• Environmental Analysis Health and Toxicology
• /
• v.20 no.1
• /
• pp.29-37
• /
• 2005

Recently, significant contamination problems by residual chemicals have occasionally been occurred from major rivers and drinking water in Korea. Therefore, the management for use of them and risk assessment should be more strictly performed. In this study, we have analyzed trihalomethanes in treated water samples taken from water plants located in the region of four major rivers (i.e. Han river, Geum river, Youngsan river and Nakdong river) in Korea for eight years (1997～2004). From the data, we could assess the excess cancer risk by calculating the chronic daily intakes (CDI) multiplied by individual oral slope factors, Q₁＊, for the cancer suspected matters such as trihalomethanes, moreover the hazard index which is calculated by dividing the CDI by the acceptable daily reference dose (R/sub f/D) was determined for the risk assessment. As a result, in the case of 95 percentile excess cancer risk, it was shown that the excess cancer risk for dichlorobromomethane in the Nakdong river region is highest among the tested samples as 8.73 x 10/sup -6/. The 95 percentile total hazard index (the sum of individual hazard indices considering R/sub f/D), in addition, was below 1.0 for all samples, and therefore it was assessed that water samples taken from treatment plants of four major rivers are not harmful.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.6
• /
• pp.1602-1613
• /
• 2016

Since Ballast Water Management Convention has been adopted, Ballast Water Management Convention is not effected yet. This convention will only enter into force 12 months after its ratification by 30 states, collectively representing 35% of world merchant shipping tonnnage. Morocco, Indonesia and Ghana have ratified this convention during last 29th IMO Assembly meeting which was held in November 2015. In 2016, Belgium, Fiji, Saint Lucia and Peru have become the latest countries to ratify the convention. As of now, 51 states and 34.87% combined merchant fleets are being calculated. BWM convention will be applied to not only new ships but also, existing ships after it is effected. Thus, existing vessel will be retrofitted a Ballast Water Treatment System according to D-2 Requirement until first IOPP nenewal survey after date of entry into force of the convention. Currently, about 65 BWTSs certified by Administration will be reported to IMO, even type of BWTSs is very various. Thus, a risk of each BWTS can be existed, and this existed risk can be also effected to ship's crew safety and protection of ship's own property. Therefore, we have evaluated a risk assessment for an existing vessel retrofitting an ultra violet type Ballast Water Treatment System which is mostly developed in the world. And we described the procedure of selecting a sample vessel, consequently, bulk carrier is selected because this vessel kind is mostly charged in the world. Especially, DWT 175K size is selected. Risk Assessment is using a HAZID and HAZOP method, evaluation method is referred to IMO Document "Considerated test of the Guidelines for Formal Safety Assessment (FSA) for use in the IMO rule-marking process(MSC/Circ.1203-MEPC/Circ.392)". The Risk Assessment Section is decided to 3 Nodes, Consequently, total risks have evaluated 51 items.

• Environmental Engineering Research
• /
• v.23 no.1
• /
• pp.84-91
• /
• 2018

The present study deals with the management of groundwater resources of an important agriculture track of north-western part of Saudi Arabia. Due to strategic importance of the area efforts have been made to estimate aquifer proneness to attenuate contamination. This includes determining hydrodynamic behavior of the groundwater system. The important parameters of any vulnerability model are geological formations in the region, depth to water levels, soil, rainfall, topography, vadose zone, the drainage network and hydraulic conductivity, land use, hydrochemical data, water discharge, etc. All these parameters have greater control and helps determining response of groundwater system to a possible contaminant threat. A widely used DRASTIC model helps integrate these data layers to estimate vulnerability indices using GIS environment. DRASTIC parameters were assigned appropriate ratings depending upon existing data range and a constant weight factor. Further, land-use pattern map of study area was integrated with vulnerability map to produce pollution risk map. A comparison of DRASTIC model was done with GOD and AVI vulnerability models. Model validation was done with $NO_3$, $SO_4$ and Cl concentrations. These maps help to assess the zones of potential risk of contamination to the groundwater resources.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2003.10a
• /
• pp.170-170
• /
• 2003

