This study measured the suspended fungal concentration in indoor multiple facilities nationwide. The regions were selected as representative cities by region: Seoul, Gyeonggi (Incheon), Gangwon, Gwangju, Daejeon, and Busan. A total of 2028 regional comparisons, including department stores, schools, public toilets, libraries, and banks, subway, sports facilities and comparative analysis were conducted for each multi-use facility industry. Among the nationwide, Among the regions, the average concentration of floating mold in indoor multi-use facilities was the lowest in Busan at 394.67 CFU/m3, followed by Gyeonggi and Incheon 487.90 CFU/m3, Seoul 542.84 CFU/m3, Daejeon 809.30 CFU/m3, Gangwon 1,145.22 CFU/m3, Gwangju was 1,371.10 CFU/m3 in the order. Busan was the lowest, and Gangwon was the highest. The reason that Busan, which has a high average temperature and population density, shows a lower mold concentration than Gangwon, is that floating mold in the indoor air is not affected by the external atmospheric environment, population density, and number of facility users. Although it cannot be said that there is no influence of the atmospheric environment, it was found that the indoor environment has different characteristics from the outdoor environment. The importance of air quality management has been confirmed, and further, it is necessary to subdivide the management standards by region and multi-use facilities, and the management standards need to be converted to maintenance rather than recommendations.

In this study, we investigated the Indoor and Outdoor concentrations of PM10 in Y area, Jeollanam-do. We conducted personal exposure concentration estimates, and Exposure and Risk Assessments using the Time-weighted Average Model. The concentration of Indoor PM10 was 49.38 μg/m3 and that of Outdoor PM10 was 48.02 μg/m3, with the Indoor/ Outdoor Ratio value being 1 or more, and it was found that there was an indoor source of pollution. The Indoor/Outdoor Cr ratio value was 1 or more, and the source of Cr was confirmed to be indoor. Based on our analysis, there was a positive correlation between heavy metals Ni, Cr, and Mn (p<0.05). Using the Time-Weighted Average model, we determined the PM10 personal exposure concentration to be 49.36 μg/m3 and confirmed the feasibility of this model in utilizing the PM10 personal exposure concentrations. In this study, the findings are likely to provide useful data that can be used to determine the concentration of indoor pollutants that are not easy to survey. However, to accurately evaluate indoor air quality, more factors need to be considered and evaluated.

Volatile organic compounds (VOCs) are chemicals to which humans are exposed frequently via various mediums, including vehicle emissions that contain fine dust and heavy metals, use of organic solvent building materials, furniture, and smoking. Exposure to high concentrations of VOCs may result in loss of consciousness, paralysis, convulsions, and, in the most severe cases, death. Therefore, the present study investigated the indoor and outdoor concentrations of total volatile organic compounds (TVOC) and five types of VOCs (benzene, toluene, styrene, m,p-xylene, and o-xylene) in apartments, a representative residential environment accounting for ~55% of the housing in the Seoul metropolitan area. The research was conducted over four seasons from May 2020 to February 2021, and the levels of VOC concentrations were analyzed by classifying them by season, weekday/weekend, and indoor/outdoor locations. The seasonal trend in VOC concentrations showed that TVOC concentration was highest in summer, with values of 1630.93 ± 1184.10 μg/m3 and 1610.36 ± 1363.43 μg/m3 for indoor and outdoor environments, respectively. The seasonal trends of the concentrations of the five types of VOCs showed that concentrations of benzene and toluene were highest in spring, the concentrations of m,p-xylene and o-xylene were highest in summer, and the concentration of styrene was highest in winter, irrespective of spatial characteristics such as indoor/outdoor environments. In all four seasons, the indoor concentrations were higher than the outdoor concentrations. These results reveal the spatial and temporal distribution characteristics of the VOCs and so can serve as useful basic data for managing indoor and outdoor levels of VOCs.

