• 한국환경보건학회지
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• 제39권6호
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• pp.532-540
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• 2013

Background: Exposure factors for consumer products have been developed since the 1980s. Such exposure factors are important in risk assessment. Since the exposure/use patterns of consumer products in a country may reflect its respective cultural, meteorological, and socio-economic circumstances, unique Korean exposure factors for consumer products are needed. Such exposure factors are required for newly-enacted chemical regulations in Korea. For this review, published papers and survey reports on exposure factors of consumer products were examined for their assessment methodologies. Results: Investigation into exposure factors for consumer products used a variety of methods: home visit, online, telephone, and mail surveys using questionnaires; face to face interviews; modeling using a constructed database; and direct measurement. To collect more accurate exposure information or to check the reliability of the sampling method, some studies were repeated using the same questionnaire, in-home observation, direct measurement of usage, and videotaping. In Korea, nationwide exposure surveys were conducted five times over five years to obtain Korean exposure factors. However, with the exception of the $5^{th}$-year study, the surveys were online questionnaires and only the $5^{th}$-year study validated the accuracy of exposure information by re-visits and direct measurement. Conclusion: Accurate exposure factors are an essential part of risk assessment to assure safe use of consumer products. For better and safer management of consumer products, accurate exposure factors in Korea should be assessed for various exposure pathways.

• 한국환경보건학회지
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• 제43권2호
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• pp.157-166
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• 2017

Objectives: Exposure to hazardous air pollutants could be affected by sociodemographic factors such as age, gender and more. Information on time spent in microenvironments has a critical role in exposure assessment. The purpose of this study was to analyze the exposure pathways which influence personal exposure through time-activity patterns and sociodemographic factors. Methods: A total of 379 subjects were collected from the second term of the Korean National Environmental Health Survey. A questionnaire survey in relation to sociodemographic factors and a time-activity diary were carried out for personal exposure to toluene. Focusing on personal exposure to toluene, factors affecting personal exposure were analyzed using multiple regression analysis. Results: Participants spent their time in an indoor house for $16.8{\pm}4.0hr$, workplace or school $2.3{\pm}3.5hr$, and other indoor $2.1{\pm}2.2hr$. Sociodemographic factors were significantly different among each personal exposure and microenvironment. Time of staying at an office turned out to be a main factor from point of exposure in exposure pathway using multiple regression analysis. As a result, this means that exposure may be different according to the time of staying in each microenvironment. Conclusions: Personal exposure to air pollutants might be decided by time-activity pattern indicating when, where, and which activities people pursue, as well as individual sociodemographic factors.

• 방사성폐기물학회지
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• 제19권1호
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• pp.123-132
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• 2021

Radiological impact analyses were carried out for a near-surface radioactive waste repository at Gyeongju in South Korea. The RESRAD-ONSITE code was applied for the estimation of maximum exposure doses by considering various exposure pathways based on a land area of 2,500 ㎡ with a 0.15 m thick contamination zone. Typical influencing input parameters such as shield depth, shield materials' density, and shield erosion rate were examined for a sensitivity analysis. Then both residential farmer and industrial worker scenarios were used for the estimation of maximum exposure doses depending on exposure duration. The radiation dose evaluation results showed that 60Co, 137Cs, and 63Ni were major contributors to the total exposure dose compared with other radionuclides. Furthermore, the total exposure dose from ingestion (plant, meat, and milk) of the contaminated plants was more significant than those assessed for inhalation, with maximum values of 5.5×10-4 mSv·yr-1 for the plant ingestion. Thus the results of this study can be applied for determining near-surface radioactive waste repository conditions and providing quantitative analysis methods using RESRAD-ONSITE code for the safety assessment of disposing radioactive materials including decommissioning wastes to protect human health and the environment.

• Annals of Pediatric Endocrinology and Metabolism
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• 제23권4호
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• pp.182-195
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• 2018

Increasing prevalence of childhood obesity poses threats to the global health burden. Because this rising prevalence cannot be fully explained by traditional risk factors such as unhealthy diet and physical inactivity, early-life exposure to endocrine disrupting chemicals (EDCs) is recognized as emerging novel risk factors for childhood obesity. EDCs can disrupt the hormone-mediated metabolic pathways, affect children's growth and mediate the development of childhood obesity. Many organic pollutants are recently classified to be EDCs. In this review, we summarized the epidemiological and laboratory evidence related to EDCs and childhood obesity, and discussed the possible mechanisms underpinning childhood obesity and early-life exposure to non-persistent organic pollutants (phthalates, bisphenol A, triclosan) and persistent organic pollutants (dichlorodip henyltrichloroethane, polychlorinated biphenyls, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances). Understanding the relationship between EDCs and childhood obesity helps to raise public awareness and formulate public health policy to protect the youth from exposure to the harmful effects of EDCs.

