• Journal of Environmental Science International
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• v.19 no.6
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• pp.671-680
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• 2010

The present study evaluated residential exposure to atmospheric formaldehyde and acetaldehyde according to distance from the a dyeing industry complex (DIC). This purpose was achieved by measuring concurrently the outdoor air concentrations in residences near the DIC and a certain distance away, plus the outdoor air concentrations at two industrial areas within the DIC boundary. Formaldehyde concentrations (median values of 24.3 and $22.5{mu}g/m^3$ in IS1 and IS2, respectively) were higher than acetaldehyde concentrations (median values of 7.4 and $7.3{mu}g/m^3$ in IS1 and IS2, respectively) at both sites. However, there was no significant difference in the industrial outdoor air concentrations of both formaldehyde and acetaldehyde between the two sites. In addition, the median formaldehyde concentration from the residential site near the DIC (RS1) was about 1.5 times higher than that from the residential site far away from the DIC(RS2), and the median acetaldehyde concentration from RS1 was about 1.3 times higher than that from RS2. It is noteworthy that the mean or median risk as well as these maximum risks are well above the USEPA's permissible risk level of $10^{-6}$ from environmental exposure. This suggests that appropriate management for formaldehyde and acetaldehyde is necessary in order to decrease risk of the residents of study areas, regardless of the distance from the DIC.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.247-255
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• 2002

Indoor and outdoor nitrogen dioxide (NO$_2$) concentrations were measured and compared with measurements of personal exposures of 95 persons in Seoul, Korea and 57 persons in Brisbane, Australia, respectively. Time activity diary was used to determine the impact on NO$_2$ exposure assessment and microenvironmental model to estimate the personal NO$_2$ exposure. Most people both Seoul and Brisbane spent their times more than 90% of indoor and more than 50% in home, respectively. Personal NO$_2$ exposures were significantly associated with indoor NO$_2$ levels with Pearson coefficient of 0.70 (p＜0.01) and outdoor NO$_2$ levels with Pearson coefficient of 0.66 (p＜0.01) in Seoul and of 0.51 (p＜0.01) and of 0.33 (p＜0.05) in Brisbane, respectively. Using microenvironmental model by time weighted average model, personal NO$_2$ exposures were estimated with NO$_2$ measurements in indoor home, indoor office and outdoor home. Estimated NO$_2$ measurements were significantly correlated with measured personal exposures (r = 0.69, p＜0.001) in Seoul and in Brisbane (r = 0.66, p＜0.001), respectively. Difference between measured and estimated NO$_2$ exposures by multiple regression analysis was explained that NO$_2$ levels in near workplace and other outdoors in Seoul (p = 0.023), and in transportation in Brisbane (p = 0.019) affected the personal NO$_2$ exposures.

• Journal of Environmental Science International
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• v.15 no.2
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• pp.101-106
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• 2006

The work of hairdressers includes washing, coloring, bleaching, permanent waving, conditioning, and cutting hair. Hairdressers are subjected to a number of physical and toxicological hazards. The toxicological hazards are those resulting from exposure to a wide range of chemicals that are usually classified active processes. In this study, twenty beauty shops were selected to assess the exposure to indoor air pollutants such as VOCs and particulate matter $(PM_{10})$ during one month from September 1 to September 30, 2003. Indoor air quality of beauty shops might be worse by vehicle emissions because the beauty shops were generally located near roadways. Personal exposures to VOCs and $PM_{10}$ were related to indoor concentrations of beauty shops. According to the questionnaire, hairdressers complained of sore throat, eye irritation, and nervousness as physical symptoms. The measured mean concentrations of respiratory particulates were $30.5ng/m^3$ in indoor, $30.5ng/m^3$ in outdoor and $44.0ng/m^3$ on personal levels. The personal concentration was found higher than indoor and outdoor concentrations. The heavy metals mean concentrations were shown as indoor (Na>Zn>Cr), outdoor (Cr>Zn>Pb), and personal (Na>Cr>Zn) levels. Conclusively, customers as well as workers in the beauty shops might be highly exposed to air pollutants from indoor and outdoor sources. Therefore, proper management should be taken to improve the indoor air quality in beauty shops.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.134-141
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• 2000

The person' spending time in underground s[aces within indoor environment show a tendency to increase every year, but in Korea, levels and sources of pollutant in underground spaces have not been well-characterized. Therefore, as part or a larger indoor environmental study, conducted at subway station in Seoul, nitrogen dioxide was measured using passive samplers in 16 subway stations, 2 tunnels and 70 workers of subway station. The mean concentrations of nitrogen dioxide in subway stations were $27.87{\pm}7.15$ ppb at station office, $35.76{\pm}8.35$ ppb at platform, $52.60{\pm}13.04$ ppb at outdoor, respectively, and the Indoor/Outdoor ratio were 0.49~0.93. The mean concentrations of nitrogen dioxide in tunnels were $44.91{\pm}4.67$ ppb in Chunggye-Nowon tunnel with a single track, $42.55{\pm}3.33$ ppb in Mokkol-Taenung tunnel with double track, respectively, and as a result of t-test, a single track levels were higher than double track levels(p<0.05). The mean personal exposure of the subject of station workers was $29.40{\pm}9.75$ ppb.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.2
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• pp.33-38
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• 1987