Fungi have been known as an irritant or causal agent of asthma. Thus, information on their concentration and diversity in indoor air of asthmatic patient’s houses is valuable for the management of these micro-organisms. The present study was performed to investigate fungal concentration and diversity in indoor air of resident spaces in two adult patient’s houses in winter. Air samples were collected in February of 2018 from living rooms and bedrooms of two asthma patients’ houses located in two different places in Incheon city using an impaction method. The average concentrations of airborne fungi did not exceed the 500 CFU/m3 level which is recommended by the Enforcement Managements of the Indoor Air Quality, Ministry of Environment, Korea. A total of four genera and 23 species were identified based on morphological and molecular methods. Aspergillus and Penicillium were two major genera. Aspergillus pseudoglaucus and Penicillium citrinum were commonly found between the two patient’s houses. Among the identified fungi, three species, Aspergillus venenatus, Penicillium jamesonlandense, and Penicillium salami were found to be unrecorded species in Korea. The morphological and molecular characteristics of these three unrecorded species were described. Since these species produce spores well and a lot, they are considered to be a species that needs management. This study provides basic information on the fungi for indoor air quality management in the living spaces of asthma patients in winter in Korea.

This study was designed to verify what effect the use of a natural ventilation system can have on improving indoor air quality with regard to radon in various concentration ranges in an apartment house. The results show that both high (2~3 times higher than 148 m3) and low (similar to 148 Bq/m3) levels of indoor radon concentrations can be reduced close to and/or below the Korean IAQ guideline within 6 hours when the natural ventilation system is operated at approximately an air change rate of 0.5. In the case of an air change rate of 0.3, however, the indoor radon levels cannot meet the national guidelines and the reduction effect was insufficient with regard to various radon concentrations. Typically, the air change rate of a natural ventilation system is affected by meteorological factors such as temperature, relative humidity, wind speed, pressure. Its effectiveness varies according to such factors, for that reason, the reduction effects on radon did not increase proportionally with the ventilation time in this study.

In order for records to be preserved for a long time without physical and chemical transformation, the preservation environment of the library is very important, and environmental problems must be improved through periodic investigation on the preservation environment. Against this background, this study derived fine dust (PM10) and ultrafine dust (PM2.5) concentration data for the libraries, hallways, and workrooms of the National Archives of Korea over two years. There was a difference in the concentration of fine dust and ultrafine dust among facilities, and there was a change in the concentration depending on the month. Both fine dust and ultrafine dust concentrations were present at less than 10 μg/m³ in the libraries. In the hallways, both fine and ultrafine dust concentrations were highest in July. In the workplaces, the monthly fluctuations in the concentration of fine dust and ultrafine dust were large. And the concentration of fine dust and ultrafine dust in the workplaces were higher than those in the library and hallways. Overall, the concentration of fine dust and ultra-fine dust was measured below the maintenance standards stipulated by the Indoor Air Quality Management Act of the Ministry of Environment of Korea in all the investigated facilities. The results of this study are expected to be used as fundamental information to manage the indoor air quality of the facilities of the National Archives.

This study investigated 180 students’ indoor environmental awareness of rest spaces and measured the indoor and outdoor concentrations of PM10, TVOCs, and HCHO in 8 rest spaces from October 2019. 89.4% of the students responded that they use rest spaces at least once a day and most of the respondents are using rest spaces in the university. The largest number of students responded to the tight space as the main cause of air pollution in rest spaces. 62.1% of the students answered they experienced health symptoms from using rest spaces. Among them, 32.5% said they experienced irritation symptoms of eyes, neck, nose, and 12.1% answered that they experienced headaches. Indoor PM10, TVOCs, and HCHO levels did not exceed indoor air quality recommendations nor the maintenance standard for multi-use facilities. Indoor PM10, TVOCs, and HCHO levels did not exceed indoor air quality recommendations nor the maintenance standard for multi-use facilities. According to the type of rest space, concentrations of PM10, TVOCs, and HCHO were higher among the closed-type than open-type rest space. Even if the concentration of pollutants is less than the environmental standard, continuous exposure may cause negative health effects. In addition, considering that 62.1% of the respondents experienced health symptoms, it is deemed necessary to take measures to manage indoor environments in rest spaces and to develop measures to reduce pollutants.

Radon is a radioactive gas material, which is not detectable by humans because of the absence of color and odor. Radon gas can exist indoors through a number of pathways and long-term exposure to such material can affect the human body, which may result in serious health issues such as lung-cancer. It is thus essential to reduce and maintain indoor radon concentration in order that potential health risks from radon can be diminished. In order to achieve the aforementioned goals, it is requisite to utilize a practical detector which is capable of continuous radon monitoring. In relation to this, a recently developed prototype radon detector, i.e., RS9A, provides highperformance comparable to existing research-grade radon detectors for the purpose of continuous radon monitoring in the air. Furthermore, RS9A is a convenient piece of equipment for use by the public as it is compact in size and affordable. In this paper, we conducted continuous measurements of indoor radon concentrations by using sets of RS9A and evaluated the equivalence of RS9A in terms of quality assurance.

