• Title/Summary/Keyword: air exposure time

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Spacio-temporal Analysis of Urban Population Exposure to Traffic-Related air Pollution (교통흐름에 기인하는 미세먼지 노출 도시인구에 대한 시.공간적 분석)

  • Lee, Keum-Sook
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.1
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    • pp.59-77
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    • 2008
  • The purpose of this study is to investigate the impact of traffic-related air pollution on the urban population in the Metropolitan Seoul area. In particular, this study analyzes urban population exposure to traffic-related particulate materials(PM). For the purpose, this study examines the relationships between traffic flows and PM concentration levels during the last fifteen years. Traffic volumes have been decreased significantly in recent year in Seoul, however, PM levels have been declined less compare to traffic volumes. It may be related with the rapid growth in the population and vehicle numbers in Gyenggi, the outskirt of Seoul, where several New Towns have been developed in the middle of 1990's. The spatial pattern of commuting has changed, and thus and travel distances and traffic volumes have increased along the main roads connecting CBDs in Seoul and New Towns consisting of large residential apartment complexes. These changes in traffic flows and travel behaviors cause increasing exposure to traffic-related air pollution for urban population over the Metropolitan Seoul area. GIS techniques are applied to analyze the spatial patterns of traffic flows, population distributions, PM distributions, and passenger flows comprehensively. This study also analyzes real time base traffic flow data and passenger flow data obtained from T-card transaction database applying data mining techniques. This study also attempts to develop a space-time model for assessing journey-time exposure to traffic related air pollutants based on travel passenger frequency distribution function. The results of this study can be used for the implications for sustainable transport systems, public health and transportation policy by reducing urban air pollution and road traffics in the Metropolitan Seoul area.

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Analysis of Cosmic Radiation Exposure for Domestic Flight Crews in Korea

  • Ahn, Hee-Bok;Hwang, Junga;Kwak, Jaeyoung;Kim, Kyuwang
    • Journal of Astronomy and Space Sciences
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    • v.39 no.2
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    • pp.51-57
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    • 2022
  • Cosmic radiation exposure of the flight crews in Korea has been managed by Radiation Safety Management around Living Life Act under Nuclear Safety and Security Commission. However, the domestic flight crews are excluded from the Act because of relatively low route dose exposure compared to that of international flight crews. But we found that the accumulated total annual dose of domestic flight crews is far from negligible because of relatively long total flight time and too many flights. In this study, to suggest the necessity of management of domestic flight crews' radiation exposure, we statistically analyzed domestic flight crew's accumulative annual dose by using cosmic radiation estimation models of the Civil Aviation Research Institute (CARI)-6M, Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS), and Korean Radiation Exposure Assessment Model (KREAM) and compared with in-situ measurements of Liulin-6K LET spectrometer. As a result, the average exposure dose of domestic flight crews was found to be 0.5-0.8 mSv. We also expect that our result might provide the basis to include the domestic flight crews as radiation workers, not just international flight attendants.

The Study on the Atmospheric Corrosion Tests of Materials in Northeast Asia (동북 아시아 지역에서의 대기중 재료부식 시험에 관한 연구)

  • 김선태;임봉빈
    • Journal of Environmental Science International
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    • v.7 no.3
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    • pp.361-368
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    • 1998
  • The structure such as building and cultural properties was composed of various materials like wood, metal and stone that have been utilized and exposed to air, wind and rain far a long time. However, because of their special characteristics as structure, collecting of samples that may involve their destruction cannot be permitted, ever for material analysis. Therefore, h order to study the Influence of atmospheric pollution on structure, atmospheric corrosion tests were achieved by making use of materials(bronze. ancient copper, copper, steel and marble) in field exposure tests. Atmospheric exposure sites are selected from places which are characterized by urban, rural, Industrial and marine enoronments In Northeast Asia. According to the results of atmospheric corrosion tests: The corrosion rates of Industrial states In china were more serious than other sampling sites. In the correlation of meteorological factors. wet hours was defiled as Intogeacted hours under that atmospheric temperature is above $0^{\circ}C$ and relative humidity in above 80% that has a great influence on corrosion tests of materials in case of a short time. The relative humidity was above about 75% that resulted in great increase of corrosion rates. In the esimation of corrosion rates between materials, corrosion rates of steel was about thirty times and decuple larger than that of other materials excluding marble in unshelterd exposure and In sheltered exposure.