An initial study has been conducted with Korea Institute of Geoscience and Mineral resources and National Institute of Environment Research to evaluate the distribution of radon levels and their risk levels of groundwater in Korea. Probability distribution of 616 samples was log-normal one with 1,867pCi/L as arithmetic value, 920pCi/L as median and 40,010pCi/L as maximum during iou. years(1999-2002). In addition, 10% of total samples are in excess of 4,000pCi/L, 20% in excess of 2,700pCi/L, and 30% in excess of 1,700pCi/L, and 15 samples exceeds 10,000pCi/L. Total samples are grouped into 10 areas and 5 rocks unit, and difference of concentrations among areas and rocks are statistically significant(respectively, p<0.0001). The highest area is Daejeon located in ogcheon metamorphic rocks and granitic rocks, and most of all sites with high concentration sites are located in granitic rocks. The lowest area is Jeju located in volcanic rocks. We have estimated excess cancer risks of radon based on these data. To estimate risks, first of all, use patterns of groundwater are categorized with 6 groups: for drinking, household, farming, washing cars, raising stock, and others. We considered risk only for drinking water and household water because radon is rapidly dispersed before it of other use reach human respiratory organs. We select 565 samples for risk analysis, and applied unit risk which is 6.6210-7 per pCi/L to be recommended by NAS committee. Unit risk was derived from considering radon ingestion and radon inhalation from water use. When estimating risk, we analyzed PDF of concentration and represented risk as 50 and 95 percentile values to consider uncertainty with Monte-Carlo simulation. It results in 10-4 level of their excess cancer risk and in 10-2 level in some areas with high concentration of radon. It must be monitor periodically and take adequate actions in these risky sites. We recommend that it needs to take more survey and finally set guideline for radon regulation in groundwater.

• Journal of Korea Water Resources Association
• /
• v.47 no.10
• /
• pp.853-865
• /
• 2014

Hydrologic dam risk analysis depends on complex hydrologic analyses in that probabilistic relationship need to be established to quantify various uncertainties associated modeling process and inputs. However, the systematic approaches to uncertainty analysis for hydrologic risk analysis have not been addressed yet. In this paper, two major innovations are introduced to address this situation. The first is the use of a Hierarchical Bayesian model based regional frequency analysis to better convey uncertainties associated with the parameters of probability density function to the dam risk analysis. The second is the use of Bayesian model coupled HEC-1 rainfall-runoff model to estimate posterior distributions of the model parameters. A reservoir routing analysis with the existing operation rule was performed to convert the inflow scenarios into water surface level scenarios. Performance functions for dam risk model was finally employed to estimate hydrologic dam risk analysis. An application to the Dam in South Korea illustrates how the proposed approach can lead to potentially reliable estimates of dam safety, and an assessment of their sensitivity to the initial water surface level.

• Journal of Korea Water Resources Association
• /
• v.37 no.10
• /
• pp.789-798
• /
• 2004

Conjunctive use of surface and ground water is emerging as an alternative to resolve water shortage problems caused by drought or overpopulation. The region whose water supply depends on a single source has high risk of emergency situations, and may need to consider conjunctive use to overcome its weakness. Conjunctive use also can be a realistic and effective solution when additional or new water resources are to be developed. This paper presents a new methodology for managing surface and ground water resources with the aim of supplying water in a sustainable way. The developed method encompasses procedures to assess site suitability for conjunctive use, to devise water supply scenarios based on drought analysis, and to quantify the amount of water attained. It is believed that the systematic and objective features of the developed method enable it to be a useful supportive tool for water management planning and decision-making.

