• Journal of Environmental Science International
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• v.17 no.7
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• pp.767-774
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• 2008

This study was carried out to evaluate the characteristics of atmospheric concentrations of volatile organic compounds(VOCs) and aldehydes for near a large shipyard. Most of the painting work in marine coating is performed indoor and outdoor. Most of the VOCs are emitted to the atmosphere as the paint is applied and cures. The massive scale of a ship makes it difficult to capture the emissions from outdoor painting. The VOCs are an important health and contributors to photochemical smog. The VOCs and aldehydes samples were collected using adsorbent tube and 2,4-DNPH cartridge, and were determined by an automatic thermal desorption coupled with GC/MS and HPLC-UV analysis, respectively. A total of 16 aromatic VOCs and 12 aldehydes of environmental concern were determined. At indoor coating facilities, the most abundant compound among 16 target VOCs appeared to be m,p-xylene, being followed by o-xylene. But most of the aldehydes were extremely lower concentrations. The atmospheric concentration of VOCs, m,p-xylene concentrations were the highest and the mean value were outdoor workshop 11.323 ppb, residental area 5.134 ppb, and green area 2.137 ppb, respectively. However, the most aldehydes were extremely lower concentrations such as formaldehyde, acetaldehyde and non-detection such as iso-valeraldehyde, n-valeraldehyde and o-tolualdehyde.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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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.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.19-26
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• 2006

This study was undertaken to determine the concentrations of 15 aldehydes in air samples collected from 21 households including 9 atopy patient's homes and to assess the extent of exposure and risk for an individual due to inhalation. Of all the aldehydes identified in both indoor and outdoor environment, formaldehyde and acetaldehyde were the most abundant aldehydes, which were occupied $60\%\;and\;17\%$ of total amount, respectively. The geometric mean concentration of formaldehyde and acetaldehyde in indoor air were $170.5\pm1.9\;{\mu}g/m^3\;and\;47.3\pm1.5\;{\mu}g/m^3$, respectively. There existed a strong correlation between formaldehyde, acetaldehyde and other aldehydes. And the ratio of indoor and outdoor concentrations (I/O) exceeded 1.0 for almost every measured aldehydes except m-tolualdehyde... No associations were found between the level of aldehydes and either housing characteristics or living habits in most of the samples with only a few exception. And the concentrations of all aldehydes indoor air between atopy patient's homes and control homes were not significant(p>0.05). Formaldehyde and acetaldehyde exposures and risks were estimated by using the inhalation unit risk, mean concentrations and the 95th percentiles, and which were $2.6\times10^{-3}\;and\;1.1\times10^{-4}$, respectively. The mean and the 95th percentile risk estimates were 25 times higher for formaldehyde than for acetaldehyde in homes.

• 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.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.50-51
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• 2008

• Korean Journal of Remote Sensing
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• v.36 no.6_3
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• pp.1721-1732
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• 2020

Elementary school students spend a lot of time in a school and are more exposed to indoor air pollution. Also the students are physically growing and have a relatively high respiratory rate per unit weight compared to adults, so it is known that there is a high sensitivity to indoor air pollution. Therefore, indoor air quality in a school is becoming an important factor for the student's health. In this study, a correlation analysis using levels of indoor and outdoor Particulate Matter (PM) measured from five elementary schools in Seoul was performed to evaluate the effect of outdoor PM on indoor PM. PM ratio and indoor/outdoor (I/O) ratio were also analyzed to investigate the actual condition of indoor air quality and effect of outdoor PM on indoor PM. As a result, the correlation between indoor and outdoor PM in elementary school was more significant in PM2.5 and PM1 than PM10. In the case of I/O ratio, the I/O ratio of PM10 was higher than that of 1 in four elementary schools except SD (BB:2.21, NS: 1.67, IS: 1.73, SI: 1.17). This indicates that the activity of students has a great effect on the concentration of indoor PM10.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.267-274
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• 2018

