경남지역 지하생활공간 중 석면 및 라돈의 농도 분포 특성

하권철 ( Kwon Chul Ha ) 한국산업위생학회 2004 한국산업보건학회지 Vol.14 No.3

The purpose of this research is to characterize airborne asbestos and radon concentrations as trace toxic air pollutant in the underground spaces in Gyungnam province. Air samples of asbestos and radon were taken in the three underground spaces for ten months from April 2003 to January 2004. The IAQ(Indoor Air Quality) of underground spaces were controlled using central ventilation (supply/exhaust) system. The levels of geometric means of airborne asbestos and radon concentrations in three sampling spaces were below the standards of Korean Ministry of Environment. However, one sample of airborne asbestos in underground spaces "C", which was used fire proofing fibrous material, was in excess of the standard. There are significantly statistical differences in levels of trace toxic air pollutants by sampling spaces(p<0.05).

[환경] 실내환경의 환경성담배연기(ETS) 중 카드뮴에 관한 연구

하권철(Kwon Chul Ha),박동욱(Dong-Uk Park),윤충식(Chung Sik Yoon) 한국분석과학회 2003 분석과학 Vol.16 No.4

경남지역 지하생활공간 중 미량 유해물질인 포름알데히드의 농도 분포 특성

하권철,Ha Kwon Chul 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.5

The purpose of this research is to characterize formaldehyde as trace toxic air pollutant in the underground spaces in Gyungnam province. Air samples of formaldehyde were taken in the three underground spaces for ten months from April 2003 to January 2004. The IAQ(Indoor Air Quality) of underground spaces were controled using central ventilation(supply/exhaust) system. The levels of GM of airborne formaldehyde concentrations in three sampling spaces were well below applicable standards, Korean Ministry of Environment, 0.1 ppm. However, some sample of airborne formaldehyde concentrations in underground spaces 'B' and 'C' were in excess of standard, due to the commercial products in shop, structural material, and the climate having high humidity and temperature. There are statistical differences in levels of formaldehyde by sampling spaces (p=0.086).

Effect of Airborne Lead Concentration Characterized by Size on Blood Lead and Their Relationships

박동욱,하권철,Park, Dong-Uk,Ha, Kwon-Chul Korean Society of Environmental Health 2005 한국환경보건학회지 Vol.31 No.4

4개 업종(축전지제조업, 광명단 제조업, 2차 제련업, 라디에타 제조업)에서 근무하는 총 100명의 근로자를 대상으로 8단계다단충돌기(eight stages personal cascade imparter)에 의한 입자 크기 별 납농도를 측정하였다 크기 별 납 농도는 총납(PbA), 흡입성납(IPM-PbA), 흉곽성납(TPM-PbA), 호흡성납(RPM-PbA), $1{\mu}m$ 미만의 납$(Pb_{1\mu})$ 그리고 $1{\mu}m$ 이상의 소화성납$(Pb_{ing})$이었다. 동일한 근로자(100명)를 대상으로 혈액에서 납농도를 측정하였다. 혈액 중 납은 원자흡광광도계(atomic absorption spectrometry)의 Zeeman effect graphite furnace를 이용하여 분석하였다. 총 납의 노출농도는 노출기준$(50\;ug/m^3)$을 크게 초과하였다. 평균 호흡성 납 노출농도$(115.7\;ug/m^3)$ 총 납의 노출기준을 훨씬 초과하였다. $1{\mu}m$미만의 납$(Pb_{1\mu})$ 노출농도의 범위는 0.7에서 $(492.2\;ug/m^3)$이나 되었다. 근로자의 $46\%$가 혈액 중 납 농도 40 ug/dL을 초과하였다. 60 ug/dL을 초과한 경우도 $13\%$나 되었다. 입자 크기가 큰 납인 총납, 흡입성 납 그리고 호흡성 납 농도는 혈액 중 납 농도와 유의한 상관을 보였다(p<0.0001). 그러나 가장 높은 상관은 $1{\mu}m$미만의 납$(Pb_{1\mu})$ 혈액 중 납과의 관계였다. T-test에서 $50ug/m^3$이상의 호흡성 납을 나타낸 근로자 그룹과 $50ug/m^3$ 이하의 근로자 그룹간에의 혈액 중 납 농도는 유의한 차이가 있는 것으로 나타났다(p=0.000). 이러한 연구결과는 입자크기 구분이 없는 현재의 총납에 의한 노출기준과 측정방법은 미세 납 먼지에 노출되는 근로자의 납흡수를 보호하는데 한계점이 있다는 것을 의미한다. 향후 납 입자크기는 물론 근로자의 개인적인 위생과 작업내용 등을 변수로 납 흡수에 영향을 미치는 종합적인 요인을 찾아내는 연구를 진행할 필요가 있다.