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Relevance between Total Volatile Organic Compound (TVOC) Exposure Level and Environmental Diseases Within Residential Environments (주거환경 내의 Total Volatile Organic Compounds (TVOC) 노출수준과 환경성질환과의 관련성)

  • Lee, Dong-Hyun;Chung, Jin-Do
    • Journal of Environmental Health Sciences
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    • v.37 no.3
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    • pp.193-200
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    • 2011
  • Objective: The purpose of this study is to compare and analyze the level of exposure to volatile organic compounds for different kinds of households in apartments or houses and analyze the relation between atopy-related symptoms and concentration of volatile organic compounds in order to improve indoor air quality and start to build a process to prevent environmental diseases. Method: From July 2010 to November 2010, TVOC concentration levels were measured and analyzed in 402 general households and 236 weak households, totalling 638 households. Residents were asked to fill out a survey on environmental disease. All resources were analyzed using SPSS 12.0 program. Result: In comparing the differences in concentration levels of volatile organic compounds for different types of households, including existing apartments and houses, the type of housing did not affect the concentration level of volatile organic compounds, but the relevance with skin trouble, diagnosed atopy, and atopy systems all had statistical similarities. Moreover, above-limit volatile organic compounds showed statistical relevance with amount of ventilation, time of construction, skin trouble, diagnosed atopy and atopy symptoms. Conclusion: The study concludes that as the time of construction recedes further into the past and as the amount of ventilation is higher, the exposure level to volatile organic compounds was lower and the group that were suffering from atopy symptoms had higher exposure to volatile organic compounds.

Wear Comfort of Firefighters Protective Gloves in Dry and Wet Conditions at 70℃ Air Temperature with Radiant Heat (기온 70℃의 복사열 노출 환경에서 건조와 젖은 상태의 소방용 보호장갑 착용 시 쾌적성 평가)

  • Kim, Dami;Kim, Dohyung;Lee, Joo-Young
    • Journal of Korean Living Environment System
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    • v.24 no.1
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    • pp.95-106
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    • 2017
  • The purpose of this study was to evaluate comfort functions while wearing firefighters' protective gloves in dry and wet conditions at $70^{\circ}C$ air temperature with radiant heat. Four types of firefighting gloves from Korea, Germany, United States, and Japan were evaluated in both dry and wet conditions by eight male firefighters. Firefighters put their hands and forearms wearing gloves into a hands-radiant chamber that maintained at an air temperature of $70{\pm}2^{\circ}C$ ($T_a$) and globe temperature $106^{\circ}C$ ($T_g$). During the exposure, subjects followed a fixed protocol of manual movements and stopped the exposure when they felt being intolerable. Results showed that completion time was extended by 6 min on average when gloves got wet and 15 min for the Japanese gloves was extended when compared to its dry condition (p<.001); microclimate humidity on the palm at the last stage was greater for wet conditions than dry conditions in the all gloves; and skin temperatures on mid-fingertip, palm, and hand were significantly lower for wet conditions than dry conditions especially for Japanese gloves (p<.001). These results indicate that the exposure time without thermal pain to radiant heat could be extended by wetting gloves during the low radiant heat exposure.

