• Journal of Environmental Health Sciences
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• v.48 no.3
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• pp.159-166
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• 2022

Background: A quantitative structure-activity relationship (QSAR) model was adopted in the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH, EU) regulations as well as the Act on Registration, Evaluation, etc. of Chemicals (AREC, Republic of Korea). It has been previously used in the registration of chemicals. Objectives: In this study, we investigated the correlation between the predicted data provided by three prediction programs using a QSAR model and actual experimental results (acute fish, daphnia magna toxicity). Through this approach, we aimed to effectively conjecture on the performance and determine the most applicable programs when designating toxic substances through the AREC. Methods: Chemicals that had been registered and evaluated in the Toxic Chemicals Control Act (TCCA, Republic of Korea) were selected for this study. Two prediction programs developed and operated by the U.S. EPA - the Ecological Structure-Activity Relationship (ECOSAR) and Toxicity Estimation Software Tool (T.E.S.T.) models - were utilized along with the TOPKAT (Toxicity Prediction by Komputer Assisted Technology) commercial program. The applicability of these three programs was evaluated according to three parameters: accuracy, sensitivity, and specificity. Results: The prediction analysis on fish and daphnia magna in the three programs showed that the TOPKAT program had better sensitivity than the others. Conclusions: Although the predictive performance of the TOPKAT program when using a single predictive program was found to perform well in toxic substance designation, using a single program involves many restrictions. It is necessary to validate the reliability of predictions by utilizing multiple methods when applying the prediction program to the regulation of chemicals.

• The Research Journal of the Costume Culture
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• v.7 no.3
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• pp.142-153
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• 1999

The objective of this study was to analysis the pesticide chemical-using of farm workers and working clothes for diminishing the possible damage by their improper chemicals usages. For the data Questionairs were collected 340 from the farm families of the 3 different districts in Yeoju, Kyonggido, and also inquired of the persons in charge of the chemicals and of the laundry in each family. Among the replies, 233 was classified as useful, and analyzed the frequency, the percentage and correlation. The results were as follows : 1. 64.3% of the farmers were using the chemicals for 5∼20 years, of whom 33.6% experienced stopping of chemicals-using for health. 2. The applicators experienced poisoning symptoms such as habitual fatigue, hadache, dizziness, chest discomfort, eye irritation, skin irritation, blurred vision, vomiting, nausea etc. after chemical work. 3. 74.7% answered they did not obtained educational information for the care of chemicals contaminated clothes. 69.1% said they need to obtain educational information about safety awareness of agricultural chemicals.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.105-113
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• 2014

Objectives: It is necessary to apply quantitative structure activity relationship (QSAR) for the various chemicals with insufficient toxicity data that are used in the workplace, based on the precautionary principle. This study aims to find application plan of QSAR software tool for predicting health hazards such as genetic toxicity, and carcinogenicity for some chemicals used in the electronics industries. Methods: Toxicity prediction of 21 chemicals such as 5-aminotetrazole, ethyl lactate, digallium trioxide, etc. used in electronics industries was assessed by Toxicity Prediction by Komputer Assisted Technology (TOPKAT). In order to identify the suitability and reliability of carcinogenicity prediction, 25 chemicals such as 4-aminobiphenyl, ethylene oxide, etc. which are classified as Group 1 carcinogens by the International Agency for Research on Cancer (IARC) were selected. Results: Among 21 chemicals, we obtained prediction results for 5 carcinogens, 8 non-carcinogens and 8 unpredictability chemicals. On the other hand, the carcinogenic potential of 5 carcinogens was found to be low by relevant research testing data and Oncologic TM tool. Seven of the 25 carcinogens (IARC Group 1) were wrongly predicted as non-carcinogens (false negative rate: 36.8%). We confirmed that the prediction error could be improved by combining genetic toxicity information such as mutagenicity. Conclusions: Some compounds, including inorganic chemicals and polymers, were still limited for applying toxicity prediction program. Carcinogenicity prediction may be further improved by conducting cross-validation of various toxicity prediction programs, or application of the theoretical molecular descriptors.