Loss of Metalworking Fluids Collected on PVC Filter Due to Contact with Clean Air and Desiccation

박동욱,하권철,Park, Dong-Uk,Ha, Kwon-Chul 한국분석과학회 2001 분석과학 Vol.14 No.5

Because liquids with high molecular weight such as mineral oil have low vapor pressure at room temperature, it is generally thought to be difficult to lose them to evaporation. However, when they are dispersed into air in small droplets during application in machining processes, their surface area becomes considerably higher. To determine the potential for metalworking fluids (MWF) filter losses, MWF mist was generated and collected on polyvinyl chloride (PVC) filters in test chamber. After collected MWF was exposed to clean air during designated period (range 10~240 minutes) and the filters were desiccated, losses were evaluated. As duration of clean air passing through PVC filter increased, loss of MWF gradually increased. MWF lost after 10 minutes ranged form 12.4 % to 21.8 % of the original loading mass, on average 53.3 % of the total loss. These results indicate that significant mass of MWF collected on PVC filters can be lost at the beginning of air sampling. Loss of MWF collected on PVC filter also occurred during desiccation without active airflow. In multiple regression to identify which factors influence the loss of MWF collected on PVC filter, both duration of air passing through PVC filter and MWF age (fresh vs. used) were significant predictor (p=0.0001). Therefore, workers' exposure to MWF measured method 0500, may underestimate true concentration. Further study is needed to develop a new method to quantify the workers' exposure to airborne MWF mist accurately. 절삭유(Metalworking Fludis, MWF) 노출로 인한 건강상의 장애는 암, 호흡기질환, 피부질환이다. MWF는 20여가지 이상의 화학물질이 혼합된 고분자의 화합물로서 상온에서 쉽게 증발되지 않는다. 이러한 특성으로 공기 중 MWF미스트의 측정과 분석은 PVC필터를 이용한 중량법이 국제적으로 공인되어 이용되고 있다. 그러나 사업장에서 MWF는 사용과정에서 분산되면 표면적이 커지고 증발하기 쉬운 상태로 된다. 본 연구는 실험실에서 MWF미스트 발생장치를 제작하여 MWF미스트가 필터에 채취되고 분석되는 과정에서 손실되는 양과 원인을 정량적으로 분석하였다. 즉 챔버에서 MWF가 채취된 PVC필터를 깨끗한 공기로 일정시간동안(10 ~ 240 분) 접촉하고 건조하여 각각의 과정(공기접촉, 건조기간)에서의 손실을 평가하였다. 공기와의 접촉 10분 후에 손실된 MWF양은 원래양의 12.4% - 21.8%였다. 전과정에서 손실된 양의 53.3%가 공기의 접촉초기에 일어나는 것을 확인하였다. PVC필터에 채취된 MWF의 손실은 건조과정에서 일어난 것을 확인하였다. PVC필터에 채취된 MWF의 손실에 영향을 미치는 요인을 분석하기 위한 다중회귀분석에서 MWF의 특성(사용중인 것과 사용하지 않는 것)이 유의한 예측변수였다. 이 연구 결과에 따르면, 국제적으로 공인된 증량법에 의한 공기중 MWF측정은 과소평가되는 것으로 판단된다.

작업환경측정 자료를 활용한 Dichloromethane 노출 매트릭스 구축에 대한 연구

이재환,박동욱,홍성철,하권철,Lee, Jae-Hwan,Park, Dong-Uk,Hong, Sung-Chul,Ha, Kwon-Chul 한국환경보건학회 2010 한국환경보건학회지 Vol.36 No.5

