• Title/Summary/Keyword: Exposure Scenarios

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Risk Assessment on Carcinogenic Pesticides of Vegetables in Korea (채소류 중 발암성 농약의 위해성 평가)

  • Yoon, Jae-Hong;Chung, Yong;Shin, Dong-Chun;Lee, Jong-Tae
    • Journal of Preventive Medicine and Public Health
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    • v.32 no.2
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    • pp.155-161
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    • 1999
  • Objectio ostinato the carcinogenic risks from the ingestion of some carcinogenic pesticides (CPs) in vegetables sampled at a local agricultural product market in Seoul. Methods: After applying a hazard identification step, we selected four pesticides, such as DDT, dieldrin, folpet, and heptachlor epoxide, for this risk assessment. Concentrations of each pesticide were measured from randomly sampled vegetables. In order to estimate the human exposure levels, we combined the concentration of pesticides in the vegetables with consumption rate of those vegetables. Three scenarios were hypothesized for human exposure assessment. Scenario I was the most conservative which supposed the undetected CPs would be the detection limit values. Scenario II was assumed that the undetected CPs would be a half of the detection limit values, and finally scenario III merely considered only values greater than the detection limit values. We finally presented the estimated carcinogenic risks on the basis of the traditional risk assessment procedure suggested by U.S. EPA. Results: Pesticides including DDT, dieldrin, folpet and heptachlor epoxide were detected in 9 samples (6%) in the range of $0.0006\sim0.09ppm$. The daily intake levels of carcinogenic pesticides were estimated in the range of $0.0009\sim0.0079{\mu}g/day$. As we expected, excess cancer risks based on scenario I was also the highest $(1.1\times10^{-8}\sim5.5\times10^{-5})$. Conclusions: We found that the estimated risks from the pesticides we investigated were not serious. We, however, propose that a continuos monitoring is needed to make sure for the protection of public health.

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Ecological Risk Assessment of Chemicals Migrated from a Recycled Plastic Product

  • Roh, Ji-Yeon;Kim, Min-Hyuck;Kim, Woo Il;Kang, Young-Yeul;Shin, Sun Kyoung;Kim, Jong-Guk;Kwon, Jung-Hwan
    • Environmental Analysis Health and Toxicology
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    • v.28
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    • pp.13.1-13.5
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    • 2013
  • Objectives: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. Methods: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals - di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)-were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. Results: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were $1.0{\times}10^{-4}$, $1.2{\times}10^{-5}$, $9.5{\times}10^{-3}$, and $5.3{\times}10^{-3}mg/L$ for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were $5.2{\times}10^{-3}$, $6.0{\times}10^{-4}$, $5.0{\times}10^{-1}$, and $2.7{\times}10^{-1}mg/kg$ for DEHP, DINP, Cd, and Pb, respectively. Conclusions: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.

Misclassification Adjustment of Family History of Breast Cancer in a Case-Control Study: a Bayesian Approach

  • Moradzadeh, Rahmatollah;Mansournia, Mohammad Ali;Baghfalaki, Taban;Ghiasvand, Reza;Noori-Daloii, Mohammad Reza;Holakouie-Naieni, Kourosh
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8221-8226
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    • 2016
  • Background: Misreporting self-reported family history may lead to biased estimations. We used Bayesian methods to adjust for exposure misclassification. Materials and Methods: A hospital-based case-control study was used to identify breast cancer risk factors among Iranian women. Three models were jointly considered; an outcome, an exposure and a measurement model. All models were fitted using Bayesian methods, run to achieve convergence. Results: Bayesian analysis in the model without misclassification showed that the odds ratios for the relationship between breast cancer and a family history in different prior distributions were 2.98 (95% CRI: 2.41, 3.71), 2.57 (95% CRI: 1.95, 3.41) and 2.53 (95% CRI: 1.93, 3.31). In the misclassified model, adjusted odds ratios for misclassification in the different situations were 2.64 (95% CRI: 2.02, 3.47), 2.64 (95% CRI: 2.02, 3.46), 1.60 (95% CRI: 1.07, 2.38), 1.61 (95% CRI: 1.07, 2.40), 1.57 (95% CRI: 1.05, 2.35), 1.58 (95% CRI: 1.06, 2.34) and 1.57 (95% CRI: 1.06, 2.33). Conclusions: It was concluded that self-reported family history may be misclassified in different scenarios. Due to the lack of validation studies in Iran, more attention to this matter in future research is suggested, especially while obtaining results in accordance with sensitivity and specificity values.

