• 한국환경보건학회지
• /
• 제48권2호
• /
• pp.59-65
• /
• 2022

Background: Since people move through microenvironments rather than staying in one place, they may be exposed to both indoor and outdoor PM_2.5 concentrations. Objectives: The aim of this study was to assess the exposure level of each sub-population group and evaluate the contribution rate of the major microenvironments. Methods: Exposure scenarios for sub-population groups were constructed on the basis of a 2019 Time-Use survey and the previous literature. A total of five population groups were classified and researchers wearing MicroPEM simulated monitoring PM_2.5 exposure concentrations in real-time over three days. The exposure contribution for each microenvironment were evaluated by multiplying the inhalation rate and the PM_2.5 exposure concentration levels. Results: Mean PM_2.5 concentrations were 33.0 ㎍/m³ and 22.5 ㎍/m³ in Guro-gu and Wonju, respectively. When the exposure was calculated considering each inhalation rate and concentration, the home showed the highest exposure contribution rate for PM_2.5. As for preschool children, it was 90.8% in Guro-gu, 94.1% in Wonju. For students it was 65.3% and 67.3%. For housewives it was 98.2% and 95.8%, and 59.5% and 91.7% for office workers. Both regions had higher exposure to PM_2.5 among the elderly compared to other populations, and their PM_2.5 exposure contribution rates were 98.3% and 94.1% at home for Guro-gu and Wonju, respectively. Conclusions: The exposure contribution rate could be dependent on time spent in microenvironments. Notably, the contribution rate of exposure to PM_2.5 at home was the highest because most people spend the longest time at home. Therefore, microenvironments such as home with a higher contribution rate of exposure to PM_2.5 could be managed to upgrade public health.

• 한국환경보건학회지
• /
• 제47권6호
• /
• pp.521-529
• /
• 2021

Background: The coronavirus disease (COVID-19) has caused changes in human activity, and these changes may possibly increase or decrease exposure to fine dust (PM_2.5). Therefore, it is necessary to evaluate the exposure to PM_2.5 in relation to the outbreak of COVID-19. Objectives: The purpose of this study was to compare and evaluate the exposure to PM_2.5 concentrations by the variation of dynamic populations before and after the outbreak of COVID-19. Methods: This study evaluated exposure to PM_2.5 concentrations by changes in the dynamic population distribution in Guro-gu, Seoul, before and after the outbreak of COVID-19 between Jan and Feb, 2020. Gurogu was divided into 2,204 scale standard grids of 100 m×100 m. Hourly PM_2.5 concentrations were modeled by the inverse distance weight method using 24 sensor-based air monitoring instruments. Hourly dynamic population distribution was evaluated according to gender and age using mobile phone network data and time-activity patterns. Results: Compared to before, the population exposure to PM_2.5 decreased after the outbreak of COVID-19. The concentration of PM_2.5 after the outbreak of COVID-19 decreased by about 41% on average. The variation of dynamic population before and after the outbreak of COVID-19 decreased by about 18% on average. Conclusions: Comparing before and after the outbreak of COVID-19, the population exposures to PM_2.5 decreased by about 40%. This can be explained to suggest that changes in people's activity patterns due to the outbreak of COVID-19 resulted in a decrease in exposure to PM_2.5.

• 한국환경보건학회지
• /
• 제48권6호
• /
• pp.298-305
• /
• 2022

Background: The concentration of air pollutants as measured by the Air Quality Monitoring System (AQMS) is not an accurate population exposure level since actual human activities and temporal and spatial variability need to be considered. Therefore, to increase the accuracy of exposure assessment, the population should be considered. However, it is difficult to obtain population data due to limitations such as personal information. Objectives: The existing population defined in this study is the number of people in each region's grid. The purpose is to provide a methodology for evaluating exposure to PM_2.5 through existing population data provided by the National Geographic Information Institute. Methods: The selected study period was from October 26 to October 28, 2021. Using PM_2.5 concentration data measured at the Sensor-based Air Monitoring Station (SAMS) installed in Guro-gu and Wonju-si, the concentration for each grid was estimated by applying inverse distance weights through QGIS version 3.22. Considering the existing population, population-weighted average concentration (PWAC) was calculated and the exposure level of the population was compared by region. Results: The outdoor PM_2.5 concentration as measured through the SAMS was high in Wonju-si on all three days. Wonju-si showed an average 22% higher PWAC than Guro-gu. As a result of comparing the PWAC and outdoor PM_2.5 concentration by region, the PWAC in Guro-gu was 1~2% higher than the observed value, but it was almost the same. Conversely, observations of Wonju-si were 10.1%, 11.3%, and 8.2% higher than PWAC. Conclusions: It is expected that the Geographic Information System (GIS) method and the existing population will be used to evaluate the exposure level of a population with a narrow activity radius in further research. In addition, based on this study, it is judged that research on exposure to environmental pollutants and risk assessment methods should be expanded.

