• Title/Summary/Keyword: Probabilistic exposure assessment

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Proposed Approach of Korean Ecological Risk Assessment for the Derivation of Soil Quality Criteria (토양준거치 도출을 위한 국내형 생태위해성평가기법 제안)

  • An, Youn-Joo;Lee, Woo-Mi;Nam, Sun-Hwa;Jeong, Seung-Woo
    • Journal of Soil and Groundwater Environment
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    • v.15 no.3
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    • pp.7-14
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    • 2010
  • Ecological Risk Assessment (ERA) supports a decision-making process such as establishment of environmental quality criteria. Soil quality criteria (SQC) are essential to protect soil organisms from the exposure to various soil contaminants. In this study, ERA methodologies of advanced countries for soil pollution were extensively compared to propose the ERA approach suitable for soil ecosystem in Korea. The soil ERAs in European Chemical Bureau(ECB), The Netherlands, and Canada can be classified as deterministic ecological risk assessment (DERA), and probabilistic ecological risk assessment (PERA) based on species sensitivity distribution (SSD). We propose three ERA methods according to abundance and reliability of soil ecotoxicity data. The method considered land use such as residential/agricultural, and industrial/commercial uses. The taxonomic groups of soil organism were classified as 'Class' level including different trophic levels (Magnoliopsida or Liliopsida, Clitellata, and Insecta or Secernentea). This study can be used to estimate the soil quality criteria to protect soil biota.

Development of MURCC code for the efficient multi-unit level 3 probabilistic safety assessment

  • Jung, Woo Sik;Lee, Hye Rin;Kim, Jae-Ryang;Lee, Gee Man
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2221-2229
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    • 2020
  • After the Fukushima Daiichi nuclear power plant (NPP) accident, level 3 probabilistic safety assessment (PSA) has emerged as an important task in order to assess the risk level of the multi-unit NPPs in a single nuclear site. Accurate calculation of the radionuclide concentrations and exposure doses to the public is required if a nuclear site has multi-unit NPPs and large number of people live near NPPs. So, there has been a great need to develop a new method or procedure for the fast and accurate offsite consequence calculation for the multi-unit NPP accident analysis. Since the multi-unit level 3 PSA is being currently performed assuming that all the NPPs are located at the same position such as a center of mass (COM) or base NPP position, radionuclide concentrations or exposure doses near NPPs can be drastically distorted depending on the locations, multi-unit NPP alignment, and the wind direction. In order to overcome this disadvantage of the COM method, the idea of a new multiple location (ML) method was proposed and implemented into a new tool MURCC (multi-unit radiological consequence calculator). Furthermore, the MURCC code was further improved for the multi-unit level 3 PSA that has the arbitrary number of multi-unit NPPs. The objectives of this study are to (1) qualitatively and quantitatively compare COM and ML methods, and (2) demonstrate the strength and efficiency of the ML method. The strength of the ML method was demonstrated by the applications to the multi-unit long-term station blackout (LTSBO) accidents at the four-unit Vogtle NPPs. Thus, it is strongly recommended that this ML method be employed for the offsite consequence analysis of the multi-unit NPP accidents.

Preliminary Post-closure Safety Assessment of Disposal System for Disused Sealed Radioactive Source (폐밀봉선원 처분시스템 예비 폐쇄후 안전성평가)

  • Lee, Seunghee;Kim, Juyoul
    • Journal of Soil and Groundwater Environment
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    • v.22 no.4
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    • pp.33-48
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    • 2017
  • An optimum disposal plan of disused sealed radioactive sources (DSRSs) should be established to ensure long-term disposal safety at the low- and intermediate-level radioactive waste (LILW) disposal facility in Gyeongju. In this study, an optimum disposal system was suggested and preliminary post-closure safety assessment was performed. The DSRSs disposal system was composed of a rock cavern and near surface disposal facilities at the Gyeongju LILW disposal facility. The assessment was conducted using GoldSim program, and probabilistic assessment and sensitivity analysis were implemented to evaluate the uncertainties in the input parameters of natural barriers. Deterministic and probabilistic calculations indicated that the maximum dose was below the regulatory limits ($0.1mSvyr^{-1}$ for the normal scenario, $1mSvyr^{-1}$ for the well scenario). It was concluded that the DSRSs disposal system would maintain environmental safety over a long-time. Moreover, the partition coefficient of Np in host rock, Darcy velocity in host rock, and density of the host rock were the most sensitive parameters in predicting exposure dose in the safety assessment.