Cue-Exposure Therapy using Virtual Reality for alcohol Addicts (가상현실을 이용한 알코올중독자의 단서노출 치료)

  • Kwon, Hyo-Seok;Roh, Sung-Won;Choi, Joon-Ho;Yang, Byung-Hwan;Lee, Jang-Han
    • 한국HCI학회:학술대회논문집
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    • 2006.02b
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    • pp.639-645
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    • 2006
  • During abstinence from alcohol, craving is elicited by the cues and contexts previously associated with alcohol, and contributes to relapse. To prevent the craving and relapse experienced by alcoholics, cue-exposure therapy (CET) has been used to extinguish the association between alcohol and alcohol-related cues and contexts. This study applied CET, using a virtual reality (VR) system, to eight members of an Alcoholics Anonymous group, in eight sessions. Cues and contexts most likely to elicit an urge to drink were selected through a preliminary survey in order to compose VR-CET scenarios: a glass, bottle, food, and a bar were judged to be the most tempting for people in alcohol dependence and abstinence. By these cues and contexts, a Japanese style pub and a western bar were composed. Each session was administered for 30 minutes by a psychiatrist and included an introduction, immersion, VR navigation, interviews about feelings, and self-report questionnaires about cravings. The eight sessions consisted of initial and closing sessions, and six cue- and context-focused sessions. As a result, a reduction in cue-elicited craving after VR-CET was reported. A mean score of 15.75 (SD = 10.91) on the Alcohol Urge Questionnaire in the first session decreased to 11.57 (SD = 6.88) in the final session.

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A Sensitivity Study on Nuclide Release from the Near-field of a Pyroprocessed Waste Repository System: Part 2. A Deterministic Approach (파이로처리 폐기물 처분 시스템 근계 영역 내 핵종 유출 민감도: 제 2 부 결정론적 접근)

  • Lee, Youn-Myoung;Jeong, Jongtae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.1
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    • pp.37-43
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    • 2014
  • A parametric sensitivity to the annual exposure dose rate to the farming exposure group has been deterministically carried out for three principal elements identified in the near-field of the pyroprocessed waste repository system as a series study of Part 1 of the coupled paper with the same title. Credit time for both metal and ceramic containers, annual nuclide release rete and the degree of loss of bentonite buffer around the container are selected and investigated deterministically for important nuclides. To this end the A-KRS has been assessed and then compared among each other with the normal, the worst, and the best case scenarios associated with their extreme values these elements could have. All the elements are shown to be sensitive to the results as was in Part 1. Methodology studied through this study and the results are expected to make a good feedback to the repository design.

A study of asbestos risk at some naturally occurring asbestos areas, Korea (우리나라 일부 자연발생석면 발생가능지역의 석면 위해도에 관한 연구)

  • Jung, Joon Sig;Shim, In Keun;Jung, Hyen Sung;Lee, Kyu Mok;Kim, Seong Mi;Kwon, Myung Hee;Chung, Hyen Mi
    • Journal of odor and indoor environment
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    • v.17 no.4
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    • pp.330-336
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    • 2018
  • The objective of this study was to determine whether crops and fruits absorb the naturally occurring asbestos (NOA). The concentration of asbestos in various crops and fruits grown in NOA areas was analyzed and background levels of asbestos in ambient air and soil samples were assessed. Actinolite/Tremolite asbestos were detected in all soil samples. Among 21 ambient air samples, 2 samples were recorded to contain 0.0005 f/cc (fiber per cubic centimeter) but no asbestos was detected in the other samples using transmission electron microscopy (TEM). However, no evidence suggesting that the crops and fruits could be contaminated by NOA was found in this study. The excess lifetime cancer risks (ELCRs) of ABS scenarios (agricultural activities) used in this study were calculated by using the Arithmetic (AM) and Geometric mean (GM) of ELCRs. The AM and GM of ELCRs estimated from digging soil and weeding activities did not exceed $1{\times}10^{-4}$, which was defined as the general acceptable risk range for exposure. The results of this study would be informative to NOA managers and related policy makers to make plans to prevent unexpected exposure to asbestos to residents living in an NOA area.

Risk Assessment of Arsenic-Contaminated Groundwater in Multiple Scenarios in a Rural Area of Gyeongnam Province, Korea (경남 농촌 지역 비소 오염 지하수의 시나리오별 위해성 평가)

  • Oh, Serim;Lee, Jin-Yong;Moon, Sang-Ho;Jang, Jiwook;Jeong, Eunju
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.437-448
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    • 2022
  • This work aims to assess the threat to human health of hazardous materials in groundwater that is used domestically and for drinking. Two distinct sub-assessments are considered: cancer and non-cancer risk. The studied groundwater is in an agricultural area of Gyeongnam Province, Korea, and is contaminated by arsenic at a mean level of 16.27 ㎍/L, far greater than the WHO guideline (10 ㎍/L for drinking water). We collected groundwater data from the National Groundwater Information Center (gims.go.kr) and assessed the risk to human health following the methodology of the United States Environmental Protection Agency. We considered three exposure scenarios: domestic use (scenario 1) and drinking use with different doses (scenarios 2 and 3). Scenario 1 had a median hazard quotient (HQ) of 0.77 and a cancer risk (CR) of 0.013. Scenario 2 had a median HQ of 0.08 and a CR of 3.69 × 10-5, and the values for scenario 3 were 0.11 and 4.82 × 10-5, respectively. Scenario 1 is likely the most hazardous to human health. Further study of the origin of arsenic in groundwater in the study area is required, as are remedial measures to mitigate its health effects.