Mold is one of the harmful biological pollutants in the indoor environment. To investigate how the contamination degree of mold existing in the indoor environment differs according to the characteristics of the house, the concentration of mold in the indoor air was investigated for the houses damaged by leakage or flooding. As a result of a survey of 20 houses located in Gyeonggi-do and Chungcheong-do, the concentration of mold in indoor air surprisingly exceeded more than two times the recommended indoor air quality standard of 500 CFU/m3 in all the houses investigated. The fungal concentration was high in houses with condensation and mold odors. As for the housing type, the pollution degree was higher in detached houses than in row houses. As for the type of water damage, mold contamination was higher in the leaky houses than in the flooded houses. The degree of mold concentration was 1,237 CFU/ m3 in the leaky houses. In terms of housing age, pollution was very high in houses over 20 years old. The occurrence of these measured mold concentrations was correlated at a significant level with respect to the properties of the house. This study shows that in the case of water damaged houses, careful management of mold contamination is required.

This study was performed to investigate the characteristics of VOCs and carbonyl compounds emitted by smallscale master, offset, and screen printing facilities. During the printing process, concentration measurements of indoor samples were made at each on the printer equipment and the indoor center of the facility. In each case, the window or door served as natural ventilation, and concentration measurements of outdoor samples were made at each air exit point. The results showed that in all printing facilities, the levels of VOCs and carbonyl compounds were much higher in printer equipment compared to indoor levels. Comparative examination of VOCs between printer equipment and the indoors of the facility, the main species of master and offset printer equipment were Methyl isocyanide, 2,2,6-Trimethyloctane, 2,2-Dimethyldecane, 3,7-Dimethyldecane, Toluene, Acetonitrile, and 3- Methoxy-3-methylbutanol. The main species of the indoors of master and offset facilities were Toluene, 2,2,6- Trimethyl-octane, Isopropyl alcohol, 3-Methoxy–3- methylbutanol, Nonane, and Acetone. However, in the screen printing facility, the printer and indoor emission compounds were the same such as 2-Methyl-cyclopentanone, Cyclohexanone, Ethylbenzene, and p-Xylene. Among the compounds released to the outside, Toluene and Acetone were the most abundant species of VOCs and carbonyl compounds, respectively.

Radon is known to be one of the representative carcinogen materials, and may cause severe health damage to the human body with long-term exposure. Without proper treatment such as natural and mechanical ventilation, indoor radon concentration tends to increase as time passes. In this aspect, it is necessary to maintain indoor radon concentration below the domestic indoor air quality (IAQ) management standard by continuous monitoring. However, the number of practical devices which can detect radon concentration is scarce and most of the existing devices are very costly. Among such devices, the RS9A, a prototype of a radon detector, detects indoor radon concentration and is priced significantly lower compared to other existing radon detectors. In this paper, we investigated the RS9A for the continuous detection of indoor radon gas and compared its performance to a commercially available radon detector (RadonEye). We measured indoor radon concentrations at two separate sites by using both detectors simultaneously. The indoor radon concentrations measured by the aforementioned detectors revealed a high correlation. Therefore, the RS9A can be considered as an appropriate candidate for use as a continuous indoor radon monitoring system.

The goal of this study was to measure the indoor and outdoor fine and ultrafine particulate matter concentrations (PM10, PM1.0) of some houses in Yeosu and in S university in Asan from March to September 2018. PM10 concentration in indoor air in Yeosu area was 18.25 μg/m3, while for outdoor air it was 14.53 μg/m3. PM1.0 concentration in indoor air in the Asan area was 1.70 μg/m3, while for outdoor air it was 1.76 μg/m3, showing a similar trend. Heavy metal concentrations in the Yeosu region were the highest, at Mn 2.81 μg/m3, Cr 1.30 μg/ m3, and Ni 1.11 μg/m3 indoors. Outside, similar concentrations were found, at Cr 3.44 μg/m3, Mn, 2.60 μg/m3, and Ni 1.71 μg/m3. Our analysis of indoor and outdoor PM concentrations in the Asan region, which was carried out using the MOUDI (Micro-orifice Uniform Deposit Impactor) technique, found that PM concentration is related to each particle size concentration, as the concentration of 18 μm and 18-10 μm inside tends to increase by 3.2- 1.8 μm and 0.56-0.32 μm.