A reduction in risk of occupational exposure to chemical hazards within the workplace has been the focus of attention both through industry initiatives and legislation. The aims of this study were to develop an exposure matrix by industry and process, and to apply this matrix to control the risk of occupational exposure to Dichloromethane (DCM). The exposure matrix is a tool to convert information on industry and process into information on occupational risk. The exposure matrix comprised industries and processes involving DCM, based on an exposure database provided by KOSHA (the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. The risk assessment of the exposure matrix was performed using Hallmark risk assessment tool. The results of the risk assessment were indicated by a Danger Value (DV) calculated from the combination of hazard rating (HR), duration of use rating (DUR), and risk probability rating (RPR) of exposure to the chemical, and were divided into four control bands which were related to control measures. The applicability of the risk assessment of the exposure matrix was evaluated by a field study, and survey of the employees of the exposure matrix groups. Among 45 industries examined, this study found that greater attention should be paid to two industries: the manufacture of other optical instruments and photographic equipment, and the manufacture of printing ink, and to one process among 47 examined, the packing process in the manufacture of printing ink, because these were regarded as carrying the highest risk. This tool of a risk assessment for the exposure matrix can be applied as a general exposure information system for hazard control, risk quantification, setting the occupational exposure limit, and hazard surveillance. The exposure matrix includes workforce data, and it provides information on the numbers of exposed workers in Korea by agent, occupation, and level of exposure and risk.

산업안전보건교육이 산업재해발생에 미치는 영향에 관한 연구

장공화 ( Kong Hwa Jang ),하권철 ( Kwon Chul Ha ) 한국산업보건학회 2016 한국산업보건학회지 Vol.26 No.1

Objectives: The aim of this study is to analyze the status of implementation of occupational safety and health education and evaluate the relation between the implementation of education and occupational accidents. Methods: This study used data on occupational safety and health education from the 2012 Current Status of Occupational Safety and Health survey by the Korea Occupational Safety and Health Agency. The sample is 7,010 persons working in relation to occupational safety and health in industry. An ANOVA test is used to analyze the status of and need for education. Poisson regression is used to evaluate the relation between education and occupational accidents. Results: The rate of implementation of education is 53.3% for periodic education on workers holding office positions, 68.3% for periodic education for workers not holding office positions, 60.3% for periodic education for persons holding managerial and supervisory positions, 65.5% for education provided upon hiring, 50.5% for education provided upon changes in work activities and 37.2% for special education. In the Poisson regression, these data strongly suggest that the probability of occupational accidents occurring with education implemented is much lower than without the implementation of any kind of safety and health education. Conclusions: It is clear that implementation of education has a positive effect on reducing occupational accidents, although its application in domestic industry is insufficient. Thus, it is concluded that education on occupational safety and health should be strengthened for the prevention of occupational accidents.

창원시 학동 전기 소아들의 아토피 피부염 유병률과 그 원인에 관한 연구

이종근,이호성,하진실,박동진,백도현,하권철,Lee, Jong-Keun,Lee, Ho-Sung,Ha, Jin-Sil,Park, Dong-Jin,Paik, Do-Hyun,Ha, Kwon-Chul 한국환경보건학회 2009 한국환경보건학회지 Vol.35 No.3

In the past decade there has been increasing concern about the atopic dermatitis (AD) associated with environmental diseases. AD has been increased in the last decade and known as one of the multifactoral diseases, which has the genetic background and environmental factors at the same time. The purposes of this study were to investigate the prevalence rate and etiologic risk factors of atopic dermatitis in preschool children in Changwon, which is a one of the Korean cities and has a large industrial complex. We reviewed and analyzed the statistical data, obtained from Korea National Health Insurance Corporation, related to prevalence rate by age and administrative district. A cross-sectional questionnaire survey, based on ISAAC (International Study of Allergy and Asthma in Childhood), was conducted on random samples of preschool children (5 to 8 years old) of large sized kindergartens in Changwon. The lifetime and last one years prevalence of AD in preschool children in Changwon was increased from 1998 to 2008. The prevalence rate of AD in the preschool children in Changwon city was 9.6%. The prevalence rate in boys was 9.7% and that in girls was 9.4%. The one year prevalence of AD was ranked as middle among other provincial cities in Korea in 2008. This study showed that the prevalence rate of the atopic disease in Changwon was 9% in 2008, which was increased especially compare to 2000. More active governmental approaches for control and prevention of atopic dermatitis for children are recommended. Further studies are needed for more accurate estimation of the prevalence of AD in Korea including different regional and age population.