A Feasibility Study for Decision-Making Support of a Radioactive Contamination Model in an Urban Environment (METRO-K) (도시환경 방사능오염 평가모델 METRO-K의 대응행위 결정지원을 위한 실용성 연구)

  • Hwang, Won-Tae;Han, Moon-Hee;Jeong, Hyo-Joon;Kim, Eun-Han;Lee, Chang-Woo
    • Journal of Radiation Protection and Research
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    • v.33 no.1
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    • pp.27-34
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    • 2008
  • A Korean urban contamination model METRO-K (${\underline{M}}odel$ for ${\underline{E}}stimates$ the ${\underline{T}}ransient$ Behavior of ${\underline{R}}adi{\underline{O}}active$ Materials in the ${\underline{K}}orean$ Urban Environment, which is capable of calculating the exposure doses resulting from radioactive contamination in an urban environment, is taking part in a model testing program EMRAS (${\underline{E}}nvironmental$ ${\underline{M}}odelling$ for ${\underline{RA}}diation$ ${\underline{S}}afety$) oragnized by the IAEA (${\underline{I}}nternational$ ${\underline{A}}tomic$ ${\underline{E}}nergy$ ${\underline{A}}gency$). For radioactive contamination scenarios of Pripyat districts and a hypothetical RDD (${\underline{R}}adiological$ ${\underline{D}}ispersal$ ${\underline{D}}evice$), the predicted results using METRO-K were submitted to the EMRAS's Urban Contamination Working Group. In this paper, the predicted results for the contamination scenarios of a Pripyat district were shown in case of both without remediation measures and with ones. Comparing with the predictied results of the models that have taken part in EMRAS program, a feasibility for decision-making support of METRO-K was investigated. As a predicted result of METRO-K, to take immediately remediation measures following a radioactive contamination, if possible, might be one of the best ways to reduce exposure dose. It was found that the discrepancies of predicted results among the models are resulted from 1) modeling approaches and applied parameter values, 2) exposure pathways which are considered in models, 3) assumptions of assessor such as contamination surfaces which might affect to an exposure receptor and their sizes, 4) parameter values which are related with remediation measures applied through literature survey. It was indentified that a Korean urban contamination model METRO-K is a useful tool for dicision-making support through the participation of EMRAS program.

External dose assessment for workers dismantling the bio-shield of a commercial power nuclear reactor: Case study of Kori-1, Korea

  • Lee, ChoongWie;Lee, Donghyun;Kim, Hee Reyoung;Lee, Seung Jun
    • Nuclear Engineering and Technology
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    • v.52 no.9
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    • pp.2085-2091
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    • 2020
  • The license for Kori-1, the first commercial reactor in Busan, Korea, was terminated in June 2017; therefore, preparations are being made for its decommissioning. Because the radioactivity of Bio-shield varies greatly throughout the structure, the doses received by the workers depend on the location, order, and duration of dismantling operations. Thus, a model for evaluating the worker external dose during the dismantling of the Kori-1 bio-shield was developed, and work scenarios for dose assessment were designed. The Dose evaluation code VISIPLAN was used for dose assessment. The dose rate around the bio-shield was evaluated and the level of exposure to the operator was evaluated according to the work scenario. The maximum annual external dose was calculated as 746.86 mSv for a diamond wire saw operator under dry cutting conditions, indicating that appropriate protective measures, such as changing dismantling sequence, remote monitoring, shield installation, and adjustment of work team are necessary for the safe dismantling of the bio-shield. Through these protective measures, it was found that the worker's dose could be below the dose limit.

Estimating Freshwater Fish Intake for Human Health Risk Assessment Using Korea National Health and Nutrition Examination Survey (국민건강영양조사를 활용한 담수어패류 섭취량 산정: 위해성 평가를 위한 파라메타 도출)

  • Kwak, Jin Il;Oh, Kyungwon;Kweon, Sanghui;An, Youn-Joo
    • Journal of Korean Society on Water Environment
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    • v.29 no.2
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    • pp.165-169
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    • 2013
  • Freshwater fish intake is a critical parameter for deriving water quality criteria and water quality standards for protection of human health based on human health risk assessment. Although the freshwater fish intake parameter should be accurate and representative of Korean fish consumption for the water quality criteria to be reliable, data are limited in Korea and have low reliability. In this study, Korean National Health and Nutrition Examination Survey data from 2008-2010 were analyzed to reevaluate freshwater fish consumption. Based on these results, an average consumption rate of 3.0 g/day per person, a $90^{th}$ percentile consumption rate of 0.0 g/day per person, an average consumption rate of 65.7 g/day per fish consumer, and a $90^{th}$ percentile consumption rate of 153.4 g/day per fish consumer were proposed for derivation of water quality criteria using a conservative approach and various exposure scenarios.