• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.142-153
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• 2019

Objectives: The aim of this study was to determine environmental chemical exposure related to residential and personal lifestyle characteristics in the adult Korean population. The observations of this study can provide information useful for developing reduction approaches for exposure to chemicals among the general adult population. Methods: The second stage of the Korean National Environmental Health Survey (KoNHES) was conducted from 2012 to 2014, with 6,478 persons participating. Using the results of the survey, the relationship between exposure levels of heavy metals and organic chemicals and exposure factors, e.g. residential and personal lifestyle characteristics, were analyzed. Results: The exposure levels of VOCs and PAHs were significantly lower in participants living at a distance of more than 100 m from roads versus living closer to roads. Home ventilation lowered VOC and PAH exposure but did not lower chemical exposure from household products. Use of public transportation showed lower exposure to heavy metals, VOCs, and PAHs. Current smoker was significantly higher for levels of heavy metals, VOCs, and PAHs, and the exposure trend was similar for current drinkers. Physical activity was related with higher exposure to phthalates and environmental phenols. Conclusion: Our observations based on a nationally representative population for Korea show that exposure to chemicals varies by residential and personal lifestyle, and this should be considered for developing appropriate mitigation measures and policies. Given the health concerns surrounding environmental chemicals, it is necessary to develop comprehensive measures to reduce chemical exposure.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.1
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• pp.55-72
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• 1986

This study was made to determine the factors involving personal exposure levels of nitrogen dioxide for housewives living in urban area in two seasons, winter and summer. Nitrogen dioxide was measured with a small passive sampler containing triethanolamine. The samplers were set for 24 hours at three points. They were places: on the collar of the housewife to investigate the personal exposure level, near the TV in the living room (indoor level), and near the porch of their house (outdoor level). The subjects recorded the times of cooking using a gas range, using a kitchen ventilator, passive smoking, kerosene heater, total number of minutes at an open window, going out of home, etc.$\ldots. There was an apparent increase in personal exposure level in the case of the unvented heater and also an increase by cooking on a gas range. There was no marked increase in the other situations. There was an increase in the indoor level by cooking on a gas range, only in western style cooking in the winter season. Through these observations, we concluded that personal exposure level of nitrogen dioxide was strongly related to indoor nitrogen dioxide level, and factors involving indoor nitrogen dioxide level seemed different between winter and summer. The most significant difference in nitrogen dioxide level was indoor pollution in the winter and the outdoor environment in the summer. The maximum personal exposure level appeared in the western and tenement house in the winter and the traditional korean house in the summer.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.1
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• pp.10-20
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• 2022

Objectives: The aim of this study is to evaluate exposure levels of the extremely low frequency magnetic fields(ELF-MF) radiated from various electric facilities in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the exposure levels of personal and local ELF-MF for the electronic facilities installed in two LCD manufacturing companies. Samplers were installed around workers' waist during working hours to identify personal exposure levels, and direct reading equipment were located at 3 cm, 10 cm, and 30 cm away from the surface of the electronic facilities to measure local exposure levels. Average and maximum(ceiling) values were calculated for personal and local exposure levels. Results: Average and maximum of personal exposure levels for each worker were 0.56(mean) ± 0.02(SE) µT and 6.31 ± 0.75 µT, respectively. Statistical analyses of the study found that maximum of the personal exposure levels for engineers was significantly higher than that for operators since engineers spend more time near the electronic facilities for repairing. The range of maximum personal exposure levels was 0.50 ~ 43.50 µT and its highest level was equivalent to 4.35 % of ACGIH(American Conference of Governmental Industrial Hygienists) exposure limit value(1 mT). Maximum of local exposure levels was 8.18 ± 0.52 µT and the electronic facilities with higher exposure levels were roof rail and electric panel, which were not related to direct manufacturing. The range of maximum local exposure levels was 0.60 ~ 287.20 µT and its highest level was equivalent to 28.7 % of the ACGIH exposure limit value. Lastly, the local exposure levels significantly decreased as the measurement distance from the electronic facilities increased. Conclusions: Maximum of personal and local exposure levels did not exceed the exposure limit value of ACGIH. However, it is recommended to keep the workers as far as possible from the sources of ELF-MF.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.569-576
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• 2019

Objectives: The main purpose of this study was to assess firefighters' daily personal noise exposure and explore noise levels related to specific tasks and their contributions to total noise exposure using 24-hour full-shift noise exposure measurements with task-based data. Methods: Noise exposure was assessed for eight firefighters (two rescuers, two drivers, and four suppressors) using time-activity diaries. We collected a total of 24 full-shift personal noise sample sets (three samples per a firefighter). The 24-hour shift-adjusted daily personal noise exposure level (L_ep,d), eight weekly personal noise exposures (L_eq,w), and 40 task-specific L_eq values (L_{eq activity}) were calculated via the ISO/NIOSH method. Results: The firefighter noise-sample datasets showed that most firefighters are exposed to noise levels above EU recommended levels at a low-action value. The highest noise exposure was for rescuers, followed by drivers and suppressors. Noise measurements with time-at-task information revealed that 82.3% of noise exposure occurred when checking equipment and responding to fire or emergency calls. Conclusions: The results indicate that firefighters are at risk of noise-induced hearing loss. Therefore, efforts at noise-control are necessary for their protection. This task-specific noise exposure assessment also shows that protective measures should be focused on certain tasks, such as checking and testing equipment.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.2
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• pp.97-102
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• 2004

