanical ventilation and then natural ventilation alone were the second and the third most effective, respectively. Conclusions: When using ventilation to reduce indoor radon concentrations, it is most effective to operate mechanical ventilation ("high") or natural ventilation and mechanical ventilation at the same time. In cases where mechanical ventilation is available alone, it is recommended to operate it at a minimum of "middle" intensity.