• Title, Summary, Keyword: personal exposure

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Estimation of Total Exposure to Benzene, Toluene and Xylene by Microenvironmental Measurements for Iron Mill Workers (제철소 근로자의 벤젠/톨루엔/크실렌 국소환경 측정을 이용한 총 노출 예측)

  • Kim, Young-Hee;Yang, Won-Ho;Son, Bu-Soon
    • Journal of Environmental Health Sciences
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    • v.33 no.5
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    • pp.359-364
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    • 2007
  • The aim of this study were to assess the personal exposure to volatile organic compounds (VOCs) and to estimate the personal exposure using time-weighted average model. Three target VOCs (benzene, toluene, xylene) were analyzed in personal exposure samples and residential indoor, residential outdoor and workplace indoor microenvironments samples in the iron mill 30 workers during working 5 days. Personal exposure to VOCs significantly correlated with workplace concentration p<0.05), suggesting workplace had strong source and major contribution to personal exposure. Personal exposure could be estimated with time activity pattern and time weighted average (TWA) model of residential indoor and workplace concentrations measured. Time weighted mean microenvironments concentrations were close approximately of personal exposure concentrations. Total exposure for participants can be estimated by TWA with microenvironments measurements and time activity pattern.

Scenario Analysis of Personal Nitrogen Dioxide Exposure with Monte Carlo Simulation on Subway Station Workers in Seoul (확률론적 모의실험 기법을 이용한 일부 지하철 근무자들의 이산화질소 개인노출 시나리오 분석)

  • 손부순;장봉기;양원호
    • Journal of Environmental Science International
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    • v.10 no.3
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    • pp.195-200
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    • 2001
  • The personal exposures of nitrogen dioxide(NO$_2$), microenvironmental levels and daily time activity patterns on Seoul subway station workers were measured from February 10 to March 12, 1999. Personal NO$_2$exposure for 24 hours were 29.40$\pm$9.75 ppb. NO$_2$level of occupational environment were 27.87$\pm$7.15 ppb in office, 33.60$\pm$8.64 ppb in platform and 50.13$\pm$13.04 ppb in outdoor. Personal exposure time of subway station workers was constituted as survey results with $7.94\pm$3.00 hours in office, $2.82\pm$1.63 hours in platform and 1 hours in outdoor. With above results, personal $NO_2$exposure distributions on subway station workers in Seoul were estimated with Monte Carlo simulation which uses statistical probabilistic theory on various exposure scenario testing. Some of distributions which did not have any formal patterns were assumed as custom distribution type. Estimated personal occupational $NO_2$exposure using time weighted average (TWA) model was 31.$29\pm$5.57 ppb, which were under Annual Ambient Standard (50ppb) of Korea. Though arithmetic means of measured personal $NO_2$exposure was lower than that of occupational $NO_2$exposure estimated by TWA model, considering probability distribution type simulated, probability distribution of measured personal $NO_2$exposures for 24 hours was over ambient standard with 3.23%, which was higher than those of occupational exposure(0.02%). Further research is needed for reducing these 24 hour $NO_2$personal excess exposures besides occupational exposure on subway station workers in Seoul.

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Determination of Nitrogen Dioxide Exposure for University Students by Activity Pattern of Weekday and Weekend (평일과 주말의 활동변화에 따른 대학생들의 이산화질소 노출)

  • 양원호;손부순;박종안;정문호
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.58-64
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    • 2000
  • Indoor air quality tends to be the dominant contributor to personal exposure, because most people spend over 80% of their time indoors. In this study, indoor and outdoor NO$_2$ concentrations were measured and compared with simultaneously personal exposures of 21 university students in weekday and weekend. House characteristics and activity pattern were used to determine the impacts of these factors on personal exposure. Since university students spent most of their times in indoor, their NO$_2$ exposure was associated with indoor NO$_2$ level rather than outdoor NO$_2$ level both weekday and weekend in spite of different time activity. Using time-weighted average model, NO$_2$ exposures of university students were estimated by NO$_2$ measurements in indoor home, indoor school, and outdoor home levels. Estimated NO$_2$ personal exposures were significantly correlated with measured NO$_2$ personal exposures($r^2$=0.87). However, estimated personal NO$_2$ exposures by time-weighted average model were underestimated, comparing with the measured personal NO$_2$ exposure. Using multiple regression analysis, effect of personal NO$_2$ exposure for transportation was confirmed.