비 포괄적인 금연정책을 시행한 호프집의 면적에 따른 실내 PM_2.5 농도

김정훈,임채윤,이대엽,김혜진,곽수영,이나은,김상환,하권철,이기영,Kim, Jeonghoon,Lim, Chaeyun,Lee, Daeyeop,Kim, Heyjin,Guak, Sooyoung,Lee, Na Eun,Kim, Sang Hwan,Ha, Kwon Chul,Lee, Kiyoung 한국환경보건학회 2015 한국환경보건학회지 Vol.41 No.2

Objectives: The Korean government implemented a smoke-free regulation for pubs with a net indoor area of ${\geq}100m^2$ on January 1, 2014. The purpose of this study was to determine the indoor levels of concentrations of particulate matter smaller than $2.5{\mu}m$ ($PM_{2.5}$) in implemented and non-implemented pubs in Seoul and Changwon. Methods: $PM_{2.5}$ concentrations in fifty-two $100-150m^2$ (implemented) and fifty-seven < $100m^2$ (non-implemented) pubs were measured. A real-time aerosol monitor was used to measure $PM_{2.5}$ concentrations. Field technicians recorded characteristics of the pubs including net indoor area, indoor volume and presence of smoking rooms and counted the number of burning cigarettes, patrons and vents. Results: Differences between indoor and outdoor $PM_{2.5}$ concentrations in $100-150m^2$ and < $100m^2$ pubs were not significantly different in each city. Smoking was observed in 33% of $100-150m^2$ pubs and 51% of < $100m^2$ pubs. Average differences between indoor and outdoor $PM_{2.5}$ concentrations in the $100-150m^2$ and < $100m^2$ pubs were $79.2{\mu}g/m^3$ and $155.6{\mu}g/m^3$, respectively. When smokers were not observed, differences between indoor and outdoor $PM_{2.5}$ concentrations ware $12.4{\mu}g/m^3$ in $100-150m^2$ pubs and $24.5{\mu}g/m^3$ in < $100m^2$ pubs. Conclusion: Although the regulation was implemented only in ${\geq}100m^2$ pubs, a higher difference between indoor and outdoor $PM_{2.5}$ concentrations was observed in implemented and non-implemented pubs with smokers. Strict implementation of the regulation in all pubs is needed for better indoor air quality.

초등학생 가정을 대상으로 한 바이오에어로졸 노출과 아토피와의 연관성 평가

하진실,정혜정,변혜정,윤충식,김양호,오인보,이지호,하권철,Ha, Jin-Sil,Jung, Hea-Jung,Byun, Hyae-Jeong,Yoon, Chung-Sik,Kim, Yang-Ho,Oh, In-Bo,Lee, Ji-Ho,Ha, Kwon-Chul 한국환경보건학회 2011 한국환경보건학회지 Vol.37 No.6

Objectives: Exposure to bioaerosols in the indoor environment could be associated with a variety adverse health effects, including allergic disease such atopy. The objectives of this study were to assess children's exposure to bioaerosol in home indoor environments and to evaluate the association between atopy and bioaerosol, environmental, and social factors in Ulsan, Korea. Methods: Samples of viable airborne bacteria and fungi were collected by impaction onto agar plates using a Quick Take TM 30 and were counted as colony forming units per cubic meter of air (CFU/$m^3$). Bioaerosols were identified using standard microbial techniques by differential stains and/or microscopy. The environmental factors and possible causes of atopy based on ISAAC (International Study of Allergy and Asthma in Childhood) were collected by questionnaire. Results: The bioaerosol concentrations in indoor environments showed log-normal distribution (p < 0.01). Geometric mean (GM) and geometric standard deviation (GSD) of airborne bacteria and fungi in homes were 189.0 (2.5), 346.1(2.0) CFU/$m^3$, respectively. Indoor fungal levels were significantly higher than those of bacteria (p < 0.001). The concentration of airborne bacteria exceeded the limit recommended by the Korean Ministry of Environment, 800 CFU/$m^3$, in three out of 92 samples (3.3%) from 52 homes. The means of indoor to outdoor ratio (I/O) for airborne bacteria and fungi were 8.15 and 1.13, respectively. The source of airborne bacteria was not outdoors but indoors. GM of airborne bacteria and fungi were 217.6, 291.8 CFU/$m^3$ in the case's home and 162.0, 415.2 CFU/$m^3$ in the control's home respectively. The difference in fungal distributions between case and control were significant (p = 0.004) and the odds ratio was 0.996 (p = 0.027). Atopy was significantly associated with type of house (odds ratio = 1.723, p = 0.047) and income (odds ratio = 1.891, p = 0.041). Some of the potential allergic fungal genera isolated in homes were Cladosporium spp., Botrytis spp., Aspergillus spp., Penicillium spp., and Alternatia spp. Conclusions: These results suggest that there this should be either 'was little' meaning 'basically no significant association was found' or 'was a small negative' mean that an association was found but it was minor. It's a very improtant distinction. Association between airborne fungal concentrations and atopy and certain socioeconomic factors may affect the prevalence of childhood atopy.