• 한국환경보건학회지
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• 제43권3호
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• pp.167-175
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• 2017

Objectives: Children may be more exposed to certain environmental contaminants because they react with greater sensitivity and have different food intakes and breathing rate per unit of body weight compared to adults. The aim of this study was to determine general exposure factors such as skin surface area, period and frequency of exposure, and others among Korean children aged ${\leq}18$ years old. This study was carried out as the first of its kind in Korea. Methods: We developed 23 recommended exposure factors for Korean children aged 0 to 18 years by reclassifying raw data from the National Health and Nutrition Examination Survey and the National Statistical Information Service, as well as through investigation by experiments in the absence of related data. Results: Reflecting the activity patterns of about 9,000 children, the daily inhalation rates for long-term exposure ranged from $9.49m^3/day$ for children from birth to <2 years to $14.98m^3/day$ for children aged 16 to <18 years. The research found that Korean children spent an average of 22.21 hours indoors, 0.67 hours outdoors, and 1.12 hours in-transit every day. Young children (${\leq}2$ years old) spent approximately 34 more minutes outdoors on weekends than they did on weekdays. Conclusion: Various physiological variables in the human body reflect characteristics of children that can directly influence risk exposure. Therefore, the identification of general exposure factors based on Korean children is required for appropriate risk assessment.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.1-7
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• 2015

The most critical health effect of lead exposure is the neurodevelopmental effect to children caused by the increased blood lead level. Therefore, the endpoint of the risk assessment for lead-contaminated sites should be set at the blood lead level of children. In foreign countries, the risk assessment for lead-contaminated sites is conducted by estimating the increased blood lead level of children via oral intake and/or inhalation (United States Environmental Protection Agency, USEPA), or by comparing the estimated oral dose to the threshold oral dose of lead, which is derived from the permissible blood lead level of children (Dutch National Institute for Public Health and the Environment, RIVM). For the risk assessment, USEPA employs Integrated-Exposure-Uptake-Biokinetic (IEUBK) Model to check whether the estimated portion of children whose blood lead level exceeds 10 µg/dL, threshold blood lead level determined by USEPA, is higher than 5%, while Dutch RIVM compares the estimated oral dose of lead to the threshold oral dose (2.8 µg/kg-day), which is derived from the permissible blood lead level of children. In Korea, like The Netherlands, risk assessment for lead-contaminated sites is conducted by comparing the estimated oral dose to the threshold oral dose; however, because the threshold oral dose listed in Korean risk assessment guidance is an unidentified value, it is recommended to revise the existing threshold oral dose described in Korean risk assessment guidance. And, if significant lead exposure via inhalation is suspected, it is useful to employ IEUBK Model to derive the risk posed via multimedia exposure (i.e., both oral ingestion and inhalation).

• 한국환경보건학회지
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• 제50권2호
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• pp.146-156
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• 2024

Background: Children who use playground facilities are exposed to potential risks due to the high concentration of heavy metals contained in the finishing materials of facilities in children's playgrounds. Objectives: The purpose of this study was to investigate the concentration of heavy metals in the finishing materials of outdoor children's playgrounds where harmful heavy metals exist in Gwangju and to conduct human risk assessment for children and adults by age to find the risks and limitations. Methods: The bottom and top layers of double-painted paint were peeled off and collected together from the finishing materials of children's play facilities such as slides, swings, and seesaws in 147 children's parks in Gwangju. Heavy metals were analyzed using ICP-OES, etc., and human risk assessment was performed using the concentrations of heavy metals. Results: Based on 1.0E-04, which requires legal regulation, CTE was found to pose a carcinogenic risk for preschool children and no carcinogenic risk for the rest of the age groups. However, RME showed that both men and women of all ages had a carcinogenic risk. For reference, when the carcinogenic risk was based on 1.0E-06, CTE was found to pose a carcinogenic risk from infants to elementary school students, and RME was found to have a carcinogenic risk in all age groups. It was judged that there is a non-carcinogenic risk if the non-carcinogenic risk exceeds 1 based on the hazard index (HI) 1. In CTE, there was no non-carcinogenic risk, and RME for preschooler males (1.49E+00) and females (1.56E+00) were found to have non-carcinogenic risk. Conclusions: This study was meaningful in that it examines the differences in the current management of heavy metals concentration standards and potential carcinogenic and non-carcinogenic risks to the human body and discusses the relationship between heavy metals and human health effects.

