• Environmental Analysis Health and Toxicology
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• 제24권3호
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• pp.203-211
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• 2009

A lesser degree of research is available with respect to indoor radon characteristics associated with occupants' exposure. The present study evaluated the radon levels in several public-access buildings or underground facilities, and their temporal variation in underground facilities. Radon measurements were conducted in 2005 and 2006, utilizing a continuous radon detector. A solid alpha detector (RAD7) was utilized to measure indoor radon levels. The mean radon concentrations obtained from the building or facilities were in a descending order: platforms of Daegu subway line 2, 2005 (32 $Bq/m^3$), hot-air bathroom (14 $Bq/m^3$), basement of office building (14 $Bq/m^3$), underground parking garage (14 $Bq/m^3$), underground shop (12 $Bq/m^3$), nursery (10 $Bq/m^3$), platforms of Daegu subway line 2, 2006 (9.0 $Bq/m^3$), platforms of Daegu subway line 1, 2006 (8.9 $Bq/m^3$), supermarket (7.9 $Bq/m^3$), hospital (7.3 $Bq/m^3$), and second-floor of office building (5.7 $Bq/m^3$). In general, underground-level facilities exhibited higher radon levels as compared with ground-level facilities. It was suggested that ventilation is an important parameter regarding the indoor levels of a subway. There was a decreasing or increasing trend in hourly-radon levels in a subway, whereas no trend were observed in a basement of office building. In addition, the radon levels in the subway lines 1 and 2 varied according to the platforms. The radon levels in the present study were much lower than those of previous studies. The average annual effective dose (AED) of radiation from indoor radon exposure was estimated to be between 0.043 and 0.242 mSv/yr, depending on facility types. These AEDs were substantially lower than the worldwide average AED (2.4 mSv/yr).

• 한국산업보건학회지
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• 제28권4호
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• pp.382-392
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• 2018

Objective: Allergic diseases such as asthma due to fungal exposure in houses have increased, and proper management is urgent. Mold can grow in the air, floor, walls, and other areas according to environmental conditions, and there are many limitations to the conventional methodology for examining fungal exposure. For this reason, the degree of fungal contamination is being evaluated by ERMI (Environmental Relative Moldiness Index), a quantitative analysis method proposed by the EPA. In this study, we compared ERMI values between water-damaged dwellings and non-damaged ones to evaluate the effectiveness of Korean ERMI values. We also explored the association of ERMI values with the level of airborne mold and characteristics of dwellings. Methods: Floor dust was collected after installing a Dustream collector on the suction port of a vacuum cleaner. The collected samples were filtered to remove only 5 mg of dust, and DNA was extracted using the FastDNA SPIN KIT protocol. Results: The ERMI values were found to be 19.6 (-6.9-58.8) for flooded houses, 7.5 (-29.2-48.3) for leaks/condensation, and 0.8 (-29.2-37.9) for non-damaged dwellings. The airborne concentration of mold for flooded, leakage or condensed, and non-damaged houses were $684CFU/m^3$, $566CFU/m^3$, and $378CFU/m^3$, respectively. The correlation between ERMI values and the levels of airborne mold was low (R = 0.038), but a weakly significant association of the ERMI values with the concentration of particulate matter ($PM_{10}$) was observed as well(R=0.231,P<0.05). Conclusions: Our findings show that the reference value using ERMI can be used to distinguish water-damaged and non-damaged dwellings. It is believed that ERMI values could be a promising tool for assessing long-term fungal exposure in dwellings.

• Mycobiology
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• 제51권5호
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• pp.343-353
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• 2023

Lichens play crucial roles in the ecosystems, contributing to soil formation and nutrient cycling, and being used in biomonitoring efforts to assess the sustainability of ecosystems including air quality. Previous studies on heavy metal accumulation in lichens have mostly relied on manipulated environments, such as transplanted lichens, leaving us with a dearth of research on how lichens physiologically respond to heavy metal exposure in their natural habitats. To fill this knowledge gap, we investigated lichens from two of South Korea's geographically distant regions, Gangwon Province and Jeju Island, and examined whether difference in ambient heavy metal concentrations could be detected through physiological variables, including chlorophyll damage, lipid oxidation, and protein content. The physiological variables of lichens in response to heavy metals differed according to the collection area: Arsenic exerted a significant impact on chlorophyll degradation and protein content. The degree of fatty acid oxidation in lichens was associated with increased Cu concentrations. Our research highlights the value of lichens as a bioindicator, as we found that even small variations in ambient heavy metal concentrations can be detected in natural lichens. Furthermore, our study sheds light on which physiology variables that can be used as indicators of specific heavy metals, underscoring the potential of lichens for future ecology studies.

