• Environmental Analysis Health and Toxicology
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• 제17권3호
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• pp.197-205
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• 2002

Volatile organic compounds (VOCs) are an important public health problem throughout the world. Many important questions remain to be addressed in assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in the analytical determination of VOCs. Personal exposure measurements are needed to evaluate the relationship between microenvironmental concentrations and actual exposures. It is also important to investigate exposure frequency, duration, and intensity, as well as personal exposure characteristics. In addition to air monitoring, biological monitoring may contribute significantly to risk assessment by allowing estimation of absorbed doses, rather than just the external exposure concentrations, which are evaluated by environmental and personal monitoring. This study was conducted to establish the analytic procedure of VOCs in air, blood, urine and exhaled breath and to evaluate the relationships among these environmental media. The subjects of this study were selected because they are occupationally exposed to high levels of VOCs. Environmental, personal, blood, urine and exhalation samples were collected. Purge ＆ trap, thermal desorber, gas chromatography and mass selective detector were used to analyze the collected samples. Analytical procedures were validated with the“break through test”, 'quot;recovery test for storage and transportation”,“method detection limit test”and“inter-laboratory QA/QC study”. Assessment of halogenated compounds indicted that they were significantly correlated to each other (p value < 0.01). In a similar manner, aromatic compounds were also correlated, except in urine sample. Linear regression was used to evaluate the relationships between personal exposures and environmental concentrations. These relationships for aromatic and halogenated are as follows: Halogen $s_{personal}$ = 3.875+0.068Halogen $s_{environmet}$, ($R^2$= .930) Aromatic $s_{personal}$ = 34217.757-31.266Aromatic $s_{environmet}$, ($R^2$= .821) Multiple regression was used to evaluate the relationship between exposures and various exposure deter-minants including, gender, duration of employment, and smoking history. The results of the regression model-ins for halogens in blood and aromatics in urine are as follows: Halogen $s_{blood}$ = 8.181+0.246Halogen $s_{personal}$+3.975Gender ($R^2$= .925), Aromatic $s_{urine}$ = 249.565+0.135Aromatic $s_{personal}$ -5.651 D.S ($R^2$ = .735), In conclusion, we have established analytic procedures for VOC measurement in biological and environmental samples and have presented data demonstrating relationships between VOCs levels in biological media and environmental samples. Abbreviation GC/MS, Gas Chromatography/Mass Spectrometer; VOCs, Volatile Organic Compounds; OVM, Organic Vapor Monitor; TO, Toxic Organicsapor Monitor; TO, Toxic Organics.

• 대한임상검사과학회지
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• 제41권2호
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• pp.67-75
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• 2009

In order to provide basic data for the prevention of adverse effects of lead on health, we examined lead levels in the blood of 30 handicapped workers employed in manufacturing electronic components in Seoul from 2002 to 2008. The average lead level in the blood of all the subjects was $4.79{\pm}4.32{\mu}g/dL$ in females, $2.64{\pm}2.31{\mu}g/dL$ in males, and $3.88{\pm}3.75{\mu}g/dL$ in total. Lead levels examined in this study were significantly lower than other investigators study have reported. The average lead level from personal exposure of the subjects was $1.44{\pm}0.91mg/m^3$ in the workplace. The relation between blood lead levels and personal exposure was a simple linear regression; it's equation was "Lead level in blood = 6.04 - 1.92 lead level by personal exposure".

• Journal of Electrical Engineering and Technology
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• 제7권3호
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• pp.376-383
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• 2012

A number of scientific researches are currently being conducted on the potential health hazards of power frequency electric and magnetic field (EMF). There exists a non-objective and psychological belief that they are harmful, although no scientific and objective proof of such exists. This possible health risk from ELF magnetic field (MF) exposure, especially for children under 17 years of age, is currently one of Korea's most highly contested social issues. Therefore, to assess the magnetic field exposure levels of those children in their general living environments, the personal MF exposure levels of 436 subjects were measured for about 6 years using government funding. Using the measured database, estimation formulas were developed to predict personal MF exposure levels. These formulas can serve as valuable tools in estimating 24-hour personal MF exposure levels without directly measuring the exposure. Three types of estimation formulas were developed by applying evolutionary computation methods such as genetic algorithm (GA) and genetic programming (GP). After tuning the database, the final three formulas with the smallest estimation error were selected, where the target estimation error was approximately 0.03 ${\mu}T$. The seven parameters of each of these three formulas are gender (G), age (A), house type (H), house size (HS), distance between the subject's residence and a power line (RD), power line voltage class (KV), and the usage conditions of electric appliances (RULE).

