• Journal of Preventive Medicine and Public Health
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• 제33권2호
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• pp.174-183
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• 2000

울산시에서 대기 오염 정도가 서로 다른 석유화학공단 인근지역의 초등학생들과 교외지역의 초등학생들을 대상으로 1999년 4월 14일부터 20일까지 공단지역의 A초등학생 51명(남자 27명, 여자 24명), B초등학생 99명(남자 49명, 여자 50명) 및 교외지역의 C초등학생 100명(남자53명, 여자 47명)을 대상으로 의한 호흡기계 증상 유병률 등을 파악하는 설문조사, 폐기능 검사, 흉부 방사선 검사 등을 조사하였으며 그 결과는 다음과 같다. 1. 호흡기계 증상 유병률 조사에서 석유화학공단 인근 A초등학생과 B초등학생은 교외지역의 C초등학생에 비하여 '만성기침', '운동시 호흡곤란' 같은 호흡기계 증상 유병률이 높았다. 2. 조사 초등학생의 폐기능 검사는 연령, 성별로 구분한 다음 폐기능에 영향을 주는 신장, 체중 등의 공변인을 조정 후 비교한 결과 공단지역의 11세 A초등학생과 B초등학생은 교외지역의 C초등학생에 비하여 FVC 및 FEV1이 낮았다. 이상과 같은 결과로 볼 때 공단지역에 거주하는 어린이는 대기오염 등 환경적요인에 호흡기계증상 유병률, 폐기능 등에 영향을 받은 것으로 추정되며 장기적으로 공단지 역에 거주하는 초등학생들에 대하여 호흡기계증상 유병률, 폐기능 검사 등을 주기적으로 전향적 연구가 필요한 것으로 생각되며 또한 호흡기질환의 발생률 및 유병률 등을 면밀히 관찰하는 추가적 연구도 필요한 것으로 사료된다.

• 한국산업보건학회지
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• 제3권2호
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• pp.152-165
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• 1993

This study was performed at eleven small-sized plating factories located in Seoul, Incheon, Ansan, and Taejeon from July 21 to October 6, 1992. The major objectives of this study were to evaluate worker exposure to hexavalent chromium and local exhaust ventilation (L.E.V.) systems at the chromium plating operations. The most suitable L.E.V. systems for chromium plating tanks were designed as examples for recommendation to the industry. The results are summarized as follows. The range of chromium plating operations investigated included decorative, hard, and black chromium plating on several kinds of parts. Most of plating tanks were not equipped with proper control methods against emission of hexavalent chromium mists and workers were not wearing appropriate personal protectives. The ariborne hexavalent chromium concentrations showed an approximate lognormal distribution. The geometric means of both personal and area samples were within the Korean and ACGIH standards, $50{\mu}g/m^3$. However, in comparison with the NIOSH criterion, $1{\mu}g/m^3$, the geometric means of personal samples at two factories and the geometric means of area samples at two factories exceeded it. The geometric means of personal and area samples of high exposure groups (above the NIOSH criterion) were 7 and 27 times higher than those of low exposure groups (below the NIOSH criterion), respectively. The L.E.V. systems of high exposure groups were improperly designed, and the factory with the highest exposure level had no L.E.V. systems at all on chemical etching process. Whereas at factories of low exposure groups, mist control methods such as mist suppressants, tank cover, and/or auxillary L.E.V. systems were added to L.E.V systems. The evaluation of L.E.V. systems showed that there was no chromium plating operation satisfying the ACGIH criteria for capture velocity, slot velocity, and exhaust rate simultaneously. To increase performance of L.E.V. systems, it must be designed to minimize the impact of boundary layer separation. Push-pull ventilation hood and downward plenum ventilation hood were suggested for the Korean industry.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 춘계학술발표회
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• pp.207-212
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• 2006

선박에서 선내 소음이 문제로 인식되기 시작한 시기는 1970년대 초반 유럽에서 선박소음규제를 명문화하기 시작한 때로서 이 후 1982년 국제해사기구 (IMO) 에서 "International Code on Noise Levels on Board Ships"가 채택되어 오늘날에는 거의 모든 신조 선박에 대하여 해당하는 조항의 적용이 명문화되었다. 특히, 대형의 디젤기관과 다수의 보조기계가 통시에 운전되어지는 기관실 내부는 크고 복잡한 소음이 발생하는 환경으로 되어지고, 이러한 환경에서 작업하는 작업자는 소음성난청으로 되기 쉽다. 최근에는 각 나라별로 직업상의 난청으로부터 작업자를 보호할 목적으로 허용소음 폭로 시간을 법적으로 규제하고 있다. 우리나라에서는 근로기준법에서 정의하고 있지만 선박의 기관실과 같이 특수한 조건에 대해서 국제해사기구의 규정에 따르고 있다. 본 논문에서는 국내 서남 연안을 정 기적으로 운항하고 있는 저속의 화객선에 대한 소음의 정도를 조사하였다.