Methodology for Quantitative Monitoring of Agricultural Worker Exposure to Pesticides (농작업자에 대한 농약 노출의 정량적 측정 방법)

  • Kim, Eun-Hye;Lee, Hye-Ri;Choi, Hoon;Moon, Joon-Kwan;Hong, Soon-Sung;Jeong, Mi-Hye;Park, Kyung-Hun;Lee, Hyo-Min;Kim, Jeong-Han
    • The Korean Journal of Pesticide Science
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    • v.15 no.4
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    • pp.507-528
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    • 2011
  • Agricultural workers who mix/loads and spray pesticide in fields expose to pesticide through dermal and inhalation routes. In such situation, exposed amount should be measured quantitatively for reasonable risk assessment. Patch, gloves, socks and mask will be good materials for monitoring for dermal exposure while personal air monitor equipped with solid adsorbent and air pump will be a tool for inhalation exposure. For extrapolation of absorbed amount in dermal exposure matrices and of trapped amount in solid sorbent to total deraml or inhalation exposure, Korean standard body surface area and respiration rate were proposed in substitution of EPA data. Important exposure factors such as clothing and skin penetration ratio of dermal and inhalation exposure were suggested based on Spraying time for exposure monitoring must be long enough that the amount of pesticide to get absorbed/trapped in exposure matrices results in reasonable analytical value. In domestic case for the both of speed sprayer and power spray machine, spraying time of 20~40 minutes (0.1~0.2 ha) will be reasonable per single replicate before extrapolating to 4 hours a day with triplicates experiment.

Hazardous Organic Compounds Concentration of Newly Built School Classroom and Neurobehavioral Performance of Elementary School Children (신축학교 교실 실내공기 중 유해유기물질 농도와 초등학생의 신경행동기능에 관한 연구)

  • Kwaak, Hong-Taak;SaKong, Joon
    • Hwankyungkyoyuk
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    • v.24 no.3
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    • pp.18-25
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    • 2011
  • This study was conducted to evaluate the effects of volatile organic compounds and formaldehyde of newly-built school classroom indoor air on the neurobehavioral functions of students. The elementary schools that were opened in September 2008(as of September 2008) was selected for newly-built school and the elementary school that were opened in March 2006 was selected for control group schools. The concentration of formaldehyde(HCHO), a hazardous organic compound that exists in the air of classrooms, exceeded the standard value of $108.2{\mu}g/m^3$ in newly-built schools while it was $60.8{\mu}g/m^3$ in control group schools, which is around 60% of the standard concentration. However, the concentration of the total volatile organic compounds(TVOCs) was $788.9{\mu}g/m^3$ and $756.1{\mu}g/m^3$ in newly-built schools and control group schools respectively, which are approximately two times higher than the standard concentration. In newly-built schools, the mean reaction time of additions and symbol digit, respectively 3,020ms and 2,398ms in pre-exposure were increased to 3,167ms and 2,514ms respectively in post-exposure. The difference of mean reaction time between pre and post exposure was 146.8 ms, or 4.6%, and 116.7ms, or 4.8%, respectively, showing statistically-significant increase of reaction time(p<0.05). On the contrary, the difference of reaction time of both tests were not statistically significant in the control group schools. These results showed that the neurobehavioral performance of newly-built schools students were affected by volatile organic compounds and formaldehyde of classroom indoor air.

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Assessment of Exposure to and Risk of Formaldehyde and Particulate Matter (PM10 and PM2.5) by Time Activity Applying Real-Time Indoor and Outdoor Monitoring (실내·외 실시간 모니터링을 활용한 폼알데하이드 및 미세먼지(PM10, PM2.5)의 거주시간별 노출 및 위해도 평가)