Objectives: This study examined the impact of a smoke-free policy on indoor air quality at indoor recreation facilities by assessing $PM_{2.5}$ concentrations before and after the implementation of the new policy. Methods: Using real-time monitors, $PM_{2.5}$ concentrations were measured in 50 billiard rooms and 50 golf simulator rooms in Seoul, Korea. The characteristics of the indoor recreation facilities, smoking status, and atmospheric conditions were recorded at the same time.After the enforcement of a smoke-free policy, $PM_{2.5}$ concentrations, installation of smoking room, and smoking status were examined when the facilities were revisited. Results: Almost a half of the billiard rooms and over 80% of golf simulator rooms were located underground. Seventy percent of the billiard rooms and one hundred percent of the golf simulator rooms were equipped with a local exhaust ventilation system. After the implementation of the smoke-free policy, 46% of the billiard rooms and 20% of the golf simulator rooms newly installed a smoking room. In the billiard rooms with a newly-installed smoking room, the $PM_{2.5}$ concentrations decreased from 97.9 to $45.6{\mu}g/m^3$ after the implementation of the smoke-free policy. The same change of 29.0 to $ 26.3{\mu}g/m^3$ was not statistically significant in golf simulator rooms. Indoor $PM_{2.5}$ concentrations were correlated with outdoor $PM_{2.5}$ concentrations, number of smokers, and number of people in the room. Conclusions: The smoke-free policy for indoor recreation facilities was not effective at making the indoor spaces free from second hand smoke. Although a few billiard rooms installed a smoking room, indoor $PM_{2.5}$ concentrations were still higher than those of outdoor $PM_{2.5}$ or atmospheric $PM_{2.5}$. Stricter enforcement of the smoke-free policy should be achieved to prevent secondhand smoke exposure.

• Journal of Environmental Science International
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• v.19 no.1
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• pp.1-8
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• 2010

Only limited information is available on the measured exposure levels of residents according to the construction age of apartments. As such, present study was conducted to measure and to compare the bedroom, living-room, and outdoor air levels of MTBE and benzene, toluene, ethyl benzene and m,p-xylene(BTEX) in both newer and older apartments. For both newer and older apartments, all the compounds except for MTBE showed significantly higher levels in bedrooms or living-rooms as compared to the outdoor concentrations. The ratio of bedroom or living-room median concentration to outdoor concentration was close to 1 for MTBE, whereas it was larger than 1 for other target compounds. It was also found that the bedroom and living-room appeared to have similar indoor sources and sinks for BTEX, but not for MTBE. The median concentration ratios of the newer apartments to the older apartments ranged from 1.63 to 1.81, depending upon the compounds. In contrast, the MTBE concentrations did not differ significantly between the newer and older apartments, thereby suggesting that although newer buildings could emit more VOCs, this is not applicable to all VOCs. Conclusively, the findings of present study should be considered, when designing exposure studies associated with VOC emissions in buildings and/or managing indoor air quality according to construction age of buildings.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.4
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• pp.343-360
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• 1998

In this study, comprehensive air quality monitoring was undertaken with a variety of objectives to collect data on the levels of various indoor and ambient air quality parameters in the urban areas of Seoul and Taegu. The sampling sites were comprised of six offices, six residences and six restaurants in each city. The ambient air adjacent to the indoor sites was also simultaneously sampled for the same constituents. The sampling was conducted in two phases: summer of 1994 and winter of 1994/95. A range of air quality parameters were measured simultaneously, which include RSP, CO, COB, NOB, a range of VOC, airborne microbials, temperature, and relative humidity. The indoor and ambient levels of the pollutants measured in this study varied widely between the three types of environments studied. Comparison of median values for the three groups revealed that restaurants had higher indoor levels of most pollutants than homes or offices. There was also a clear pattern of the indoor levels of target pollutants being higher than those outdoors, particularly in restaurants. Concentrations of CO and most of the VOC were found to be significantly higher in the commercial districts, indicating the influence of vehicle exhaust emissions. A very wide range of VOC levels was documented in this study. Although median indoorloutdoor ratios indicated a generally increasing level of VOC indoors when compared to those outdoors, no statistically significant differences were found between indoor and outdoor VOC levels in homes and offices, implying the importance of ambient air quality in determining the quality of indoor air for homes and offices in urban areas. In addition, there was a general pattern of increasing concentrations from summer to winter, and similarly from outdoor to indoor air for nearly all target compounds. The seasonal differences in median levels were very clearly seen for fuel combustion related pollutants such as RSP, CO and VOC, this being attributed to the effects of increased fuel consumption during the cold season and to meteorological factors.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.545-552
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• 2000

Eight aromatic hydrocarbons were quantified in a newly constructed building before occupancy during the period of November 1997 to January 1998. Air samples were collected in 6 L stainless steel canisters for 8 hours based on working hour. It was found that the measured total concentration of aromatic hydrocarbons decreases rapidly with time up to a steady-state value. However, the fractions for each aromatic hydrocarbon were greatly changed with time. The concentration ratios of indoor to outdoor for aromatic hydrocarbons are greater than 1 during early period of the measurement, and the ratios decrease with time. The concentrations of toluene, m+p-xylene, ethylbenzene, and o-xylene are much higher than those of styrene, 1, 2, 4-trimethylbenzene, and 1, 3, 5-f trimethylbenzene in indoor air. The concentration fractions of m+p-xylene, ethylbenzed, and o-xylene in indoor air are about twice as hight as those in outdoor air measured during the similar period. It was concluded that the aromatic hydrocarbons were emitted from building materials, paints, and adhesives in an-built building.