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Estimation of ELF-MF Exposure Levels in the Korean Population through 24-Hour Personal Exposure (개인 노출량 조사를 통한 한국인의 극저주파 자기장 노출 수준)

  • Jung, Joon-Sig;Kim, Keun-Young;Hong, Seung-Cheol;Cho, Yong-Sung;Kim, Yoon-Shin
    • Journal of Environmental Health Sciences
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    • v.38 no.1
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    • pp.18-30
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    • 2012
  • Objectives: The purpose of this study was to estimate the exposure level to extremely low frequency-magnetic fields (ELF-MF) among a selected Korean population using 24-hour personal exposure measurement. Methods: Participants were randomly selected for the measurement of MF exposure under the assumption that the subjects are representative of the overall Korean population. Levels of personal exposure to MF were measured according to the subject's daily activities. Results: The 24-hour time-weighted average (TWA) of 250 participants was $1.56{\pm}4.56$ mG (GM, GSD: 0.79, 2.46 mG). Personal exposure levels for females were higher than for males. The highest personal exposure level was shown in the age group between 20-60 years old. Personal exposure levels according to job category were higher for the non-occupational group than for the occupational group. Conclusions: Our results showed MF exposure exceeding 2 mG per day among 11.3% of the Korean population, indicating a somewhat higher percentage compared to the EMF RAPID Program's results for the U.S population.

Affecting Factors of Personal Exposure to Toluene according to Sociodemographic Characterization and Time-activity Pattern (사회·인구학적 요인과 시간활동양상에 따른 톨루엔 개인노출의 영향요인 분석)

  • Jung, Soon-Won;Lee, Seok-Yong;Kim, Hyun jeong;Choi, Wookhee;Kim, Suejin;Yu, Seungdo;Yang, Wonho
    • Journal of Environmental Health Sciences
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    • v.43 no.2
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    • pp.157-166
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    • 2017
  • Objectives: Exposure to hazardous air pollutants could be affected by sociodemographic factors such as age, gender and more. Information on time spent in microenvironments has a critical role in exposure assessment. The purpose of this study was to analyze the exposure pathways which influence personal exposure through time-activity patterns and sociodemographic factors. Methods: A total of 379 subjects were collected from the second term of the Korean National Environmental Health Survey. A questionnaire survey in relation to sociodemographic factors and a time-activity diary were carried out for personal exposure to toluene. Focusing on personal exposure to toluene, factors affecting personal exposure were analyzed using multiple regression analysis. Results: Participants spent their time in an indoor house for $16.8{\pm}4.0hr$, workplace or school $2.3{\pm}3.5hr$, and other indoor $2.1{\pm}2.2hr$. Sociodemographic factors were significantly different among each personal exposure and microenvironment. Time of staying at an office turned out to be a main factor from point of exposure in exposure pathway using multiple regression analysis. As a result, this means that exposure may be different according to the time of staying in each microenvironment. Conclusions: Personal exposure to air pollutants might be decided by time-activity pattern indicating when, where, and which activities people pursue, as well as individual sociodemographic factors.

Exposure Assessment and Estimation of Personal Exposure for Nitrogen Dioxide Using Time Weighted Average Model (시간가충치 평균모델을 이용한 이산화질소의 노출평가 및 예측)

  • 양원호;이선화;백도명
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.3
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    • pp.251-258
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    • 2001
  • Indoor and outdoor nitrogen dioxide(NO$_2$) concentrations of 122 houses were measured and compared with measurements of personal NO$_2$ exposure simultaneously . Time activity patterns were used to determine the impacts on NO$_2$ exposure assessment and time weighed average model to estimate the personal NO$_2$ exposure. Most people spent their times more than 80% of indoor and more than 50% in home, respectively. Personal NO$_2$ esposure was found to be significantly associated with both indoor NO$_2$ concentration(r=0.70) and outdoor NO$_2$ concentration (r=0.68). Using time weighted average model, personal NO$_2$ exposure was estimated with NO$_2$ measurements in indoor home, indoor workplace and outdoor home. The estimated NO$_2$ measurements were significantly correlated with measured personal exposures(r=0.69, N=122). For the difference between measured and estimated NO$_2$ exposures by multiple regression analysis showed that NO$_2$ concentrations in near workplace and other outdoors of no NO$_2$ measurements affected the personal NO$_2$ exposures(p=0.023).