• 한국환경보건학회지
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• 제23권1호
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• pp.55-61
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• 1997

This study was executed for the purpose of investigation of the EMFs exposures of personal and electronic environment. This study examines ELF-EMFs of electric appliances, subways and occupational and non-occupational human exposures, using EMDEX II (for 40 - 800Hz, Enertech Consultant, Inc.), from October 1995 to March 1996. Among the electric appliances examined, a massage unit showed the highest mean value of 247.07 $\mu$T, followed by an electric blanket of 5.24 $\mu$T. Indoor levels of EMF in subways exceerlcd 0.2 $\mu$T of the Swedish Guideline. The mean personal exposure levels of occupational group were 0.18 $\mu$T, while the personal EMF level of non-occupational group were 0.07 $\mu$T. Occupational group were exposed more highly while at work. However, the EMF levels during nonwork and sleep exposures between occuptional group and nonoccupational group were about the same. Estimates of time-intergrated exposure indicated that utility-specipic job classifications received about one-half or more of their total exposure on the job. Finally, this study would provide significant data for future research for exposure to magnetic fields, and more detailed study and research are necessary.

• 한국산업보건학회지
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• 제22권2호
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• pp.128-133
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• 2012

People are exposed to air pollution from a range of indoor and outdoor sources. Concentration of nitrogen dioxide $(NO_2)$, which is hazardous to health, can be significant in both types of environment. This paper reports on the measurement and analysis of indoor and outdoor $NO_2$ concentrations and their comparison with measured personal exposure in house and workplace indoors with 28 office workers during winter and summer seasons. Time activity patterns were used to determine the effects of these factors on personal exposure. The residential indoor and office indoor times were $12.29{\pm}1.58,$ $7.86{\pm}1.97$ hours in winter and $11.04{\pm}2.18,$ $8.26{\pm}2.04$ hours in summer, respectively. Measured residential indoor, outdoor and office indoor, personal exposure $NO_2$ concentrations were $23.10{\pm}8.46$ ppb, $23.97{\pm}6.86$ ppb, $21.91{\pm}11.50$ ppb, $22.08{\pm}8.64$ ppb in winter, and $19.94{\pm}6.04$ ppb, $21.21{\pm}6.84{\pm}$ ppb, $22.55{\pm}9.54$ ppb, $27.45{\pm}8.96$ ppb in summer, respectively. Contributions of residential and office indoor $NO_2$ concentration on personal exposure were estimated by 57.98%, 35.62% in winter and 37.38%, 28.97% in summer, respectively.

• 한국대기환경학회지
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• 제6권1호
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• pp.97-102
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• 1990

A pilot field study was conducted to measure indoor and personal exposure to carbon monoxide (CO) levels using personal monitors from January to February in 1989. The principal objectives of the study was to design and evaluate the research protocol and the instrumentation performance for application to the conduct of a large-scale personal monitoring program. The mean CO concentrations in kitchen and in bedroom were 23.4 and 11.9 ppm, respectively, while mean concentration of personal CO exposure was 18.9 ppm. It was found that the mean CO concentrations in kitchen exceeded 20 ppm of the Korea ambient CO standard(8-hr average) not to be exceeded more than three times per year. The results suggest that indoor CO levels in Korean houses appear to be affected by use of coal briquette for heating any cooking.

• KIEE International Transactions on Electrophysics and Applications
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• 제12C권4호
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• pp.195-200
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• 2002

The objective of this survey is to characterize personal magnetic field exposure of the general population in Korea. The participants of the survey on magnetic field exposure were selected randomly in some occupations. The participant wore the magnetic field meter for about 25∼28 hours and the data were stored in the meter. Because this is a preliminary for the main survey, it was done with 36 participants only. For the main survey, about 400 subjects by occupation will be done. The statistics of the 24-hour exposure data are the major concern of this survey However the survey provided the opportunity to analyze exposures corresponding to different types of activities. It was analyzed by separating periods of time corresponding to the following activities: entire 24-hour period, in bed, at work and by occupation.