• 한국산업보건학회지
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• 제3권2호
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• pp.166-176
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• 1993

In order to investingate the renal dysfunction in workers exposed to aromatic organic solvents, 105 male exposed workers and 109 controls were participated in this study. This study was conducted to examine the correlation among the concentration of aromatic organic solvents in air, worker's urinary NAG activity and urinary hippuric acid. The results were as follows : 1. The exposure level of aromatic organic solvent mixture caculated by the equation proposed by ACGIH was ranged from 0.27 to 0.54 and toluene concentration was ranged from 18.3ppm to 48.3ppm. 2. NAG activity in the urine of control and exposed group were $36.1{\pm}14.2nmolMU/mg$ creatinine and $52.4{\pm}26.1nmolMU/mg$ creatinine, respectively. Hippuric acid concentration in the urine of control and exposed group were $191.1{\pm}194.2mg/g$ creatinine and $789.3{\pm}784.1mg/g$ creatinine, respectively. 3. Correlation coefficent between the exposure level of aromatic organic solvent mixture was significantly related to urinary NAG activity(r=0.542) and urinary hippuric acid(r=0.752). 4. Correlation coefficient between NAG activity and hippuric acid concentration was 0.357. This study suggested that urinary NAG activity was a good renal function index for aromatic organic solvents exposure and urinary hippuric acid was an index for the biological monitoring of toluene exposure.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.178-185
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• 2012

In Korea, researches on the exposure assessment of the hand-transmitted vibration started from the mid-90, however, they were performed in the limited industries such as auto-assembly plants and the evaluation of the vibration was mostly conducted by ISO 5349(1986). Therefore, it was necessary to assess hand-transmitted vibration levels of workplace such as ship building/repairing industry or mining industry where occupational injuries are largely occurred and to evaluate the vibration levels using revised ISO 5349(2001). The SVAN 949 Four Channels Sound & Vibration Analyser was used for the measurement. The workers using a chain saw were exposed to $1.7{\sim}2.8m/s^2$ of daily vibration level. Workers using a rock drill in a coal mining were exposed to the highest vibration acceleration among workers and the levels were $7.1{\sim}10.8m/s^2$. Vibration levels of grinders were different according to the types of grinders. The hand-transmitted vibration of 3 types of grinders were measured and the levels were $3.3{\sim}11.1m/s^2$. Workers using a impact wrench were exposed to $1.5{\sim}1.6m/s^2$ of vibration. Out of 20 kinds of machines, only 4 tools provided the information of vibration acceleration on the instructions. In addition, the current condition of workplaces to control vibration was not much different from the past because there are no vibration exposure limit.

• Journal of Preventive Medicine and Public Health
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• 제37권4호
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• pp.321-328
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• 2004

Objectives : The purpose of this study was to investigate the effect of genetic polymorphism of cytochrome P450 2E1 (CYP2E1) and aldehyde dehydrogenase 2 (ALDH2) on the xylene metabolism. Methods : Among 247 workers, 116 were occupationally exposed to xylene and 131 were not. Workers exposed to xylene had different work such as spray, touch-up, mix & assist, and pre-treat. Questionnaire variables were age, sex, use of personal protective equipment, smoking, previous night's drinking and work duration. The urinary methylhippuric acid was measured in the urine collected in the afternoon and corrected by urinary creatinine concentration. The genotypes of CYP2E1 and ALDH2 were investigated by using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) methods with DNA extracted from venous blood. Results : 1. The urinary concentrations of o-, m-, and p-methylhippuric acid and total methylhippuric acid in the exposed group were significantly higher than those in the non-exposed group (p<0.001). 2. In multiple regression analysis, the urinary methylhippuric acid concentration was significantly influenced by exposure grade (Job-exposure matrixes), smoking, drug use and kind of protective equipment (p<0.1). 3. Genetic polymorphism of CYP2E1 and ALDH2 did not affect urinary methylhippuric acid level in the exposed group (p>0.05). Conclusions : Exposure grade, smoking, drug use and kind of protective equipment affected urinary methylhippuric acid level, whereas genetic polymorphism of CYP2E1 and ALDH2 did not. However, further investigation for the effect of genetic polymorphism on the metabolism of xylene with a larger sample size is needed.