In this study, indoor radon concentrations were measured in 56 multiple-use facilities located in Gwangju area from December 2017 to December 2018. The average indoor radon concentration in underground space was 51.70 Bq/m3, and that of the 1st floor was 38.73 Bq/m3, indicating that the indoor radon concentration of underground space was higher than that of the 1st floor. The indoor radon concentration was investigated according to the presence or absence of underground space. The concentration of radon on the 1st floor with underground space was 37.25 Bq/m3, and the concentration of radon on the ground floor without underground space was 47.94 Bq/m3. In the absence of underground space, indoor radon concentration was high. The indoor radon concentration of buildings over 30 years old was 87.26 Bq/m3, indicating a significantly higher indoor radon concentration compared to those of buildings less than 30 years old. The indoor radon concentration was investigated according to the operation of a ventilator. The indoor radon concentration of space without an operating ventilator was 52.17 Bq/m3, and that of space with a ventilator in operation for more than 8 hours per day was 36.31 Bq/m3. This result shows that the indoor radon concentration in the space with an operating ventilator is lower than the space where the ventilator is not in operation. The indoor radon concentration in the space with an operating ventilation system was lower than that on the same floor of the same building, and the indoor radon concentration of enclosed space was about 4.4 times higher than that of open space in the same building. In addition, the indoor radon concentration was measured according to the spatial features. The concentration of indoor radon of enclosed space was 64.76 Bq/m3, which is higher than those of an open space and an active space.

Fungus has been regulated as an air contaminant in indoor environments in Korea. To remove the contaminant, air purifiers have been used in houses. However, not much information on the status of fungal contamination in the indoor air of houses is available. The present study was carried out to investigate fungal concentration and species in the indoor air of houses using air purifiers in winter. The results of indoor air sampling of ten houses located in the cities of Incheon, Seoul, Hwaseong, and Gimpo showed that the level of fungi ranged from 9 CFU/ m3 to 782 CFU/m3. Eight out of ten houses showed a level of less than 165 CFU/m3 indicating that the fungal level is generally low. Only one house exceeded the Korean regulatory standard value of 500 CFU/m3. A total of 175 isolates were obtained and classified as three genera belonging to Aspergillus, Cladosporium, and Penicillium. Among these three genera, 15 species including four Aspergillus spp., two Cladosporium spp., and nine Penicillium spp. were identified. Regarding the detection rate of the 15 identified fungal species, A. niger was the most detected species and followed by Cladosporium cladosporioides. Three to six species were present in the individual house that was investigated. Overall, our results showed that the level of fungal concentration and species diversity are low in the indoor air of houses that use air purifiers in winter.

In this study, we measured the concentration of Particulate Matter(PM10), Formaldehyde(HCHO), and Total Bacteria Count (TBC) at two facilities: day care centers, and postnatal care centers located in the cities of Gyeonggi, Gangwon, Jeolla and Gyeongsang from January 1, 2012 to December 31, 2015. PM10 concentration was similar to the day care centers and postnatal care centers. HCHO concentration was the highest in the postnatal care centers. TBC concentration was the highest in the day care centers. Comparing the different cities, PM10 concentration was the highest in Gyeonggi, HCHO concentration was the highest in Gyeonggi, and TBC concentration was the highest in Gyeonggi. As a result of HCHO's risk assessment, it was found that adults exceeded the carcinogenicity tolerance of 10−6 specified by the US EPA. This study is expected to be helpful in preventing damage to health from the contaminated indoor air at sensitive facilities, and can be used as basic data for indoor air quality management.

