• Advances in environmental research
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• v.2 no.2
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• pp.119-129
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• 2013

The study examined the effect of urbanization on the water quality of Nwaorie and Otamiri Rivers in Owerri metropolis, Imo State, South-East Nigeria. Water samples were collected from Nwaorie and Otamiri Rivers from four sampling stations up and down stream. Water parameters analyzed using standard procedures were: color, turbidity, temperature, pH, total hardness, total solids, metals (Iron and magnesium), anions (nitrate and ammonia) and Fecal coliform. Results showed increased levels of coloration, iron, ammonia, turbidity and fecal coliform which exceeded the World Health Organization (WHO) permissible limits for drinking water. Increase in these parameters indicated influx of industrial effluent from the nearby industries and indiscriminate disposal of wastes at the bank of the rivers. Application of ANOVA showed various degree of variation in pollutants levels between the two rivers and at different sampling points. River Nwaorie was observed to be more impacted than River Otamiri. High values of iron observed from the study could be deleterious to human health if the river water is consumed without treatment. The study, therefore, recommended proper waste management and disposal as well as effluent treatments in Owerri municipal against pollution of surface water.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.1-10
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• 2001

Some phenomena in which insects can demonstrate environmental changes by xenobiotics are easily and simply evaluated. On this regard, general guidelines for environmental studies using insects as biomarkers which determine the effects of such changes are suggested. Insects include three-quaters of all living animal species. This diversity comprises many closely related species which may respond sole to environmental changes by xenobiotics. Insects have been used for assessing adverse effects of environmental changes by xenobiotics, especially pesticides. Collembolan species are widely used as physiological and behavioral biomarkers for the assessment of adverse effects caused by pesticides on soil environment. This review aims to evaluate tile possible use of Korean Collembolan species based upon their response to environmental changes in Korean soil mainly caused by pesticides for crop protection.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.75-82
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• 1994

Bioconcentration Factor (BCF) is known as important criteria for ecotoxicology on hazardous chemicals. But there is no standard method for determining BCF and reported BCFs were slightly different in accordance with authors. This study was performed with aims to determine BCFs on BPMC and Carbaryl. Carassius auratus(goldfish) be chosen as test organism and test period were 3-day, 5-day and 10-day. Extract solvents were n-hexane and acetonitrile. GC-ECD was used to detecting carbamates. The obtained results were as follows: 1. It was possible to determine short term BCF$_s$ of Carbaryl or BPMC through relatively simple procedure. 2. BCF$_3$ of Carbaryl in concentration of 1, 2, 5, 10 ppm were 0.34 $\pm$ 0.06, 0.18 $\pm$ 0.02, 0.10 $\pm$ 0.01, 0.06 $\pm$ 0.01 respectively. BCF$_5$ of Carbaryl were 0.34 $\pm$ 0.05, 0.18 $\pm$ 0.02, 0.13 $\pm$ 0.01 and 0.07 $\pm$ 0.01, BCF$_{10}3$ of Carbaryl were 0.45 $\pm$ 0.05, 0.27 $\pm$ 0.02, 0.16 $\pm$ 0.02 and 0.09 $\pm$ 0.01. BCF$_3$ of BPMC in concentration of 1, 2, 5 ppm were 4.66 $\pm$ 0.17, 2.64 $\pm$ 0.49, 1.88 $\pm$ 0.24 respectively. BCF$_5$ of BPMC were 4.09 $\pm$ 0.50, 2.42 $\pm$ 0.37 and 1.83 $\pm$ 0.15. 3. BCF$_s$ of BPMC were decreased as increasing concentration. However, BPMC concentration in fish were increased in contrast to BCF. But more concentrated BPMC was found in fish 3-day test than found concentration in fish 5-day test. 4. Same trend appeared in Carbaryl. BCF$_s$ of Carbaryl were decreased as increasing concentration and prolonging test period. But found Carbaryl concentration in fish were increased. 5. BCF$_s$ of BPMC were higher than that of Carbaryl by 10 times, in spite of the physicochemical properties of the two carbamates were similar to each other. Further study is recommended to find out the reason of the difference.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.1006-1013
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• 2014