• 한국환경보건학회지
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• 제26권4호
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• pp.21-28
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• 2000

Various man-made mineral fibers(MMMF) including refractory ceramic fiber(RCF) have been used widely in industries as insulation materials. The effect of fibrous dust on human health depends on fiber size, concentration (exposure level), and durability in biological system. Therefore, these parameters should be determined to evaluate accurately the potential risk of fibers on human health. The purpose of this study was to characterize the size of airborne fiber and the workers＇ exposure to airborne fibers in refractory ceramic fiber manufacturing and processing factories. Airborne fibers were collected on 25-mm mixed cellulose ester membrane filters at personal breathing zones, and analyzed by A and B counting rules of the National Institute for Occupational Safety and Health(NIOSH) Method # 7400. The average ratios of the fiber density by B rule to the fiber density by A rule was 0.84. This result indicates that the proportion of respirable fibers (<3 ${\mu}{\textrm}{m}$ diameter) in air samples was high. The average diameter and length of airborne fibers were 1.05${\mu}{\textrm}{m}$ and 35${\mu}{\textrm}{m}$, respectively. The average fiber concentrations (GM) of all personal samples was 0.26f/cc, and the average concentration was highest at blanket cutting and packing processes. The fifty seven percent of personal air samples was exceeded the proposed American Conference of Governmental Industrial Hygienists(ACGIH) Threshold Limit Value(TLV), i.e. 0.2 f/cc. It was concluded that the RCF industrial workers had the higher potential health risk due to small fiber diameter, long fiber length, and high exposure level to the airborne fibers.

• 한국환경보건학회지
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• 제49권2호
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• pp.78-88
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• 2023

Background: Exposure to volatile organic compounds (VOCs) can have acute and chronic health effects on human beings in general and in working environments. In particular, VOCs are often emitted in large quantities in industrial settings. In such circumstances, there is a need to improve the indoor air quality at workplaces. Objectives: The purposes of this study were to verify the effectiveness of air cleaning devices in workplaces and provide alternative solutions for improving working environments. Methods: Personal exposure and area level of VOCs for workers were evaluated in a car-part adhesive process before and after installing an air cleaning device with a TiO₂-coated filter. Passive samplers and direct reading instruments were used to collect and analyze the VOCs, and the removal efficiency and improvement of air quality were evaluated. We also calculated the exposure index (EI) to assess the risk level in the workplace. Results: The removal efficiency for VOCs through the installation of the air cleaning device was approximately 26.9~69.0% as determined by the concentration levels before and after installation. The measured substances did not exceed the exposure limits for the work environment and the EI was less than 1. However, carcinogenic substances such as benzene, formaldehyde, carbon tetrachloride, and trichloroethylene were detected. Conclusions: The application of an air cleaning device can be a solution for controlling the indoor air quality in a workplace, particularly in cases where ventilation systems cannot be installed due to process limitations.

• 한국환경보건학회지
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• 제44권5호
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• pp.480-490
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• 2018

Objective: This study aimed to report the level of extremely low frequency-magnetic field (ELF-MF) emitted by portable hand-held fans (HHF) and to discuss the methodologies for determining the health risk of ELF-MF for HHF products. Method: ELF-MF was monitored at eight locations by distances in the vicinity of HHFs. A total of 13 HHF brands on the market were randomly selected. A portable ELF-MF monitor MDEX II was used to measure the ELF-MF level in the range of 40-800 Hz with a resolution of $0.01{\mu}T$. This study also examined the frequency results of a total of 45 HHF products investigated by the Korean Ministry of Science and ICT (KMSICT). Results: ELF-MF higher than $0.3{\mu}T$ was found to be emitted at a distance of less than 20 cm from 12 HHF. ELF-MF emitted from four products was found to exceed the reference level ($83.3{\mu}T$ based on 60 Hz) recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). KMSIT reported that the principle frequency emitted from the HHFs ranged from 54 Hz to 284 kHz, without the level of LEF-MF. Unscientifically, the KMSICT used the reference level by ICNIRP as the chronic level and concluded that all HHFs are safe with a basis of 1.2-36.0% less than the reference level. Conclusion: The HHF emitted much higher levels of ELF-MF than $0.3-0.4{\mu}T$, which is regarded as the reference level for childhood leukemia. The risk of HHF should be examined in terms of whether they can be used by the general public, including children and pregnant woman.

• 한국농공학회논문집
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• 제57권4호
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• pp.21-29
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• 2015

Safety of reclaimed wastewater irrigation needs to be evaluated to promote public health. Quantitative microbial and toxic risk assessment was conducted to identify the level of risk for farmland workers who use reclaimed wastewater and groundwater in Jeju island. Microbial risk through inhalation and ingestion exposure was below acceptable level (less than $10^{-3}$) of $7.07{\times}10^{-6}$ for reclaimed wastewater and $9.99{\times}10^{-8}$ for groundwater irrigation worker. Aggregate exposure risk of Ni, As and Cu was most contributable to overall risk in both reclaimed wastewater and groundwater irrigation plot. High cumulative exposure risk was estimated through non-dietary soil ingestion and dermal contact of soil, due to the high concentration of As, Cu and Ni in farmland soil. Overall toxic risk was $2.68{\times}10^{-4}$ for reclaimed water and $2.39{\times}10^{-4}$ for groundwater irrigation, which could not meet acceptable toxic risk level of $10^{-6}$. Further efforts, such as provide personal protective equipments or public health education, need to be implicated to reduce adverse health risk.