  • Yoon, Danki;Namgoung, Sunju;Kong, Hyekwan;Hong, Hyungjin;Lim, Huibeen;Park, Sihyun;Lee, Hyewon;Lee, Jungsub;Lee, Cheolmin
    • Journal of Environmental Health Sciences
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    • v.45 no.6
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    • pp.646-657
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    • 2019
  • Objectives: The purpose of this study was to suggest methods to investigate continuous monitoring of concentration levels and assess the exposure of individuals considering the actual time activity of residents for formaldehyde and particulate matter (PM10, PM2.5) in the indoor and outdoor air of a house, assess the health risks of children and adults based on the results of the exposure assessment, and provide basic data on studies for assessing exposure and health risks in Korea in the future. Methods: The concentration levels of formaldehyde and particulate matter were measured in a family home in Gyeonggi-do Province from April 25 to July 31, 2019, using electrochemical sensors (formaldehyde) and light scattering sensors (PM10, PM2.5). Risk assessment by the duration of exposure by time activity was performed by dividing between weekdays and weekends, and indoors and outdoors. Results: The greatest level of carcinogenic risk from inhaling formaldehyde was indoors during the weekdays for both children and adults. For children, the risk was at 7.5 per approximately 10,000 people, and for adults, the risk was at 4.1 per approximately 10,000 people. PM10 and PM2.5 also showed the greatest values indoors during the weekdays, with children at 1.7 people and 1.4 per approximately 100 people, respectively, and adults at 8.2 per approximately 1,000 and 1.8 per approximately 100 people, respectively. Conclusions: The risks of formaldehyde, PM10 and PM2.5 were shown to be high indoors. Therefore, consideration of exposure assesment for each indoor pollutant and management of indoor air quality is necessary.

Exposure Assessments for Children in Homes and in Daycare Centers to NO2, PMs and Black Carbon

  • Lee, Jae Young;Kim, Changhyeok;Kim, Jongbum;Ryu, Sung Hee;Bae, Gwi-Nam
    • Asian Journal of Atmospheric Environment
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    • v.12 no.3
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    • pp.204-214
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    • 2018
  • Indoor air quality was investigated in homes and daycares located in areas with heavy traffic in Seoul, South Korea from November 2013 to January 2014. Indoor and outdoor air quality measurements were collected for 48 hours in four children's homes and daycare centers. The I/O ratio (Indoor to outdoor ratio) for each major air pollutant ($NO_2$, black carbon, $PM_{10}$, and $PM_{2.5}$) was calculated, and $NO_2$ and $PM_{10}$ concentration profiles were analyzed based on indoor activity diaries recorded during the 48 hours. Most I/O ratios for $NO_2$, black carbon, $PM_{10}$, and $PM_{2.5}$ at daycare centers were less than one. At homes, I/O ratios for black carbon, $PM_{10}$, and $PM_{2.5}$ were less than one; however, most I/O ratios for $NO_2$ were greater than one due to the usage of gas stoves. The children's exposure to indoor air pollutants was calculated using a time-weighted average exposure method, and the daily intake level for each pollutant was determined.

Childrens' Health Risk Assessment on Indoor Hazardous Air Pollutants of Preschool Facility (유아교육시설 내 실내공기유해오염물질에 대한 어린이 건강위해성평가)

  • Koh, Yeon-Jung;Kim, Shin-Do;Park, Suk-Young;Jang, Seong-Ki
    • Journal of Environmental Health Sciences
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    • v.35 no.2
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    • pp.78-85
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    • 2009
  • In this study, the hazard rate of the indoor environment of Children's Educational Facilities in Seoul was conducted, in order to determine how the indoor environments of these facilities, where infants and children spend the most time of their away from home day, can effect their health. The way of measurement and analysis were done according to the Indoor Air Quality Standard Method, and the Risk Assessment was accomplished with several significant ways - Hazard Identification, Exposure Assessment, Dose-response Assessment, Risk Characterization, which are deighed by National Research Council (NRC). On each exposure factors, documentary and questionary research such as Epidemiological study and Toxicological study were conducted. The result of the CTE (Central tendency exposure) of Formaldehyde and Benzene by Monte-Carlo simulation was $6.79{\times}10^{-6}$, $2.50{\times}10^{-7}$ which in the case of Formaldehyde exceeded the permitted standard ($10^{-6}$) of the US EPA. The RME(Reasonable maximum exposure) was $7.31{\times}10^{-5}$, $2.65{\times}10^{-6}$ which did not exceed $10^{-4}$, the maximum permitted standards in the US EPA.