The objective of this survey is to characterize personal magnetic field exposure of the general population in Korea. Participants for the survey on magnetic field exposure were selected randomly in some occupations. Those wore the magnetic field meter for about 25∼28 hours and the measured data were stored in the meter. In this first step survey, the number of participant is 244 and for the second step, about 400 participants will be surveyed in the near future. 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. Therefore the database will be able to be established to analyze the status of personal magnetic field exposure and safety.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.20-26
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• 2001

personal nitrogen dioxide(NO$_2$) exposures for 31 professional drivers were measured using passive sampler and time activity diary in Asan and Chunan area, and were estimated using time-weighted average model. Mean concentrations of driver’s indoor and outdoor were 24.7$\pm$10.7 ppb and 23.3$\pm$8.3 ppb, respectively with indoor/outdoor of 1.1. Mean personal NO$_2$ exposure was 30.3$\pm$9.7 ppb. Personal NO$_2$ exposures were strongly correlated with indoor car NO$_2$ levels ($R^2$=0.80) rather than residential indoor NO$_2$ level ($R^2$=0.55). and outdoor NO$_2$ level ($R^2$=0.50). The driver’s NO$_2$ exposure using LP-gas with 24.4$\pm$8.0 ppb were statistically different from those using diesel with 36.3$\pm$14.1 ppb(p<0.01). The effect of driver’s smoking for personal NO$_2$ exposure was not found. It was considered that the main NO$_2$in driver is transportation. Since drivers mostly spent their times in indoor and inside car, time-weighted average model could be used to estimated personal NO$_2$ exposure using time activity diary, Though we did not measure all microenvironments, the estimated personal NO$_2$ exposures with 26.9$\pm$10.2 ppb were statistically correlated with measured personal NO $_2$ exposures30.3$\pm$9.7 ppb ($R^2$=0.89). The mean and standard deviation of personal NO$_2$ exposure using Mote-Carlo simulation were 26.6$\pm$7.2 ppb.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.967-976
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• 2003

Volatile organic compounds (VOCs) are present in essentially all natural and synthetic materials from petrol to flowers. In this study, indoor and outdoor VOCs concentrations of houses, offices and internet-cafes were measured and compared simultaneously with personal exposures of each 50 participants in Asan and Seoul, respectively. Also, factors that influence personal VOCs exposure were statistically analyzed using questionnaires in relation to house characteristics, time activities, and health effects. All VOCs concentrations were measured by OVM passive samplers (3M) and analyzed with GC/MS. Target pollutants among VOCs were Toluene, o-Xylene, m/p-Xylene, Ethylbenzene, MIBK, n-Octane, Styrene, Trichloroethylene, and 1,2-Dichlorobenzene. Indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan except Ethylbenzene. Residential indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Relationship between personal VOCs exposure, and indoor and outdoor VOCs concentrations suggested that time-activity pattern could affect the high exposure to air pollutant. Factors that influence indoor VOCs level and personal exposure with regard to house characteristics in houses were building age, inside smoking and house type. In addition insecticide and cosmetics interestingly affected the VOCs personal exposure. Higher exposure to VOCs might be caused to be exciting increase and memory reduction, considering the relationship between measured VOCs concentrations and questionnaire (p<0.05).

• Convergence Security Journal
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• v.12 no.1
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• pp.71-77
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• 2012

Along with the development of Internet services such as Social Network Service (SNS) and blog Service, the privacy is very important in these services. But personal data is not safety from exposure to internet service. If personal data is leak out, the privacy is disclosed to hacker or illegal person and the personal information can be used in a cyber crime as phishing attacks. Therefore, the model and method that protects to disclose privacy is requested in SNS and blog services. The model must evaluate degree of exposure to protect privacy and the method protects personal information from Internet services. This paper proposes a model to evaluate risk for privacy with property of personal data and exposure level of internet service such as bulletin board. Also, we show a method using degree of risk to evaluate with a proposed model at bulletin board.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.506-514
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• 2006

The objectives of this study were to evaluate personal exposure estimated using a time activity pattern and microenvironmental model. The study was carried out for 44 children attending a primary school nearby the lines (school A) and 125 children attending a school away from 154 kV power lines (school B). For children attending school A, the estimated personal level was a little weak correlated with the measured level($Pearson\;r\;=0.34{\sim}0.35$). For children attending school B, the correlation was very low ($Pearson\;r\;=\;0.09{\sim}0.16$) using the TW A Model II, otherwise, TWA Model II-I which considered the average residential MF level according to the distance from the power line and home explained $39{\sim}53%$ of the correlation in MF personal exposures. The estimated personal exposure level was very well represented by the measured exposure level using TWA Model II-2 which consisted on spot and 24 h stationary measurements at subject's home ($Pearson\;r\;=\;0.65{\sim}0.85$). In conclusion, personal magnetic field expsoure estimated using a TWA Model II-2 should be provided for a reasonable estimate of measured exposure in schoolchildren living near the power line.

• Journal of environmental and Sanitary engineering
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• v.16 no.1
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• pp.1-8
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• 2001

Since most people spend over 80% of their time indoor, indoor air quality tends to be the dominant contributor to personal exposure. In this study, indoor and outdoor $NO_2$concentrations were measured and compared with simultaneously personal exposures of 27 house-wives and female workers of kindergarten. Time activity pattern and house characteristics were used to determine the effects of these factors on personal exposure. Since house-wives student spent most their times in indoor with mean of 89.8%, their $NO_2$ exposure was associated with indoor $NO_2$ level(r= 0.92) rather than outdoor $NO_2$ level(r= 0.87). female workers were also associated with indoor $NO_2$ level(r= 0.70) though sample number were small. Using time-weighted average model, $NO_2$ exposures of house-wives were estimated by $NO_2$ measurements in indoor home and outdoor home levels. Estimated $NO_2$ personal exposures were significantly correlated with measured $NO_2$ personal exposures (r= 0.90). These results might mean that air pollutants exposure of old and feeble persons, and infants could be estimated by measuring concentrations of indoor home.