A pilot study on indoor air concentrations of nitrogen dioxide $(NO_2)$ was undertaken in the Seoul area, Korea dudring February-April 1986. Indoor and outdoor data on nitrogen dioxide concentrations were obtained for 48 private residences. Personal exposure to $NO_2$ was also investigated. Indoor outdoor ratio of $NO_2$ concentrations was 0.87, while the correlations between the indoor and outdoor levels were less than 0.50 for $NO_2$. Homes with an unvented space heater had average living room $NO_2$ concentrations approximately double those with a vented space heater. Residences with smokers have significantly higher living room $NO_2$ levels than those without smokers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.279-287
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• 2018

Sealants are an important element of modern architecture and serve as a building protection against weathering by providing barriers against ingress of moisture, air, and other materials. Exposure to a variety of environments often reduces lifespan due to changes in physical, chemical and mechanical characteristics, and UV, humidity, and temperature expansion are important issues that are directly related to durability. In this study, a combined deterioration test chamber was developed to simulate the environment of the open air as an instrument for verifying the durability of structural sealing materials indoors. In order to replicate special weather conditions, such as yellow dust, acid rain, and contamination by microorganisms, it was deemed impossible to replicate the outdoor environment by 100 %, and the results of the results of the results of the external exposure test of the structural sealant and the combined deterioration testing device. As a result of the displacement test of the outdoor exposure test, it was determined that the sealant was breaking apart and that it would be smooth, and the displacement would be up to three times greater than the initial material value of 1 year. The displacement test results of the combined deterioration test device show the tendency to deteriorate, decreasing the elasticity and tensile characteristics. In the case of denatured silicon, the current 400 cycles have been completed to confirm 12 months of degradation of the external exposure. The deformation of the test specimen cannot be verified with the naked eye, so it is considered that the conditions of the specimen are more stable than the silicon sealant. As a result of the outdoor exposure test, if the combined deterioration test device is structured and proposed in the relevant guidance or specification, the anticipated lifespan of 12 months in the actual use environment can be verified indoors and below 3 months later, economically.

• Journal of Environmental Science International
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• v.8 no.3
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• pp.319-323
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• 1999

This study was designed to evaluate the exposure to benzene by residents in neighborhoods near a major roadways, by persons waiting buses, and by drivers and service station attendants while refueling. It was confirmed that the outdoor air benzene concentrations near the major roadways were higher than those further away from the sources. However, neither the indoor air nor breath concentrations were different for two specified residential areas. Smoking was confirmed as an important factor for the indoor air benzene levels. Persons waiting buses, drivers and service station attendants were exposed to elevated benzene levels compared to even the residents in neighborhoods near a major roadways. The mean benzene concentration at bus stop was 2.7 to 6.9 times higher than the mean ambient air concentration. The mean benzene concentrations in the breathing zone of drivers and service station attendants were 95 to 160 and 120 to 202 times higher than the mean ambient air concentrations, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1191-1196
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• 2007

This research presents a laboratory study about an annoyance of impulsive sound caused by construction site(breaker and blasting). The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of jury test adopted a Semantic Difference Method (SDM). In the result of the Jury test for impulsive noise, the annoyance response of blasting noise was higher than that of breaker noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.714-720
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• 2008

This research presents a laboratory study about an subjective response of impulsive sound caused by leisure shooting. The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of the jury test adopted a Semantic Difference(SD) Method. In the result of the jury test for impulsive noise, the mean response rating expressed a linear relation and %HA(percent highly annoyed) displayed a exponential growth relation.

• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.255-269
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• 2003

The objective of this study was to estimate human exposure to benzo (a)pyrene through multimedia/multi-pathway exposure scenario. The human exposure scenario for benzo(a)pyrene was consisted of 12 multiple exposure pathways, and the multipathway human exposure model based on this scenario constituted. In this study, the multipathway human exposure model was used to estimate the concentrations in the exposure contact media, human intake factors and lifetime average daily dose (LAD $D_{model}$) of benzo(a)pyrene in the environment. Sensitivity analysis was performed to identify the important parameters and Monte-Carlo simulation was undertaken to examine the uncertainty of the model. The total LAD $D_{model}$ was estimated to be 5.52${\times}$10$^{-7}$ mg/kg-day (2.06${\times}$10$^{-7}$ -8.65${\times}$10$^{-7}$ mg/kg-day) using the multipathway human exposure model. The inhalation dose accounted for 78% of the total LADD, whereas ingestion and dermal contact intake accounted for 20.2% and 1.8% of the total exposure, respectively. Based on the sensitivity analysis, the most significant contributing input parameter was benzo (a)pyrene concentration of ambient air. Consequently, exposure via inhalation in outdoor/indoor air was the highest compared with the exposure via other medium/pathways.