• 폴리머
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• 제36권1호
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• pp.65-70
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• 2012

글리시딜메타크릴레이트(GMA)의 플라즈마 유도 그래프트 공중합을 통해 기재로 사용한 평판형 폴리프로필렌 위에 에폭시 그룹을 도입하였다. 그래프트 공중합은 에멀젼 공중합법을 적용하였고, 기존의 용액 공중합과 비교하여 그 효과를 확인하고자 하였다. 대기압 플라즈마 처리 조건은 RF power 200 W, 처리시간 30초, Ar 기체 유속 6 LPM으로 고정하였고, 처리 후의 대기 중 노출시간 역시 5분으로 고정하였다. 중합반응에서는 GMA의 농도, 반응온도, 반응시간에 따라 표면 그래프트도의 변화를 최적화하였다. 그 결과, GMA 농도 12%, 반응온도 $90^{\circ}C$, 반응시간 5시간으로 중합하였을 때 가장 높은 그래프트도를 나타내었다. 분석 결과, 같은 반응조건 하에서 에멀젼 중합이 용액 중합에 비하여 더 많은 에폭시 그롭 도입에 효과적임을 확인하였다.

• Tuberculosis and Respiratory Diseases
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• 제59권4호
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• pp.397-405
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• 2005

배 경 : Laminin은 생체조직의 세포외기질에 함유되어 있는 당단백질로 특히 기저막내에 특이적으로 분포되어 있다. 저자들은 군중집회 해산용으로 혹은 군사용으로 널리 사용되고 있는 CS 가스(ortho-chlorobenzylidine malononitrile)가 폭로되었을 때 흰쥐의 폐조직내 laminin에 미치는 영향을 밝히고자 하였다. 대상 및 방법 : 본 실험에 사용한 실험동물은 청정동물실에서 사육한 생후 21일령의 흰쥐 (Sprague-Dawley계) 35마리를 사용하였다. 실험동물은 대조군에 5마리, 실험군에 30마리를 배정하였다. CS 가스에 폭로 후 흰쥐를 12시간, 1일, 2일, 3일, 5일 및 7일 경과후 희생시켜 폐장을 절취하여 면역조직염색 및 면역도금법을 시행하였다. 결 과 : 상기와 같이 조직면역반응과 염색을 시행한 후 조직을 관찰하여 다음과 같은 결과를 얻었다. CS 가스 투여후 2일 경과군의 흰쥐 폐포막에는 림파구, 단핵구등이 침투되기 시작하여 3일 경과군에서는 강도의 염증조직이 관찰되었다. 대조군과 CS 가스 투여 12시간군의 폐장의 제2형폐포세포내에 금과립은 층상체주위와 외형질에서 소수 관찰되었다. 결 론 : 이상과 같은 결과로 흰쥐에 CS 가스를 계속 3일간 투여했을 경우 폐포에서 염증조 직이 형성되고 이때 기저막내 laminin의 분포는 일시 감소되나 염증조직의 소멸과 함께 다시 증가되는 것을 보아 laminin이 조직재형성에의 역할이 흰쥐 폐포에서도 일어나고 있음을 알 수 있었고, 면역금과립방법을 이용한 전자현미경 검사에서 제2형폐포세포내 laminin의 분포도 증명할 수 있었다.