Probabilistic Exposure Assessment of Pesticide Residues in Agricultural Products in Gyeonggi-do (경기도내 유통 농산물 중 잔류농약의 확률론적 노출평가 연구)

  • Do, Young-Sook;Kim, Jung-Boem;Kang, Suk-Ho;Kim, Nan-Young;Eom, Mi-Na;Yoon, Mi-Hye
    • The Korean Journal of Pesticide Science
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    • v.17 no.2
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    • pp.117-125
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    • 2013
  • A probabilistic exposure assessment was performed on the monitoring data of pesticides were assessed in agricultural products in Gyeonggi-do from 2006 to 2010. Chlorothalonil, chlorpyrifos, dicofol, endosulfan, EPN, ethoprophos, fenitrothion, methidathion, phenthoate and tebupirimfos were assessed. For this assessment, we used Monte Carlo simulation software and the distribution of concentration and intake were assumed to lognormal distribution by inputting mean and standard deviation. The hazard index (HI, %ADI) of average value and the $95^{th}$ percentile based on a probabilistic method were usually lower than those by a deterministic one. For the whole population, when non-detects data were assigned 0 mg/kg, HI of the average value and the $95^{th}$ percentile showed 0.05~0.70% and 0.11~1.94%, respectively. When nondetects data were assigned 0.005 mg/kg, HI of the average value and the $95^{th}$ percentile were 0.41~4.42% and 0.98~13.81%. For only consumers, when non-detects data were assigned 0 mg/kg, HI of the average value and the $95^{th}$ percentile were 1.24~10.16% and 3.72~33.81%, respectively. When non-detects data were assigned 0.005 mg/kg, HI of the average value and the $95^{th}$ percentile were 3.43~18.26% and 9.45~54.99%, respectively. Methidathion had highest values when both of 0 and 0.005 were assigned to non-detecs data for consumers only. This study showed that agricultural products in Gyeonggi-do were safe because they had less than 100 of HI (%ADI) based on probabilistic exposure assessment.

Estimation of Contamination Level of Listeria monocytogenes in meat and meat products Using Probability Approaches (확률적 접근방법을 이용한 식육에서의 Listeria monocytogenes 오염수준 산출)

  • Park, Gyung-Jin;Kim, Sung-Jo;Shim, Woo-Chang;Chun, Seok-Jo;Choi, Eun-Young;Choi, Weon-Sang;Hong, Chong-Hae
    • Journal of Food Hygiene and Safety
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    • v.18 no.3
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    • pp.107-112
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    • 2003
  • Probabilistic exposure assessment has been recognized as an important tool in microbial risk assessment, because of obtained the desired results to characterize of variability and uncertainty associated with the microbial hazards. In addition, it will be provided much more actuality information than the point-estimate approaches. In this study, we present methodology using mathematical probability distribution in exposure assessment and estimating of contamination level of Listeria monocytogenes in meat and meat products as a case study. The result of estimation contaminatin level was mean ($50^{th}$ percentile) -4.08 Log CFU/g minimum ($5^{th}$ percentile) -4.88 Log CFU/g, maximum ($95^{th}$ percentile) -3.56 Log CFU/g.

Human Exposure Assessment of Pesticide Residues in Cattle by-product Fed the Rice Straw (농약이 잔류된 볏짚조사료을 급여한 소의 부산물 섭취에 따른 인체노출평가)

  • Gil, Geun-Hwan;Paik, Min-Kyoung;Kim, Jin-Bae;Kim, Chan-Sub;Son, Kyung-Ae;Im, Geon-Jae;Ihm, Yang-Bin;Lee, Kyu-Seung
    • The Korean Journal of Pesticide Science
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    • v.17 no.4
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    • pp.249-255
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    • 2013
  • The objective of this study was to investigate the exposure assessment of Korean consumers to edifenphos and tricyclazole in cattle product fed the rice straw, using a probabilistic approach. We used tricyclazole and edifenphos residue data in rice straw reported by National Academy of Agricultural Science (NAAS) for the 1998, 1999, 2001 and 2010 monitoring study and National Agricultural Products Quality Management Service (NAQS) for 2009 monitoring study. The mean exposures of edifenphos and tricyclazole for all of Korean consumers were 0.027% and 0.0006% of ADI and $99%^{th}$ percentile exposures were 0.034% and 0.0007% of ADI respectively. The group of 1~6 years old consumers has the lowest exposure of edifenphos and tricyclazole. The group of 19~29 years old consumers has the highest exposure of edifenphos and tricyclazole.

Exposure and Risk Assessment of Nitrogen Dioxide and Ozone for Sub-population Groups using Monte-Carlo Simulations (Monte-Carlo 모의실험을 통한 부분 인구집단별 이산화질소와 오존의 노출 및 위해성 평가)

  • Park, Jinhyeon;Ryu, Hyeonsu;Yang, So Young;Park, Yunkyung;Heo, Jung;Kim, Eunchae;Choe, Youngtae;Cho, Mansu;Yang, Wonho
    • Journal of Environmental Health Sciences
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    • v.45 no.2
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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 $O_3$.