• Journal of Radiation Protection and Research
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• 제10권1호
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• pp.50-63
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• 1985

농축인자법(濃縮因子法)(Concentration Factor Method)을 이용(利用)하여 결정피폭경로(決定被曝經路)를 분석(分析)한 후(後) 표준원전(標準原電)의 기체상방사성대기방출물(氣體狀放射性大氣放出物)에 대한 유도방출한도(誘導放出限度)(Derived Release Limits, DRL's)를 계산(計算)하였다. 이 방출한도(放出限度)는 핵시설(核施設) 주변(周邊)의 결정군구성개인(決定群構成個人)에 대(對)한 방사선(放射線) 피폭(被曝)을 관련피폭한도이하(關聯被曝限度以下)로 유지(維持)시키는 양(量)이다 본(本) 연구(硏究)에서는 1985년(年) 초(初) 미국(美國)의 환경보호청(環境保護廳)(EPA)에서 새로 권고(勸告)한 피폭한도(被曝限度)를 채택(採擇)하여 계산(計算)을 수행(遂行)하였다. 유도방출한도(誘導放出限度)(DRL)의 계산(計算)은 미국(美國)의 원자력(原子力) 규제위원회(規制委員會)(USNRC)가 규제지침(規制指針)(Reg. Guide) 1.109에서 제시(提示)하고 있는 선양평가(線量評價)모델을 표준(標準)모델로 사용(使用)하여 수행(遂行)하였으나, 동(同) 모델의 피폭경로분석(被曝經路分析)에서 우유(牛乳) 및 육류(肉類)의 섭취경로(攝取經路)는 국내(國內)의 현실상(現實狀) 무시가능(無視可能)한 것으로 고려(考慮)하여 본(本) 연구(硏究)에서 제외(除外)시켰다. 계산(計算)에서 고려(考慮)한 방출선원항(放出線源項)은 희유기체(稀有氣體), 요오드, 입자상원소(粒子狀元素) 및 삼중수소기체(三重水素氣體)였으며, 방출원(放出源)에서 북(北)쪽으로 1.3 km 거리에 위치(位置)하고 있는 주민영구거주지역(住民永久居住地域)을 대상(對象)으로 계산(計算)을 수행(遂行)하였다. 본(本) 연구(硏究)에서는 표준원전(標準原電)의 대상(對象)으로 고리원전(古里原電) 1호기(號機)를 선정(選定)하여 동원전(同原電)의 연간방출(年間放出)에 대(對)한 유도한도(誘導限度)를 계산(計算)하였으며, 1982년도(年度)의 실방출률(實放出率)과 비교(比較) 검토(檢討)하였다. 검토결과(檢討結果), 고리원전(古里原電) 1호기(號機)의 1982년도(年度)의 실방출률(實放出率)은 본(本) 연구(硏究)에서 구(求)해진 유도방출한도(誘導放出限度)보다 낮았으며, 방출물(放出物)에 의한 시설주변(施設周邊) 개인(個人)의 년간피폭선량(年間被曝線量)은 EPA에서 권고(勸告)하는 피폭한도이하(被曝限度以下)로 유지(維持)되었음을 알 수 있었다. 또한 본(本) 연구(硏究)에서 가장 결정적(決定的)인 피폭경로(被曝經路)는Co-60와 Cs-137과 같은 입자상침적방사핵종(粒子狀沈積放射核種)으로 오염(汚染)된 토양(土壤)에 의한 전신외부(全身外部) 피폭경로(被曝經路)였다.