• Environmental Analysis Health and Toxicology
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• v.30 no.sup
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• pp.1.1-1.5
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• 2015

Objectives Despite the great contribution made by chemical substances to the development of modern civilization, their indiscriminate use has caused various kinds of damage to the global environment and human beings. Accordingly, the major developed countries and international society have tried to ensure the safe use of chemicals and a reduction in the use of hazardous chemicals through the establishment of the United Nations Environment Programme and various international agreements. In this reason, we tried to introduce about Green Chemistry progress at the present in worldwide and Korea. Methods We checked and analyzed relative journals, reports using keyword as like Green Chemistry, alternative chemicals, eco-friendly etc. and major country's government homepage search. Results Green Chemistry theory, which argues for the reduction or removal of harmfulness in chemicals throughout their entire life-cycle, has been spreading, and major developed countries, such as the US and Denmark, have developed and operate programs to provide reliable chemical information to help replace hazardous chemicals. Korea has also been conducting studies as like eco-innovation project. Through this project the "Alternative Chemical Search program," has been developed, distributed, and operated since 2011 to provide reliable information to small and medium-sized businesses that have difficulties collecting information to ensure conformity to international regulations. The program provides information that includes the regulations of major countries and Korea, information on 340 alternative chemicals, 70 application cases, and 1:1 consulting. Conclusions The Alternative Chemical Search program is expected to contribute to the establishment of response systems for regulation of Korean small and medium-sized businesses, and it also will be used to provide basic data for Korean hazardous chemical regulation, together with the Act on the Registration and Evaluation, etc. of Chemical Substances and the Chemical Control act, making it possible to establish an infrastructure for Green Chemistry in Korea and to increase national competitiveness.

• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.153-159
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• 2018

Objectives: This study was carried out to determine $LD_{50}$ of benzo[a]pyrene to decide the possibility to designate them as toxic substance on the Act on the Registration and Evaluation, etc. of Chemical Substances, and to suggest that they should be managed in what level on the Chemical Control Act. Methods: Based on the result of a preliminary study, 300 mg/kg was set as the middle dose. A highest dose of 2,000 mg/kg and a lowest dose of 50 mg/kg were selected based on the OECD TG 423. Benzo[a]pyrene was orally administered once to female and male SD rats at dose levels of 50, 300, 2,000 mg/kg (body weight). All animals were monitored daily for clinical signs and mortality over 14 days. Also testicular spermatid count, motility and etc. were examined as well. Results: Under the condition of this experiment, $LD_{50}$ of benzo[a]pyrene was assumed to be >2,000 mg/kg. In the lesion according to autopsy, there were no specific symptoms in the control and experimental groups. At 2,000 mg/kg, a decrease in the sperm motility was observed. Benzo[a]pyrene should be designated to be toxic substance as the material assumed to be reproduction-toxicity on the Act on the Registration and Evaluation, etc. of Chemicals. Therefore we should abide by legal procedures determined by Chemicals Control Act in treating it. Conclusion: Considering the significant result that sperm motility in the experimental group was inferior to that in the reference group, we suggest that benzo[a]pyrene be designated as a toxic substance.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.58-71
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• 2015

Objectives: The aims of this study were to investigate the classification system of chemical substances in the Occupational Safety and Health Act(OSHA) and Chemical Substances Control Act(CSCA) and to compare several health indices (i.e., Time Weighted Average (TWA), Lethal Dose ($LD_{50}$), and Lethal Concentration ($LC_{50}$) of chemical substances by categories in each law. Methods: The chemicals regulated by each law were classified by the specific categories provided in the respective law; seven categories for OSHA (chemicals with OELs, chemicals prohibited from manufacturing, etc., chemicals requiring approval, chemicals kept below permissible limits, chemicals requiring workplace monitoring, chemicals requiring special management, and chemicals requiring special heath diagnosis) and five categories from the CSCA(poisonous substances, permitted substances, restricted substances, prohibited substances, and substances requiring preparation for accidents). Information on physicochemical properties, health indices including CMR characteristics, $LD_{50}$ and $LD_{50}$ were searched from the homepages of the Korean Occupational and Safety Agency and the National Institute of Environmental Research, etc. Statistical analysis was conducted for comparison between TWA and health index for each category. Results: The number of chemicals based on CAS numbers was different from the numbers of series of chemicals listed in each law because of repeat listings due to different names (e.g., glycol monoethylether vs. 2-ethoxy ethanol) and grouping of different chemicals under the same serial number(i.e., five different benzidine-related chemicals were categorized under one serial number(06-4-13) as prohibited substances under the CSCA). A total of 722 chemicals and 995 chemicals were listed at the OSHA and its sub-regulations and CSCA and its sub-regulations, respectively. Among these, 36.8% based on OSHA chemicals and 26.7% based on CSCA chemicals were regulated simultaneously through both laws. The correlation coefficients between TWA and $LC_{50}$ and between TWA and $LD_{50}$, were 0.641 and 0.506, respectively. The geometric mean values of TWA calculated by each category in both laws have no tendency according to category. The patterns of cumulative graph for TWA, $LD_{50}$, $LC_{50}$ were similar to the chemicals regulated by OHSA and CCSA, but their median values were lower for CCSA regulated chemicals than OSHA regulated chemicals. The GM of carcinogenic chemicals under the OSHA was significantly lower than non-CMR chemicals($2.21mg/m^3$ vs $5.69mg/m^3$, p=0.006), while there was no significant difference in CSCA chemicals($0.85mg/m^3$ vs $1.04mg/m^3$, p=0.448). $LC_{50}$ showed no significant difference between carcinogens, mutagens, reproductive toxic chemicals and non-CMR chemicals in both laws' regulated chemicals, while there was a difference between carcinogens and non-CMR chemicals in $LD_{50}$ of the CSCA. Conclusions: This study found that there was no specific tendency or significant difference in health indicessuch TWA, $LD_{50}$ and $LC_{50}$ in subcategories of chemicals as classified by the Ministry of Labor and Employment and the Ministry of Environment. Considering the background and the purpose of each law, collaboration for harmonization in chemical categorizing and regulation is necessary.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.112-112
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• 2003