• 한국산업보건학회지
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• 제3권1호
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• pp.78-90
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• 1993

구리 분진에 과다 폭로되는 작업자를 조기 발견하고 생물학적 폭로지수를 제시하고자, 폭로군으로 야금 작업장에서 62명의 담성 작업자를 선정하였다. 구리에 폭로되는 작업자의 개인폭로농도를 평가하기 위해 개인, 공기 시표표집방법을 이용했다. 폭로군에서 생물학적 폭로는 원자흡광광도계를 이용하여 혈액과 요중의 구리농도로 평가하였다. 대조군으로는 직업적으로 구리에 폭로된 기왕력이 없는 성인 남성 70명을 선정하였다. 폭로군의 혈액에서 구리의 평균 농도는 $49.44{\pm}8.90{\mu}g/dl$이었고, 요에서 구리의 평균농도는 $39.99{\pm}11.04{\mu}g/l$이었다. 공기중 구리의 평균농도는 $0.48{\pm}0.31mg/m^3$이었다. 대조군의 혈액에서 구리의 평균농도는$42.93{\pm}5.84{\mu}g/dl$이었고, 요에서 구리의 평균농도는$33.02{\pm}13.38{\mu}g/dl$이었다. 폭로군과 대조군의 혈중 및 요중 구리의 평균농도사이에는 모두 유의한 차이가 있었다. 양군에서 연령과 혈중 구리 농도 및 요중 구리의 농도 사이에는 모두 상관관계가 없었다. 폭로군의 혈중 구리와 요중 구리의 농도사이에는 상관관계가 있었고(r=0.62), 대조군의 혈중 구리농도와 요중 구리의 농도사이에는 상관관계가 있었다(r=0.39). 근속연수에 따른 혈중 및 요중 구리의 평균농도사이에는 모두 유의한 차이가 없었으며, 근속연수와 혈중 및 요중 구리농도사이에는 모두 상관관계가 없었다. 작업공정에 다른 공기중 구리평균농도사이에는 유의한 차이가 있었으나, 혈중 및 요중 구려평균농도사이에는 유의한 차이가 있었으며, 공기중 구리의 개인폭로농도와 혈중 구리농도 및 요중 구리농도 사이에는 모두 상관관계가 있었다(혈중 구리, r=0.54 요중 구리, r=0.37).

• 환경위생공학
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• 제18권3호통권49호
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• pp.100-109
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• 2003

Recently, Indoor air quality(IAQ) in workplace, residential environments and schools has been concern of people, scientists and related the public. And so in Seoul has recognized the healthy effect related to IAQ in schools. Therefore, the objective of this study reported in this article were to measure and compare the perception of IAQ of selected air pollutants at three different schools in Seoul. We performed a questionnaire survey of 400 students about their awareness for the importance of IAQ in our school. And we measured the IAQ of 3 schools considering as site region, construction year and studying level. The indoor air pollutants and parameters such as temperature, relative humidity, respirable particulate matter(PM10), formaldehyde(HCHO), total bacteria counts(TBC), carbon dioxide(CO$_2$), and noise were monitored in indoors. In results, all most response of occupant has recognized the awareness of IAQ at schools. The PMIO, TBC and Noise level of all schools were higher than the standard of the public 150 ${mu}$g/m$^3$ and 500CFU/m$^3$, the level formaldehyde(HCHO) was below 0.1 ppm of the healthy guideline of Korea And the concentration of CO$_2$ were investigated below 1,000 ppm of the standard implying ventilation in 2 schools except for 1 school(c school). Finally, the control of most important pollutants of IAQ in school were PM10, TBC and Noise. Therefore, it can be concluded that the indoor air quality of selected 3 schools studied was perceived as acceptable, it is recommended that the government related IAQ was suggested the guideline and control of IAQ problems in schools, and all member relating school need to be effort to reduce the exposure of sources to undesirable indoor pollutants such as Particlate and Noise.