• Journal of Microbiology and Biotechnology
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• 제32권6호
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• pp.699-708
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• 2022

Antibiotic exposure during pregnancy have an adversely effects on offspring behavior and development. However, its mechanism is still poorly understood. To uncover this, we added ceftriaxone sodium to the drinking water of rats during pregnancy and conducted three-chamber sociability test, open-field test, and Morris water maze test in 3- and 6-week-old offspring. The antibiotic group offspring showed lower sociability and spatial learning and memory than control. To determine the role of the gut microbiota and their metabolites in the changes in offspring behavior, fecal samples of 6-week-old offspring rats were sequenced. The composition of dominant gut microbial taxa differed between the control and antibiotic groups. KEGG pathway analysis showed that S24-7 exerted its effects through the metabolic pathways including mineral absorption, protein digestion and absorption, Valine, leucine, and isoleucine biosynthesis. Correlation analysis showed that S24-7 abundance was negatively correlated with the level of VEGF, and metabolites associated with S24-7-including 3-aminobutanoic acid, dacarbazine, L-leucine, 3-ketosphinganine, 1-methylnicotinamide, and N-acetyl-L-glutamate-were also significantly correlated with VEGF levels. The findings suggest that antibiotic exposure during pregnancy, specifically ceftriaxone sodium, will adversely affects the behavior of offspring rats due to the imbalance of gut microbiota, especially S24-7, via VEGF and various metabolic pathways.

• 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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• 제47권5호
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• pp.454-461
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• 2021

Background: Fish and fishery products (FFPs) unintentionally contaminated with various environmental pollutants are major exposure pathways for humans. To protect human health from the consumption of contaminated FFPs, it is essential to develop a systematic tool for evaluating exposure and risks. Objectives: To regularly, accurately, and quickly evaluate adverse health outcomes due to FFPs contamination, we developed an automated dietary exposure and risk assessment system called HERA (the Human Exposure and Risk Assessment system for chemicals in FFPs). The aim of this study was to develop an overall architecture design and demonstrate the major features of the HERA system. Methods: For the HERA system, the architecture framework consisted of multi-layer stacks from infrastructure to fish exposure and risk assessment layers. To compile different contamination levels and types of seafood consumption datasets, the data models were designed for the classification codes of FFP items, contaminants, and health-based guidance values (HBGVs). A systematic data pipeline for summarizing exposure factors was constructed through down-scaling and preprocessing the 24-hour dietary recalls raw dataset from the Korea National Health and Nutrition Examination Survey (KNAHES). Results: According to the designed data models for the classification codes, we standardized 167 seafood items and 2,741 contaminants. Subsequently, we implemented two major functional workflows: 1) preparation and 2) main process. The HERA system was developed to enable risk assessors to accumulate the concentration databases sustainably and estimate exposure levels for several populations linked to seafood consumption data in KNAHES in a user-friendly manner and in a local PC environment. Conclusions: The HERA system will support policy-makers in making risk management decisions based on a nation-wide risk assessment for FFPs.

• Journal of Ginseng Research
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• 제35권3호
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• pp.339-343
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• 2011

Polycyclic aromatic hydrocarbons (PAHs) are well known environmental carcinogens. PAH metabolites, especially BaP-7,8- dihydrodiol, 9,10 epoxide, initiate carcinogenesis via high specificity binding to DNA to form DNA adducts. The Korean red ginseng (KRG) from Panax ginseng has been suggested to protect against damages due to PAH exposure but the mechanism is unknown. Therefore, we investigated effects of KRG on PAH exposure using toxicokinetic methods and changes of PAH-induced oxidative damage during a 2 week-clinical trial (n=21 healthy young female, $23.71{\pm}2.43$ years). To analyze antioxidative effects of KRG, we measured changes in the levels of urinary malondialdehyde (MDA) before and after KRG treatment. We observed a significant positive association between levels of urinary MDA and 1-hydroxypyrene, a biomarker of PAH exposures (slope=1.47, p=0.03) and confirmed oxidative stress induced by PAH exposures. A reverse significant correlation between KRG treatment and level of urinary MDA was observed (p=0.03). In summary, results of our clinical trial study suggest that KRG plays a significant role in antioxidative as well as toxicokinetic pathways against PAHs exposure.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.837-842
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• 2019

A large amount of radioactive material was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) in 2011 and dispersed into the environment. Though seven years have passed since the Fukushima Daiichi Nuclear Power Plant accident, some parts of Japan are still under the influence of radionuclide contamination, especially Fukushima Prefecture and prefectures neighboring Fukushima Prefecture. The long-term effective doses and the contributions of each exposure pathway (5 exposure pathways) and radionuclide ($^{131}I$, $^{134}Cs$, and $^{137}Cs$) were evaluated for people living in the regions of Fukushima and neighboring prefectures in Japan using a developed dose assessment code system with Japanese specific input data. The results estimated in this study were compared with data from previously published reports. Groundshine and ingestion were predicted to contribute most significantly to the total long-term dose for all regions. The contributions of each exposure pathway and radionuclide show different patterns for certain regions of Japan.