• 한국환경보건학회지
• /
• 제49권5호
• /
• pp.262-274
• /
• 2023

Background: Exposure levels for heavy metals such as lead (Pb), mercury (Hg), and cadmium (Cd) have increased due to human activities. They are known to be a public health concern. Objectives: This study aimed to determine the exposure levels to heavy metals in the blood and urine of South Korean adults and to present the contribution rate of exposure pathways using an exposure algorithm for men aged 19~64, women aged 19~64, and all seniors aged 65 or older. Methods: We analyzed data from the Korean National Environmental Health Survey (KoNEHS) Cycle 4 (2018~2020). A total of 2,646 participants aged ≥19 years were included. Multiple regression analysis was performed to determine the factors affecting heavy metal concentrations. The contribution rate was calculated by applying three exposure algorithms for ingestion, inhalation, and dermal exposure. Results: Factors that commonly affect heavy metal concentrations in blood and urine were gender and age. The main influencing factors for Pb and Cd were education level and smoking status, while frequency of fish consumption and of alcohol consumption were indicated to be the main influencing factors for mercury. The contribution rates of lead and cadmium from food ingestion were 78.03~79.62% and 88.39~92.89%, respectively. Additionally, the highest contribution for mercury was accounted for by food at 81.69~85.77%. As a result of the risk assessment, cadmium was found to pose a potential health risk a with total cancer risk (TCR) of more than 1×10^-6. Conclusions: The KoNEHS could be an important study for determining the level of exposure to heavy metals and their influencing factors. Integrated exposure to heavy metals could assess the main exposure pathways, and this methodology could be applied to exposure management of heavy metals.

• 한국환경보건학회지
• /
• 제50권1호
• /
• pp.6-15
• /
• 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.

• 초등상담연구
• /
• 제11권1호
• /
• pp.71-91
• /
• 2012

본 연구는 학교 부적응 아동을 대상으로 동시를 활용한 상담 프로그램을 실시하여 자아존중감과 학교적응에서 어떤 효과가 나타나는지 밝히는데 그 목적이 있다. 이를 위하여 동시를 활용한 상담 프로그램을 개발하고 연구문제를 다음과 같이 설정하였다. 첫째, 동시를 활용한 상담 프로그램이 학교 부적응 아동의 자아존중감 향상에 미치는 영향은 어떠한가? 둘째, 동시를 활용한 상담 프로그램이 학교 부적응 아동의 학교적응에 미치는 영향은 어떠한가? 연구 대상은 사전검사, 현재 담임 부모님 친구의 의견을 반영하여 학교 부적응 아동으로 판정된 2명의 초등학교 4학년생이다. 주 2회 40분간 12회기에 걸쳐 동시를 활용한 상담프로그램을 상담에 적용하며 내담자의 변화과정을 탐색하였다. 즉 상담과정에서 대상 아동이 반응한 언어와 행동을 평가한 결과와 부모 친구 교사의 심층면담, 행동관찰평가표, 측정 도구의 사전 사후검사 결과를 비교하여 자료를 수집하였고, 연구자가 개발한 동시를 활용한 상담 프로그램의 효과를 탐색하였다. 연구결과는 다음과 같다. 첫째, 동시를 활용한 상담 프로그램은 학교 부적응 아동의 가정적, 사회적, 학업적 자아존중감을 향상시켰다. 둘째, 교사관계, 교우관계, 수업태도 등 학교적응에서도 긍정적인 변화를 보였다. 그 외에도 동시를 활용한 상담 프로그램의 독서자료인 동시가 상담과정에서 효과적으로 작용하였음을 밝혔다. 동시 낭송과 동시 내용이 내담자의 자기개방을 촉진하여 상담자와의 관계 개선에 긍정적인 영향을 미쳤고 상담이 효과적으로 진행될 수 있도록 이끄는 매개체 역할을 하였다.