• 한국환경보건학회지
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• 제43권5호
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• pp.438-445
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• 2017

Objectives: The purpose of this study was to develop exposure factor data for the Korean child population, with a specific focus on behavior characteristics such as hand-to-mouth and object-to-mouth and an analysis of influential factors. Methods: We divided environments into two places, which were house/indoor and nursery. A total of 400 children (house/indoor) and a total of 162 children (nursery) were recruited from the cities of Seoul, Incheon, Daegu, and Gwangju. The children were divided into two groups. We conducted direct measurement by using one hour of videotaping alongside questionnaire surveys. This was performed to calculate behavior rates, such as how many children perform hand-to-mouth and object-to-mouth behaviors. Results: The respective average frequencies of hand-to-mouth and object-to-mouth were $0.8{\pm}2.23$ and $0.82{\pm}2.64contacts/hr$ for house/indoor. The respective average frequencies of hand-to-mouth and object-to-mouth were $2.87{\pm}4.63$ and $1.47{\pm}3.84contacts/hr$ in the nursery group. For the mouthing participants, the average frequencies of hand-to-mouth and object-to-mouth were 3.31 and 3.20 contacts/hr in house, and 4.80 and 3.26 in nursery. Compared to other countries such as the USA, the frequencies of hand-to-mouth and object-to-mouth behaviors found in this study were relatively lower. Conclusions: Children have the potential for exposure to toxic substances through non-dietary ingestion pathways by mouthing objects or their fingers. In this study, the mouthing frequency was relatively lower than that found in Western countries. This can be explained that mouthing behaviour may be affected by culture and lifestyle characteristics.

• 한국환경보건학회지
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• 제38권1호
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• pp.73-81
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• 2012

Objectives: With the goal of quantifying the risk of children contracting gastroenteritis while playing at interactive waterscape facilities and evaluating the adequacy of current water quality regulations, risk assessment was performed with Escherichia coli as pathogen. Methods: Abundances of E. coli in the waters of interactive water features in South Korea were acquired from survey reports. A gamma distribution describing the volume of water swallowed by children during swimming activities was adopted. Exposure rate and risk were calculated by Monte Carlo simulation and dose-response models for various pathogenic E. coli. Results: E. coli was detected in 25 out of 40 facilities, with range of ~1,600 CFU/100 ml. The abundance fitted an exponential distribution. Simulated exposures ranged ${\sim}1.9{\times}10^{10}$ CFU, varying greater along E. coli abundance than the volume of water. Risk of children being infected by enterohemorrhagic E. coli was high, with range of ~0.85. When E. coli abundance was <200 CFU/100 ml, which is the current government threshold, the risk decreased to <0.43. Although the guideline successfully reduced the risk of adults being infected by a less virulent E. coli strains (<0.03), the risk for children could not be quantified due to lack of dose-response models for those pathogens for children. Conclusions: Under the current guideline, children are at risk of being infected if water is contaminated with by enterohemorrhagic E. coli. For other E. coli strains, the risk appears to be considerably less. The result warrants need for developing dose-response models for children for each pathogenic E. coli strain.

• 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.