• The Korean Journal of Pesticide Science
• /
• v.9 no.3
• /
• pp.214-220
• /
• 2005

Initial Risk assessments using physicochemical properties and acute toxicity are conducted to provide information for managers to decide the potential adverse effects and played as a tool for decision-making in development of new substances. In this study, we built initial risk assessment framework and carried out human and ecology initial risk assessment for three different pesticides of captan, glyphosate, and paraquat dichloride to confirm our framework. Two water estimation models of GENEEC (GENeric Estimated Environmental Concentration) and FOCUS (FOrum for the Co-ordination of pesticide models and their USe) were employed for pesticides exposure assessment. Application for paraquat dichloride and glyphosate uses shows very low human and ecology risk. On the other hand, high acute ecological risk was observed from the application for captan. These results showed good agreements with the U.S. EPA RED (Reregistration Eligibility Decision) reports verifying the framework of this study.

• Environmental Engineering Research
• /
• v.13 no.3
• /
• pp.107-111
• /
• 2008

Water quality contamination issues are of critical concern to human health, whilst pesticide release generated from irrigated land should be considered for protecting natural habitats and human health. This paper suggests new method for evaluation and analysis using the GIS technique based on integrated spatial modeling framework. The pesticide use on irrigated land is a subset of the larger spectrum of industrial chemicals used in modern society. The behavior of a pesticide is affected by the natural affinity of the chemical for one of four environmental compartments; solid matter, liquid, gaseous form, and biota. However, the major movements are a physical transport over the ground surface by rainfall-runoff and irrigation-runoff. The irrigated water carries out with the transporting sediments and makes contaminated water by pesticide. This paper focuses on risk impact identification and assessment using GIS technique. Also, generated data on pesticide residues on farmland and surface water through GIS simulation will be reflected to environmental research programs. Finally, this study indicates that GIS application is a beneficial tool for spatial pesticide impact analysis as well as environmental risk assessment.

• Journal of Environmental Impact Assessment
• /
• v.1 no.1
• /
• pp.51-59
• /
• 1992

Environmental Impact Assessment(EIA) is defined as an activity designed to identify and predict the impact on the environment. In the process of an EIA, the quantitative evaluation is generally performed for the air and water quality which have the national environmental quality standards. But the predicted values for the air and water quality are simply compared to the environmental standards. At present, the EIA process of Korea has no consideration for the possible human health risk resulting from the development projects. Environmental Health Impact Assessment(EHIA) is an applied methodology of EIA to estimate the acceptable health risk caused by a specified level of environmental pollutants. Estimating the excessive lifetime risk that is a possibility of dying of a certain disease by environmental contaminants, is useful as an evaluation technique of EHIA. It is recommanded the decision-makers to make efficient use of EHIA not only the development projects but also legislative proposals, policies and programmes in future.

• Journal of Food Hygiene and Safety
• /
• v.35 no.6
• /
• pp.587-601
• /
• 2020

Exposure to hazardous substances occurs through multiple pathways. Aggregated risk assessment, which includes all potential exposure pathways to a single toxicant, is necessary to prevent exposure to harmful substances. We aimed to estimate cadmium and lead exposure through various media, such as food, water, air, smoking, cosmetics, and female hygiene products. This study covered 10,733 subjects from the Seventh Korea National Health and Nutrition Examination Survey(2016, 2017). Dietary exposure was estimated using 24-hour recall data. For water and inhalational exposure, regional variations were considered. Water was classified as tap, bottled, and public water. Inhalational exposure was estimated using the '2014 Time Use Survey' based on daily lifestyle and social status. The frequency and volume of cosmetic usage were randomly approximated by sex and age. Post-menarcheal and premenopausal women were assumed to use feminine hygiene products. Non-carcinogenic aggregated risks were estimated using the Aggregate Risk Index from EPAs and the Total Exposure Hazard Index from Korean government guidelines. For carcinogenic risk assessment, excessive cancer risk was estimated. Ingestion, especially food, was the major route for both cadmium and lead exposure. Smoking was also associated with high cadmium exposure. Exposure to lead from cosmetics was remarkable but not critical. In aggregate risk assessments, median cadmium and lead exposure did not exceed the reference value. Sex, age, smoking status, and income affected exposure levels, unlike to regional variations.