• 한국산업보건학회지
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• 제3권2호
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• pp.227-239
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• 1993

The author selected 77 dust emissing processes from 71 types of industries which placed in Sasang Industrial Complex in Pusan. The level of total dust was measured as areal concentration and personal exposure concentration by low volume air sampler and personal air sampler, respectively. Collected samples were classified into 5 groups (chemicals and rubber product, metal product, sawmills and wood, foundries and others). Respirable particulate and total dust of areal and personal exposure were analyzed. The results were as follows; 1. All of the respirable dust concentration and total dust of areal and personal concentration were log-normally distributed. 2. Geometric mean of respirable particulate of personal exposure concentration measured $0.55mg/m^3$ in the first group, $0.86mg/m^3$ in the second group, $0.39mg/m^3$ in the third group, $0.81mg/m^3$ in the forth group and $0.52mg/m^3$ in the fifith group. The exceed rates over TLV (thehold limit values) of total dust were 31.3% in the first group, 31.3% in the second group, 70% in the third group, 80% in the forth group and 13.3% in the fifth group. 3. There were singnificant difference between areal and personal exposure concentration and personal exposure concentration was higher than that of area. 4. In the case of high ratio of respirable particulate to total dust, pneumoconiosis incidence was high even though the workshop was opened and emissing dust concentration was low. These findings suggest that it is desirable to measure respirable particulate in environmental assessment of dust emissing workshops.

• 한국정보통신학회논문지
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• 제14권5호
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• pp.1085-1092
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• 2010

본 논문에서는 최적화 알고리즘인 PSO를 이용하여 한국인의 생활자계 노출실태 조사 시 확보한 16세 이하의 미취학 아동, 초등학생, 중학생 실측 데이터베이스를 활용하여, 자계노출의 정도를 실측에 의하지 않고 추정할 수 있는 '24시간 소아고노출 생활자계 추정식'을 개발하였다. 24시간 개인자계 노출량 추정식의 입력 데이터는 성, 연령, 주거형태, 주거지 크기, 선로이격거리 및 송전전압을 사용하였다. 그리고 16세 이하에 대해서 24시간 고노출 개인자계 노출분포, 자계노출의 특성, 특정 조건별 자계노출특성 등을 분석하였다.

• 한국환경보건학회지
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• 제36권5호
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• pp.351-359
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• 2010

The objectives of this study were to understand the characteristics of residents in industrial areas and factors affecting exposure to the Volatile Organic Compounds(VOCs : Benzene, Toluene, Xylene) as well as to assess exposure levels according to house-type, and whether residents were indoors or outdoors. This research was designed to assess the differences in exposure levels to indoor, outdoor and personal VOCs in a case group and a control group across all areas, as well as in each different area, from May to October 2007, in. 110 residents of the G, Y and H industrial areas of the Jun-nam province. The geometric mea-levels of airborne benzene for the case group 1.31part per billion(ppb) indoor, 1.29 ppb outdoor, and 1.32 ppb for personal exposure were significantly higher than for the control group 0.99, 0.87 and 0.57 ppb, respectively. The geometric mean level for toluene personal exposure across the G, Y and H areas was 5.70 ppb for the case group and 6.31 ppb for the control group. While the outdoor level was 4.27 ppb for the case group and 5.06 ppb for the control group, The indoor level for the case group was 4.78 ppb, similar to that of the control group 4.69 ppb. The geometric mean levels for airborne xylene across the G, Y and H areas were 0.16 ppb(outdoor), 0.12 ppb(personal exposure) and 0.10 ppb(indoor) for the case group, and for the control group were 0.17(personal exposure) and 0.09 ppb(indoor and outdoor). The indoor/outdoor(I/O) ratio for case group is 1.19, while that of the control group is 1.15, indicating that the indoor level was higher than the outdoor level. The interrelationship differences among the three different types of levels in the air in the G, Y and H areas are statistically significant, except for the difference between the indoor and outdoor figures for xylene. In terms of the different types of houses and energy type uesd, the geometric mean level for airborne benzene, toluene and xylene for houses were 1.61, 5.39 and 0.12 ppb, respectively. while the figures for flats were 0.67, 3.32 and 0.05 ppb, respectively. Outdoors, the levels of benzene and toluene in flats were 0.71 and 2.62 ppb, respectively. and 1.58 and 5.35 ppb in houses. For personal exposure, the house levels of benzene, toluene and xylene were all higher than for flats. Houses using oil for heating have significantly higher levels than flats, which use gas for heating.