Wastewater organic compounds, that is, nonylphenolic compounds (NPs) and fecal sterols, were measured in surface sediments from Busan Suyeong Estuary, where two wastewater treatment plants (WWTPs) are located, to assess contamination from municipal effluents. The NPs analyzed were nonylphenol, and nonylphenol mono- and di-ethoxylates, all synthetic endocrine disruptors. The fecal sterols analyzed were coprostanol (COP), cholestanol, and epicoprostanol. Concentrations of NPs in the sediments ranged from 146 to 3,723 ng/g, and those of COP ranged from 366 to 13,018 ng/g. Their detection in all of the sediments analyzed indicates widespread pollution by municipal effluents. The highest concentrations of NPs and COP were detected at stations close to outfalls of WWTPs. Their levels in sediments are categorized in the higher range of those previously reported in Korean coastal areas. Moreover, in comparison with screening values of NPs in the Netherlands, Norway, and Canada, more than 50% of the sampling stations exceeded the guidelines. This indicates that the estuary may be adversely influenced by municipal effluents.

• Environmental Analysis Health and Toxicology
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• v.26
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• pp.10.1-10.7
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• 2011

Objects: Chironomus riparius, a non-biting midge (Chironomidae, Diptera), is extensively used as a model organism in aquatic ecotoxicological studies, and considering the potential of C. riparius larvae as a bio-monitoring species, little is known about its genome sequences. This study reports the results of an Expressed Sequence Tags (ESTs) sequencing project conducted on C. riparius larvae using 454 pyrosequencing. Method: To gain a better understanding of C. riparius transcriptome, we generated ESTs database of C.ripairus using pyrosequencing method. Results: Sequencing runs, using normalized cDNA collections from fourth instar larvae, yielded 20,020 expressed sequence tags, which were assembled into 8,565 contigs and 11,455 singletons. Sequence analysis was performed by BlastX search against the National Center for Biotechnology Information (NCBI) nucleotide (nr) and uniprot protein database. Based on the gene ontology classifications, 24% (E-value${\leq}1^{-5}$) of the sequences had known gene functions, 24% had unknown functions and 52% of sequences did not match any known sequences in the existing database. Sequence comparison revealed 81% of the genes have homologous genes among other insects belonging to the order Diptera providing tools for comparative genome analyses. Targeted searches using these annotations identified genes associated with essential metabolic pathways, signaling pathways, detoxification of toxic metabolites and stress response genes of ecotoxicological interest. Conclusions: The results obtained from this study would eventually make ecotoxicogenomics possible in a truly environmentally relevant species, such as, C. riparius.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.191-199
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• 2012

Objectives: The study aim was to evaluate the application of a chemical exposure assessment tool for the Korean workplace. The Ministry of Employment and Labor in Korea (KMOEL) introduced the need for workplace risk assessments in 2011, requiring the Korean chemical industry to consider both domestic and international chemical regulation policies (e.g., estimations of exposure scenarios). Exposure scenarios are required in the European Union as part of material safety data sheets (MSDS) under the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) system. Methods: Although many programs for the estimation of exposure have been developed worldwide, to date there is no standard for the Korean workplace. To develop programs suitable for the Korean workplace, we examined the applicability of the European Center for Ecotoxicology and Toxicology of Chemicals target risk assessment (ECETOC TRA), which is recommended by the European Chemical Agency (ECHA). Results: To investigate the applicability of the ECETOC TRA to Korean industry, this study simulated 15 industrial processes. The predicted respiratory exposures for four processes using origin input parameters were underestimated compared to the measured respiratory exposure. Using calibrated input parameters, results for two processes were underestimated compared to the measured respiratory exposure. This result suggests that the use of calibrated input parameters reduces the differences between predicted and measured respiratory exposure. Conclusions: we developed applicable exposure estimating method by modifying the ECETOC TRA program; one suggested the development of exposure estimating program that explains Korea domestic workplace exposure scenario.This study will support the introduction of exposure scenario in MSDS system and protect health of worker from hazardous chemical.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.3
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• pp.358-367
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• 2019