봄철 천식환자 가정집 9곳에서 실내 공기를 포집하여 부유진균의 농도 및 다양성을 조사하였다. 조사된 천식환자 가정집의 평균 부유진균 농도는 거실 143 CFU/m³, 방 142 CFU/m³ 이었으며 외기보다 낮았다. 이는 다중이용시설 실내공기질 기준법의 권고기준 기준치 500 CFU/m³를 초과하지 않았음을 보여준다. 총 59균주를 분리하였으며 5속 33종으로 동정하였다. 이 중 병원균으로서 인체에 위해성을 가지고 있는 진균은 4속 12종이었다. 동정된 종 중 Cladosporium crousii, Penicillium maximae, Aspergillus protuberus는 국내에 보고되지 않은 미기록 진균 종으로 확인하였다. 이 중 A. protuberus는 국외에서 인체에 질병을 유발시키는 균으로 알려진 진균이다. 이상의 결과는 천식환자 가정에서 진균의 관리는 정량적 수준에서뿐만 아니라 유해종을 파악하여 관리하는 정성적인 수준에서도 이루어져야 함을 제시한다. 본 연구는 봄철 천식환자 가정집에 존재하는 실내 공기 중 부유진균의 농도 및 다양성에 대한 최초의 연구이다.

In this study, we measured the concentration of Particulate Matter (PM10), Formaldehyde (HCHO), and Total Bacteria Count (TBC) at three facilities: elderly care centers, day care centers, and postnatal care centers located in the cities of Seoul, Sejong, Daegu and Ulsan from January 1, 2012 to December 31, 2015. PM10 concentration was the highest in the day care centers and HCHO concentration was the highest in the postnatal care centers. TBC concentration was the highest in the day care centers. Comparing the different cities, PM10 concentration was the highest in Sejong, HCHO concentration was the highest in Seoul, and TBC concentration was the highest in Daegu. This study is expected to be helpful in preventing damage to health from the contaminated indoor air at sensitive facilities, and can be used as basic data for indoor air quality management.

To obtain basic data on bioaerosols in the indoor environments of houses located adjacent to Gwangyang Iron Works, the concentration and diversity of indoor air molds were comparatively investigated in 33 houses in September of 2016 and 2017, respectively. In areas both adjacent to and nonadjacent to Gwangyang Iron Works, house temperature and humidity ranged from 24~28oC and 47~57%, respectively. Airborne mold concentration was higher in the houses located nonadjacent than in the ones adjacent to the iron works. Interestingly, the level of airborne mold concentration exceeded 500 CFU/m3 in all houses nonadjacent to the iron works. A total of 12 mold species including five pathogenic species were indentified from the investigation. Among the five pathogenic species, the causal agents of otomycosis, Alternaria alternata, Aspergillus fumigatus, and A. niger were present. Overall, Cladosporium cladosporioides was the dominant species. This is the first report on the concentration and diversity of airborne mold in houses located adjacent and nonadjacent to Gwangyang bay industrial complex in Korea.

The purpose of this study was to evaluate the concentration of airborne particulate matter and heavy metals in the houses of the respiratory tract disease patients and a control group of residents in the city of Gwangyang. The particulate matter was measured using a mini-volume air sampler and then weighed three times using a micro balance to calculate the weighted average value. The heavy metals in the particulate matter were extracted using a hot plate and analyzed using an inductively coupled plasma/mass spectrometer. The average concentration of particulate matter in the outdoor air (34.478 μm/m3) was higher than that in the indoor air (16.794 μm/m3), showing a statistically significant difference (p<0.001). The average concentration of copper, manganese and chromium in the indoor and outdoor air were higher in the houses of those in the study group than those of the control group. In addition, there was a generally high correlation between particulate matter in the outdoor air and heavy metals in the indoor and outdoor air concentration (p<0.05).

We measured VOCs and NO2 in the indoor and outdoor air at 125 houses in Jeollanam-do and Gyeongsangnamdo, from March 2007 to January 2008. The concentration of benzene measured in the Gwangyang survey group was higher than in Yeosu and Hadong, and showed a statistically significant difference from Yeosu (p<0.05). The concentration of toluene in outdoor air was highest in the Gwangyang survey group. The concentration of NO2 measured in the Yeosu survey group was higher than in Gwangyang and Hadong, and showed a statistically significant difference from Hadong (p<0.01). According to the results of a correlation analysis, VOCs (benzene, toluene, xylene, ethylbenzene) exposure of individuals showed a significant correlation with the residential indoor air (p<0.01). Also, VOCs of residential indoor and outdoor air showed a significant correlation (p<0.01). The concentration of NO2 exposure of individuals measured in the Yeosu comparison group showed a high correlation with the residential indoor air.