• 한국환경보건학회지
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• 제42권1호
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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.

• 한국환경과학회지
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• 제6권6호
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• pp.659-670
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• 1997

차량 내부의 높은 휘발성 유기물질 농도와 이들 휘발성 유기물질의 독성 때문에 휘발성 유기물 질에 대한 차량 내부에서의 노출이 주요한 관심을 받고 있다. 본 연구에서는 115회의 도시 지역 (대구 광역시) 출퇴근과 9회의 정차 실험을 통해 상업용 공기정화기의 6 종류 휘발성 유기물질에 대한 제거 효율이 평가되었다. 네 종류의 운전 조건에서 수행된 정차 및 출퇴근 연구 결과, 본 연구에서 이용된 두 개의 시중 시판 차량용 공기정화기는 휘발성 유기물질에 대해 제거 효율이 없는 것으로 나타났다. 벤젠을 제외한 다섯 종류의 휘발성 유기물질의 농도는 최근 차량보다 오래된 차량 내부에서 높게 나타났다 (p<0.05). 본 연구에서 측정된 벤젠과 톨루엔의 평균 농도는 로스앤젤레스에서 측정된 값과 유사하게 나타났고, 그 이외의 미국내 비교지역의 측정 값보다는 높게 나타났다. 휘발성 유기물질에 대한 노출 및 해당 발암 위해성은 차량 내부에서 실외 공기의 약 8배 정도 높게, 그리고 실내 공기의 약 절반 정도로 산정 되었다.

• 한국환경과학회지
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• 제15권8호
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• pp.719-725
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• 2006

Since low-floor apartments ate vertically closer to patting lots and roadways, it is hypothesized that residents in low-floor apartments may be exposed to elevated ambient levels of motet vehicle emissions compared to residents in high-floor apartments. The present study examined this hypothesis by measuring two motor vehicle source-related pollutants(CO and PM10) in ambient air of high-rise apartment buildings within the boundary of industrial complexes according to atmospheric stability The ambient air concentrations of CO and PM10 were higher for low-floor apartments than for high-floor apartments, regardless of atmospheric stability, The median concentration ratio of the low-floor air to high-floor alt ranged from 1.3 to 2.0, depending upon atmospheric stabilities, seasons and compounds. Moreover, the CO and PM10 concentrations were significantly higher in the winter and in the summer, regardless of the Hoot height. Atmospheric stability also was suggested to be important for the residents' exposure of high-rise apartment buildings to both CO and PM10. The median ratios of surface inversion air to non-surface inversion air ranged from 1.2 to 1.7 and from 1.0 to 1.6 lot PM10 and CO, respectively, depending upon seasons. Conclusively, these parameters(apartment floor height, season, and atmospheric stability) should be considered when evaluating the exposure of residents, living in high-rise apartment buildings, to CO and PM10. Meanwhile, the median PMl0 outdoor concentrations were close to or higher than the Korean annual standards for PM10, and the maximum PM10 concentrations substantially exceeded the Korean PM10 standard, thus suggesting the need for a management strategy for ambient PM 10. Neither the median nor the maximum outdoor CO concentrations, however, were higher than the Korean CO standard.

• 한국안전학회지
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• 제38권3호
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• pp.10-19
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• 2023

Fall accidents account for the highest accident fatality rate in the construction industry. In addition, wearing and using a safety belt is the most realistic and important preventive measure to reduce fall accidents. Safety belts are protective devices worn by individual workers; they prevent workers from falling and allow for time to rescue the workers. However, the legal standards for safety belts only stipulate the materials, specifications, and strength of parts; there is no provision for an auxiliary rope fixing method to fix the safety belts safely. Due to this reason, workers in industrial sites arbitrarily fix and use the auxiliary rope. Currently, the most used method to fix the auxiliary rope is to tie a knot, which significantly lowers the strength of the material compared to the standard strength. Moreover, many construction sites are located outdoors, so the strength of the materials used in the auxiliary rope is inevitably reduced due to various external environmental conditions. Therefore, to solve this problem, this study was conducted to evaluate the strength of the material of the auxiliary rope for fixing the safety belt and the knot-tying method for the auxiliary rope. In this study, the exposure conditions for the effects of temperature and moisture were set to reflect the characteristics of the construction industry. The results of this study are expected to be used for standards establishment and the safe use of the auxiliary rope for safety belts in actual field applications.

• 한국콘텐츠학회논문지
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• 제15권10호
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• pp.547-560
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• 2015

최근 국내에서 크게 증가하고 있는 아웃도어레크리에이션 열풍은 여가시간과 가처분소득의 증가뿐만 아니라 대중매체와 대중문화의 상호작용의 효과로 볼 수 있다. 국내에서 대중매체를 통해서 노출되는 아웃도어레크리에이션은 실질적으로 크게 증가하고 있고, 관련 산업분야도 급속도록 성장하는 것으로 나타났다. 리얼리티 프로그램 '아빠! 어디가?'의 경우에는 여러 아웃도어레크리에이션을 통해 놀이, 재미, 경쟁, 그리고 일탈적인 특성 등을 사실적으로 노출하고 있기 때문에 관광객의 내재적 특성인 놀이성 측면이 더욱 부각이 된다. 이에 본 연구에서는 대중매체를 통한 아웃도어레크리에이션의 노출이 잠재 아웃도어 레크리니셔트에게 어떠한 영향을 미치는지를 규명하고자한다. 이러한 의사결정과정을 규명하기 위하여 인간의 행동에 대한 설명력이 높은 계획된 행동이론에 성인의 재미와 놀이의 내재적 특성인 놀이성을 추가하였다. 연구결과, 놀이성은 태도, 주관적 규범, 지각된 행동통제에 크게 유의한 영향을 미치는 것으로 나타났고, 태도, 주관적 규범, 지각된 행동통제 또한 행동의도에 유의한 영향을 미치는 것으로 나타났다. 이는 일탈적 행동을 추구하는 아웃도어레크리에이션에서 놀이성이 큰 영향을 미치는 변인임을 규명하였다고 볼 수 있다.