Objectives: This study aimed to review model algorithms and input parameters applied to some exposure models and to compare the simulated estimates using an exposure scenario from each model. Methods: A total of five exposure models which can estimate inhalation exposure were selected; the Korea Ministry of Environment(KMOE) exposure model, European Centre for Ecotoxicology and Toxicology of Chemicals Targeted Risk Assessment(ECETOC TRA), SprayExpo, and ConsExpo model. Algorithms and input parameters for exposure estimation were reviewed and the exposure scenario was used for comparing the modeled estimates. Results: Algorithms in each model commonly consist of the function combining physicochemical properties, use characteristics, user exposure factors, and environmental factors. The outputs including air concentration ($mg/m^3$) and inhaled dose(mg/kg/day) are estimated applying input parameters with the common factors to the algorithm. In particular, the input parameters needed to estimate are complicated among the models and models need more individual input parameters in addition to common factors. In case of CEM, it can be obtained more detailed exposure estimates separating user's breathing zone(near-field) and those at influencing zone(far-field) by two-box model. The modeled exposure estimates using the exposure scenario were similar between the models; they were ranged from 0.82 to $1.38mg/m^3$ for concentration and from 0.015 to 0.180 mg/kg/day for inhaled dose, respectively. Conclusions: Modeling technique can be used for a useful tool in the process of exposure assessment if the exposure data are scarce, but it is necessary to consider proper input parameters and exposure scenario which can affect the real exposure conditions.

• Entomological Research
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• v.48 no.6
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• pp.533-539
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• 2018

The RNA interference (RNAi) has been considered as an important genetic tool and applied to develop a new living modified (LM) crop trait which is an improvement of nutrient quality or pest management. The RNAi of DvSnf7 has been used for resistance to LM maize and the Western Corn Rootworm which is a major agricultural pest for the US Corn Belt. Most of the environmental risk assessments (ERA) of double strand RNA (dsRNA) have been performed using in vitro transcript products, and not in vivo expressed product. A large amount of dsRNA was required for the acute toxicity assay of water fleas. Therefore development of massive dsRNA purification techniques is critical. Daphnia, a freshwater microcrustacean, is a model organism for studying cellular and molecular mechanism involved in life history traits and ecotoxicology. In this study, we established the massive dsRNA purification method using Escherichia coli and implemented acute toxicity assays to Daphnia magna. As a result, the present RNase A and DNase I, dsRNA was efficiently purified without any special techniques or equipment. Even though purified dsRNA existed during the acute toxicity test, lethality or abnormal behavior were not observed in D. magna. These results indicated that GFP and DvSnf7 dsRNA were not significantly affected to D. magna due to their lack of sequence matching in its genome. The purification method of dsRNA and the acute toxicity assay of water fleas using purified dsRNA would be suitable for the toxicological studies of LMOs to aquatic non-target organisms.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.138-145
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• 2024

Background: Appropriateness issues have emerged regarding the non-application of hazardous substance safety standards for items classified as 'other textile products'. Objectives: Testing for formaldehyde (HCHO) and risk assessment were conducted on 'other textiles products' to provide reference data for promoting product safety policies. Methods: Testing was conducted on five items (102 products) classified as 'other textile products' according to relevant standards (textile products safety standards), and the risk of each product was assessed using the evaluation methodologies of the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) and European Chemical Agency (ECHA). Results: Out of the 102 products tested, HCHO was detected above the quantification limit in five. Based on these results, the screening risk assessment indicated that three products exceeded the criteria. Upon reassessing the emission and transfer rates of products exceeding the criteria, it was confirmed that there were no instances of exceeding the criteria. Conclusions: Risk assessment results can be used as supporting data for non-application of hazardous substance standards. However, it is deemed necessary to transition towards a management approach based on risks in order to addressing emerging trends such as convergence/new products.

• Korean Journal of Ecology and Environment
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• v.43 no.3
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• pp.356-368
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• 2010

In this study, we applied approach of integrative star-plot area (SPA), chemical water quality and habitat conditions (QHEI) to diagnoze ecological conditions at the eight sampling sites of Sapkyo Stream. These outcomes were compared with biological health based on the Index of Biological Integrity (IBI) using fish assemblage. And then, we evaluated the integrative ecological health condition using the star-plot method. This approach based on the sum of all the star-plot areas over these water and habitat characteristics. It was developed to reflect an integrative assessment of the ecological health in the stream. The biological health, based on the model values of IBI indicating "fair-poor" condition according to the criteria. Physical habitat health, based on the QHEI, averaged 123 indicating a "good-fair" condition. Also, chemical health, based on simply BOD values indicating "poor grade" according to the criteria of the Ministry of Environment Korea (MEK). The SPA indicating that 50% of the all was impaired condition and the most sampling sites were downstream sites influenced by the point and non-point sources. Overall our results suggest that the ecological health impact was a combined effect of eutrophication and habitat degradations in the stream. The approach of SPA can be used as a tool to evaluate the integrative health of stream environment and to identify possible causes of observed effects.