Exposure and Risk Assessment of Benzene and PM10 for Sub-populations using Monte-Carlo Simulations (Monte-Carlo 모의실험을 통한 부분 인구집단별 벤젠 및 PM10의 노출 및 위해성 평가)

  • Park, Jinhyeon;Yang, So Young;Park, Yunkyung;Ryu, Hyeonsu;Kim, Eunchae;Choe, Youngtae;Heo, Jung;Cho, Mansu;Yang, Wonho
    • Journal of Environmental Health Sciences
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    • v.45 no.3
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    • pp.247-257
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    • 2019
  • Objectives: The Korea Ministry of Environment regulates concentrations of hazardous air pollutants (HAPs) through Atmosphere Environmental Standards to protect public health from HAPs. However, simply determining the exceedance of HAP concentrations has several limitations and more comprehensive assessment is required. In addition, integrated risk assessment is needed considering exposure in all microenvironments, including outdoor as well as indoor environments. The purpose of this study was to assess the differences in risk by sub-population groups according to time-activity patterns and reported concentrations, as well as the lifetime risk for Koreans. Methods: In this study, we calculated time-weighted average exposure concentrations for benzene and $PM_{10}$ among preschool-age children, students, housewifes, workers, and the elderly using residential time and concentrations for indoor (house, school or workplace, other), outdoor, and transport by the meta-analysis method. The risk assessments were conducted by excess cancer risk and disease death risk using 1,000,000 Monte-Carlo simulations for probabilistic analysis. Results: Preschool-age children, students, housewifes, workers, and the elderly spent 91.9, 86.0, 79.8, 82.2, and 77.3% of their day in their house, workplace, or school, respectively. The more than 99% excess cancer risk for benzene exceed 1.0E-06 in all sub-populations and lifetime. The acute disease death risk for $PM_{10}$ for housewifes and workers for lifetime were 3.35E-04 and 3.18E-04, and chronic disease death risks were 2.84E-03 and 2.70E-03, respectively. Conclusions: The risk of benzene and $PM_{10}$ by sub-population group and for the lifetime of housewifes and workers were assessed. Benzene showed risky results for this study. All disease death risks of $PM_{10}$ were higher than 1.0E-04 and showed different risks by sub-population. This study can be used as a basis for lifetime exposure and risk assessment to benzene and $PM_{10}$.

A Deterministic Safety Assessment of a Pyro-processed Waste Repository (A-KRS 처분 시스템 결정론적 안전성 평가)

  • Lee, Youn-Myoung;Jeong, Jongtae;Choi, Jongwon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.3
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    • pp.171-188
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    • 2012
  • A GoldSim template program for a safety assessment of a hybrid-typed repository system, called "A-KRS," in which two kinds of pyro-processed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyro-processing of PWR nuclear spent fuels are disposed of, has been developed. This program is ready both for a deterministic and probabilistic total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios. The A-KRS has been deterministically assessed with 5 various normal and abnormal scenarios associated with nuclide release and transport in and around the repository. Dose exposure rates to the farming exposure group have been evaluated in accordance with all the scenarios and then compared among other.

Human Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) from Road Dust Sediments in Korea (국내 도로 노면 퇴적입자 내 PAHs의 인체 위해성 평가)

  • Lee, Gain;Kim, Hongkyoung;Ji, Seungmin;Jang, Yong-Chul
    • Journal of Environmental Impact Assessment
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    • v.29 no.4
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    • pp.286-297
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    • 2020
  • This research studied human health risk assessment of PAHs (Polycyclic Aromatic Hydrocarbons) in road dust sediments collected from 6 sites in four different cities in Korea. PAHs are well known to be human carcinogens and toxic compounds that are commonly generated from incomplete combustion of fuels and energy products. Such compounds which is absorbed by atmospheric suspended dust can be emitted into air in gaseous form and often deposited on road dust sediments. The PAHs which is deposited on sediment particles can also be re-dispersed by vehicles or winds on the road surface. It can be harmful for humans when exposed via breathing, ingestion and dermal contact. This study examined human health risk assessment of PAHs in deposited road dust sediments. Results showed that the excess cancer risk estimates were above 1.0×10-6 at main traffic roads and resident area in Ulsan city. According to the result of deterministic risk assessment, dermal-contact was the major pathway, while the contribution of the risk from inhalation was less than 1%. The probabilistic risk assessment showed similar levels of cancer risk derived from the deterministic risk assessment. The result of sensitivity analysis reveal that exposure time is the most contributing factor (69%). Since the values of carcinogenic risk assessment were higher than 1.0 × 10-6, further detailed monitoring and refined risk assessment for PAHs may be required to identify more reliable and potential cancer risks for those who live in the study locations in Ulsan city.