• 한국입자에어로졸학회지
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• 제15권4호
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• pp.191-202
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• 2019

In this study, performance (particle removal efficiency and breathing resistance) of several commercially available face masks (electrostatic filter masks (KF80 certified), a nanofiber filter mask (KF80 certified), and an uncertified mask) with their filter structure and composition were evaluated. Also, effects of relative humidity (RH) of incoming air, water and alcohol exposure, and reusability on performance of face masks were examined. Monodisperse and polydisperse sodium chloride particles were used as test aerosols. Except the uncertified mask filter, PM_2.5 removal efficiency was found to be higher than 90%, and the nanofiber filter mask had the highest quality factor due to the low pressure drop and high removal efficiency (nanofibers were arranged in a densely packed pore structure and contained a significant amount of fluorine in addition to carbon and oxygen). In the case of the KF80 certified mask, the removal efficiency was little affected when the RH of incoming air increased. When the mask filters were soaked in water, the removal efficiency of mask filters was degraded. In particular, the uncertified mask filter showed the highest removal efficiency degradation (26%). When the mask was soaked in alcohol, the removal efficiency also decreased with the greater degree than the water soaking case. The nanofiber mask filter showed the strongest resistance to alcohol exposure among tested mask filters. During evaluation of reusability of masks in real life, the removal efficiency of certified mask filter was less than 4% for 5 consecutive days (2 hours per day), while the removal efficiency of uncertified mask filter significantly decreased by 30% after 5 days.

• Toxicological Research
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• 제26권1호
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• pp.21-28
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• 2010

As the frequency and the intensity of so called Asian dust (AD) events have increased, public concerns about the adverse health effects has spiked sharply over the last two decades. Despite the recent reports on the correlation between AD events and the risk for cardiovascular and respiratory disease, the nature of the toxicity and the degree of the risk are yet largely unknown. In the present study, we investigated the effects of the dichloromethane extract of AD (AD-X) and that of urban dust (NAD-X) collected during a non-AD period on gene expression in HL-60 cells using Illumina Sentrix HumanRef-8 Expression BeadChips. Global changes in gene expression were analyzed after 24 h of incubation with 50 or 100 ${\mu}g$/ml AD-X and NAD-X. By one-way analysis of variance (p < 0.05) and Benjamini-Hochberg multiple testing correction for false discovery rate of the results, 573 and 297 genes were identified as AD-X- and NAD-X-responsive, respectively. The genes were classified into three groups by Venn diagram analysis of their expression profile, i.e., 290 AD-X-specific, 14 NAD-X-specific, and 283 overlapping genes. Quantitative realtime PCR confirmed the changes in the expression levels of the selected genes. The expression patterns of five genes, namely SORL1, RABEPK, DDIT4, AZU1, and NUDT1 differed significantly between the two groups. Following rigorous validation process, these genes may provide information in developing biomarker for AD exposure.

• 한국환경보건학회지
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• 제26권2호
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• pp.97-107
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• 2000

PCBs [Polychlorinated biphenyls] are halogenated aromatic compounds with the empirical formula C12H10-nCln(n=1~10), and are a mixture of possible 209 different chlorinated congeners. PCBs were widely used as dielectric fluids for capacitors, transformers, plasticizers, lubricant inks, and paint additives. once released into the environment, PCBs persist for years because they are so resistant to degradation. In addition to their high degree of lipophilicity. In 1970s, the worldwide production of PCBs seem to be still in use. The environmental load of PCBs was prohibited since 1983 in Korea. In spite of these actions, many PCBs seem to be still in use. The environmental load of PCBs will continue to be recycled through air, land, water, and the biosphere for decades to come. This study was conducted to measure the concentrations of PCBs I the serum samples of 112 women by GC/MSD(Hewlett Packard 5897 Gas Chromatography-Mass Chromatography Detector) and CG/ECD(Hewlett Packard 5890 series-II gas chromatography-Electron capture detector, U.S.A). The main results of this study were as follows; The mean and standard deviation of serum PCBs were 3.613, 0.759 ppb, respectively and median of it was 3.828 ppb. The correlation coefficients of the concentrations of 13 PCB congeners ranged from 0.7913 to 0..9985 and were significantly correlated between each items(p=0.0001). The PCB concentrations were positively associated with age(simple linear regression; R2=0.86, =0.08023, p<0.001) and with total lipids in serums(simple linear regression; R=0.7058, =0.00486, p<0.001). The age adjusted model (Y=$\beta$0+$\beta$1age+$\beta$2X) was applied for possible predictors of PCBs levels in serum. For BMI(Body Mass Index), major residential area, and fish, meat, and dairy consumption, there was no association with PCBs levels, Also there was negative association for the number of pregnancy and lactation period with PCBs levels.