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Time-activity Patterns and PM2.5 Exposure of the Elderly in Urban and Rural Areas (도시와 농촌 거주 노령인구의 시간활동양상 차이와 초미세먼지 (PM2.5) 노출)

  • Lim, Chaeyun;Guak, Sooyoung;Lee, Kiyoung;Hong, Yun-Chul
    • Journal of Environmental Health Sciences
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    • v.42 no.1
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    • pp.1-9
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    • 2016
  • Objectives: Personal exposure to air pollution is affected by contact over time and by location. The purpose of this study was to determine the relationship between personal exposure to $PM_{2.5}$ and the time-activity patterns of the elderly in urban and rural areas. Methods: A total of 44 elderly participants were recruited for a 24-hour $PM_{2.5}$ personal exposure measurement. Twenty-four were from Seoul (urban area) and 20 were from Asan (rural area). Energy expenditure and spatiotemporal positioning were monitored through $PM_{2.5}$ measurement. Spearman correlation analysis was conducted to determine the relationship between $PM_{2.5}$ and time-activity pattern. Results: Daily average $PM_{2.5}$ personal exposures were $19.1{\pm}9.7{\mu}g/m^3$ in Seoul and $29.1{\pm}16.9{\mu}g/m^3$ in Asan. Although outdoor exposure was higher in Seoul than in Asan, residential indoor exposure was higher in Asan than in Seoul. Higher $PM_{2.5}$ personal exposure in Asan could be explained by longer time in residential indoor environments and higher indoor $PM_{2.5}$ concentrations. Seoul elderly had higher energy expenditure, which may be due to the use of mass transportation. Conclusion: Personal exposure to $PM_{2.5}$ was higher among Asan elderly than Seoul elderly because of high residential indoor concentrations and longer residential time. Lack of energy spent and higher personal exposure to $PM_{2.5}$ might have led to higher risk among the Asan elderly.

Effects of Human Activity Patterns on Personal Exposure Levels of Nitrogen Dioxide in A-San Area (아산지역에 있어서의 $NO_{2}$ 개인 피폭량에 미치는 각종 생활행동 패턴의 영향)

  • 손부순;김대선;정문식
    • Journal of environmental and Sanitary engineering
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    • v.11 no.3
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    • pp.47-52
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    • 1996
  • Personal exposure levels of $NO_{2}$ for office workers and housewives Living in A-San and neighboring prefectures were measured in two seasons with $NO_{2}$ filter badge. $NO_{2}$ concentrations in indoor and outdoor air in their offices and houses were also measured in the same periods. Personal exposure levels in winter ranged from 13 to 132 ppb and its distribution pattern was remarkably different from the other seasons (15.2-17.9 ppb). This fact suggests that use of heating apparatus affects largely $NO_{2}$ indoor air pollution in winter seasons. Actually, $NO_{2}$ exposure levels of subjects used Kerosene heater (43.6ppb) and gas heater (33.4ppb) were higher than those of subjects unused heating apparatus (18.0ppb). Personal exposure levels of $NO_{2}$ for man and woman Living in the same houses were correlated well each other. The time spent indoors for office workers and housewives were both longer than 22 hour a day. Home staying time was about 60% of total indoor staying time for office workers and 90% or more for housewives. Personal exposure levels were significantly related to indoor exposure levels at home all seasons. Furthermore, personal exposure levels could be estimated from $NO_{2}$ concentrations and staying times in various Living environment.

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Evaluation of Passive Monitor for the Measuring of Personal Exposure to Nitrogen Dioxide in Indoor and Outdoor Air (실내 및 실외 공기중 이산화질소의 개인 노출량 측정을 위한 수동식 시료채취기의 성능평가)

  • 양원호;이기영;백도명
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.625-631
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    • 2000
  • Practical devices for measuring personal exposure to nitrogen dioxide(NO$_2$) have been made for epidemiological studies of the health effects of air pollution Standard methods for NO$_2$ measurement such as the chemiluminescent method and Saltzman method are not suitable for personal exposure because they are heavy, large and complicated to operate. In this study, a passive monitor was tested for the measurements of indoor and outdoor NO$_2$ level. Through a comparative analysis of data sets obtained by on-site chemiluminescence system, we assessed the accuracy and precision of NO$_2$ passive monitors. We also examined the possibility of passive monitor in the study of indoor, outdoor and personal NO$_2$ exposure. The accuracy and precision of NO$_2$ passive monitor were analyzed assuming measurements of on-site chemiluminescence system is reference value and using duplicated measure- ments, respectively. From these analysis the NO$_2$ passive monitor was useful for measuring indoor, outdoor and personal exposure. And NO$_2$ level from on-site chemiluminescence systems could not properly represent the personal NO$_2$ exposure as well as indoor and outdoor level of ones house. Personal exposures were correlated more strongly with indoor NO$_2$ concentrations than with outdoor NO$_2$ concentrations. Since activity pattern of each person is different, it was considered that personal daily behavior and life-style might prevent the air pollutant exposure.

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Differences of Chemical Exposure Levels according to Residential and Personal Life-style Characteristics of Korean adult population - from Korean National Environmental Health Survey (주거환경 및 개인 생활습관에 따른 화학물질 노출수준 차이 - 국민환경보건기초조사)

  • Hwang, Moon-Young;Hong, Soo-Yoen;Kwon, Young-Min;Jo, Hye-Jung;Park, Choong-Hee
    • 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.