• 한국환경과학회지
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• 제15권10호
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• pp.913-918
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• 2006

Despite the wide distribution of air pollutants, the concentrations of indoor air pollutants may be the dominant risk factor in personal exposure due to the fact that most people spend an average of 80% of their time in enclosed buildings. Researches for improvement of indoor air quality have been developed such as installation of air cleaning device, ventilation system, titanium dioxide$(TiO_2)$ coating and so on. However, it is difficult to evaluate the magnitude of improvement of indoor air quality in field study because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. In this study, evaluation of reduction of formaldehyde and nitrogen dioxide emission rate in indoor environments by $TiO_2$ coating material was carried out using mass balance model in indoor environment. we proposed the evaluation method of magnitude of improvement in indoor air quality, considering outdoor level and ventilation. Since simple indoor concentration measurements could not properly evaluate the indoor air quality, outdoor level and ventilation should be considered when evaluate the indoor net quality.

• 대한금속재료학회지
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• 제47권10호
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• pp.652-659
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• 2009

Many ancient and historical artifacts were made by copper and its alloys. In the case of outdoor exposure artifacts, the surface could be suffered from corrosion and tarnish by the reaction with its environment. In order to preserve the artifacts, surface treatment would be needed and BTA coating has been usually applied to tin-bronze. This paper dealt with the evaluation of the properties of BTA coated film using a linear polarization method and AC impedance measurement. On the base of corrosion rate and film resistance for the specimen formed by coating process, optimum coating conditions are as follows; 3 cycles brushing or 3 cycles spraying coatings for natural dried process and 1 cycle brushing coating or 5 cycles spraying coating for hot-air dried process.

• 한국구조물진단유지관리공학회 논문집
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• 제23권6호
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• pp.18-25
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• 2019

콘크리트는 인장력에 취약한 재료적 특징을 갖기 때문에 콘크리트 구조물의 사용기간 중에 발생하는 균열은 내구성능 평가 시 필히 고려되어야 한다. 본 연구에서는 두 수준의 강도를 고려한 플라이애시 콘크리트를 배합하여 옥외 폭로 시험을 실시하였다. 노출 환경은 비말 조건으로 설정하였으며, 균열 폭이 콘크리트의 염화물 확산 거동에 미치는 영향을 평가하고자 각 배합의 시편에 0.1 mm 간격으로 최대 1.0 mm 까지의 균열 폭을 야기하였다. 그 후 3가지 수준의 노출기간(180일, 365일, 730일)을 고려하여 겉보기 염화물 확산계수 및 표면 염화물량을 산출하였다. 균열 폭의 증가에 따라 두 배합 모두 확산계수가 증가하였으며, 노출기간이 증가함에 따라 확산계수는 감소하였다. 또한 노출 기간이 증가함에 따라 균열 폭이 확산계수에 미치는 영향이 감소하였는데, 이는 염소 이온 기반 수화물이 콘크리트의 확산성을 저감시키기 때문으로 사료된다. 표면 염화물량 거동은 겉보기 염화물 확산계수 거동 대비 균열 폭의 증가에 따른 뚜렷한 변화 거동이 발생하지 않았으며, 고강도 배합에서 보통 강도 배합 대비 78.9 % ~ 90.7 %의 표면 염화물량을 나타내어 강도와의 상관관계를 갖는 것으로 판단된다.

• 한국환경보건학회지
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• 제45권6호
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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, PM_2.5) 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, PM_2.5). 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 PM_2.5 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 PM_2.5 were shown to be high indoors. Therefore, consideration of exposure assesment for each indoor pollutant and management of indoor air quality is necessary.

• 한국환경보건학회지
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• 제50권1호
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• pp.6-15
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• 2024

Background: People's activities have been restricted due to the COVID-19 pandemic. These changes in activity patterns may lead to a decrease in fine particulate matter (PM_2.5) concentrations. Additionally, the level of population exposure to PM_2.5 may be changed. Objectives: This study aimed to analyze the impact of population movement and meteorological factors on the distribution of PM_2.5 concentrations before and after the outbreak of COVID-19. Methods: The study area was Guro-gu in Seoul. The research period was selected as January to March 2020, a period of significant population movement changes caused by COVID-19. The evaluation of the dynamic population was conducted by calculating the absolute difference in population numbers between consecutive hours and comparing them to determine the daily average. Ambient PM_2.5 concentrations were estimated for each grid using ordinary kriging in Python. For the population exposure assessment, the population-weighted average concentration was calculated by determining the indoor to outdoor population for each grid and applying the indoor to outdoor ratio to the ambient PM_2.5 concentration. To assess the factors influencing changes in the ambient PM_2.5 concentration, a statistical analysis was conducted, incorporating population mobility and meteorological factors. Results: Through statistical analysis, the correlation between ambient PM_2.5 concentration and population movement was positive on both weekends and weekdays (r=0.71, r=0.266). The results confirmed that most of the relationships were positive, suggesting that a decrease in human activity can lead to a decrease in PM_2.5 concentrations. In addition, when population-weighted concentration averages were calculated and the exposure level of the population group was compared before and after the COVID-19 outbreak, the proportion of people exceeding the air quality standard decreased by approximately 15.5%. Conclusions: Human activities can impact ambient concentrations of PM_2.5, potentially altering the levels of PM_2.5 exposure in the population.