• Asian Journal of Atmospheric Environment
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• 제6권3호
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• pp.206-221
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• 2012

Hazardous chemicals can be released from artificial turf used in some school playgrounds. To distinguish between Health risk assessment (HRA) exposure scenarios for this study, the ratio of elementary, middle and high schools was considered before final selection. Considering exposure pathways (inhalational, oral and dermal), media and materials were examined, targeting hazardous chemicals released from artificial turf playground-related products. Upon evaluation, the quantity of infill chips was shown to exceed the domestic product content standard (90 mg/kg) at eight (16%) out of 50 schools. PAHs were shown to exceed standards (10 mg/kg) at two (4%) out of the 50 schools. The excess cancer risk (ECR) of carcinogens was shown to be $1{\times}10^{-6}$ in most users for the worst exposure scenario. In children with pica, who represented the most extreme exposure group, the ECR was expected to be as high as $1{\times}10^{-4}$, showing the low risk level of carcinogens. The hazard index (HI) for individual chemicals was shown to be low, at around 0.1 or less, except for children with pica, according to the mean exposure scenario of artificial turf playground exposure. However, the HI was shown to exceed 1.0 in children with pica. Therefore, no direct health risk was found in using artificial turf playgrounds and urethane flooring tracks for the mean exposure scenario, except in children with pica.

• 한국환경보건학회지
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• 제35권2호
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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.

• 한국환경보건학회지
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• 제45권2호
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• pp.113-125
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• 2019

Objectives: Although the risk assessments for nitrogen dioxide ($NO_2$) and ozone ($O_3$) have been extensively studied, most of the existing risk assessments were limited mainly to indoor environments such as workplaces, schools, and multi-use facilities. Therefore, integrated risk assessment is needed to consider exposure in all microenvironments, including outdoors. The purpose of this study was to assess the differences in risk among sub-population groups according to time-activity patterns and reported concentrations, as well as the lifetime risk of Koreans. Methods: In this study, we estimated time-weighted average exposure concentrations of $NO_2$ and $O_3$ for preschool children, students, housewives, workers, and seniors using residential time and indoor concentrations (house, school or workplace, other), outdoors, and transport by meta-analysis method. The risk for $NO_2$ and $O_3$ were assessed by hazard quotient using reference concentrations 30 and 60 ppb, respectively. The risk assessments were conducted through 1,000,000 Monte-Carlo simulations for probabilistic analysis. Results: Preschool children, students, housewives, workers, and seniors spent 91.9, 86.0, 79.8, 82.2, and 77.3% of their day in a house, school, or workplace, respectively. The risk assessment for the lifetime of a housewife and a worker showed that 33.8 and 28.4% of hazard quotients of $NO_2$ exceed 1, respectively, and more than 99% of hazard quotient of $O_3$ were less than 1. Conclusions: The risk of $NO_2$ and $O_3$ by sub-population group and for the lifetime of housewives and workers were assessed. The risk for $NO_2$ was higher than for $O_3$ and showed a different risk by sub-population group. Both $NO_2$ and $O_3$ showed a higher risk for housewives than for workers. This study can be used as a basis for lifetime exposure and risk assessment for $NO_2$ and $O_3$.

• 대한통합의학회지
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• 제7권1호
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• pp.47-56
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• 2019

Purpose: The present study confirms the content validity and understanding level of the questions of the Korean version of caries management by risk assessment (CAMBRA). Methods: To develop the Korean version of CAMBRA for children aged 0-5 years, a series of steps were followed: first, translation and reverse-translation processes were conducted by an expert committee. To establish content validity, CAMBRA was modified to adapt to the conditions in Korea by 17 dental hygiene professionals with a master's or a higher degree. The responses were analyzed using analysis of frequency and descriptive statistics. Content validity was verified by calculating the content validity index (CVI). The survey was administered to 64 mothers and caregivers to assess the understanding level of questions of the Korean version of CAMBRA. Results: Content validity of each of the items showed an S-CVI/AVE value of 0.79, but the content validities varied from 0.63 to 1.0. The understanding level of each question was between 3.56 and 4.46, thus showing favorable results. Conclusion: It was concluded that the test items verified for content validity were suitable for assessing caries risk for children of ages 0-5 years. This study would contribute to improving children's oral health and disease prevention by providing timely intervention.