Air pollution is made up by complex mixture exhausted from cars, industries and incinerators etc. Those pollutants come from everywhere without border and contain phototoxic and photogenotoxic chemicals including PAHs exhausted in the air. We have published that the chemicals which show phototoxicity and photogenotoxicity are closely related in mechanistic and the PAHs react as a strong photocatalyzer by radical productions under UV exposure.(omitted)

• Journal of Plant Biotechnology
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• v.4 no.4
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• pp.171-178
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• 2002

Chlorophyll (Chl) fluorescence imaging was used to investigate the effectiveness of in vivo incorporation methods for two chemicals, 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) and methyl viologen (MV) in rice, a monocot, and cucumber, a dicot, leaves. four different methods (vacuum infiltration, floating, transpiration-aided incorporation through petiole and spraying) were compared, and $F_i$ and $F_v$/$F_m$ were chosen for the imaging of the DCMU- and MV-treated leaves, respectively. The effects of the chemicals in plants were generally heterogeneous over the whole leaf area. Moreover, the effectiveness of the treatment of a chemical in plant leaves was dependent on chemical species, plant species, concentration of the chemical, the treatment method, the duration of the treatment, the existence of light and detergent, etc. In conclusion, we suggest that to achieve the proposed effects of chemicals in plants for an actual experiment, these factors must be considered before the chemical treatment, and the best method for the treatment of the chemicals tested was floating and vacuum infiltration in the dicot and the monocot leaves, respectively, as drawn from Chl fluorescence imaging analysis.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.317-320
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• 1997

In the water purification plant, chemicals are injected for quick purification of raw water. It is clear that the amount of chemicals intrinsically depends on the water quality such as turbidity, temperature, pH and alkalinity etc. However, the process of chemical reaction to improve water quality by the chemicals is not yet fully clarified nor quantified. The feedback signal in the process of coagulant dosage, which should be measured (through the sensor of the plant) to compute the appropriate amount of chemicals, is also not available. Most traditional methods focus on judging the conditions of purifying reaction and determine the amounts of chemicals through manual operation of field experts or jar-test results. This paper presents the method of deriving the optimum dosing rate of coagulant, PAC(Polymerized Aluminium Chloride) for coagulant dosing process in water purification system. A neural network model is developed for coagulant dosing and purifying process. The optimum coagulant dosing rate can be derived the neural network model. Conventionally, four input variables (turbidity, temperature, pH, alkalinity of raw water) are known to be related to the process, while considering the relationships to the reaction of coagulation and flocculation. Also, the turbidity in flocculator is regarded as a new input variable. And the genetic algorithm is utilized to identify the neural network structure. The ability of the proposed scheme validated through the field test is proved to be of considerable practical value.

• Journal of Environmental Impact Assessment
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• v.14 no.2
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• pp.83-96
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• 2005

Brominated flame retardants have the market share of 40%, comparing others because of their low cost and highly effective retardation against the flame. However, their toxic effects in human and properties of the accumulation in the environments have been issued among the international organization such as EU, OECD and etc. It, therefore, was surveyed the classification, toxic effects, and the usage of Brominated flame retardants, the trends for their managements in the world and Korea, and their contaminated levels in Korean Peninsula. In addition, the management directions for them were proposed. Penta, octa, and deca-BDE among brominated retardants will seem to be prohibited by the regulation as a flame retardants for plastics in Europe because of their toxic effects. Although Penta and Octa BDEs was used marginally in Korea, deca-BDE was 27% of brominated flame retardants (49,050 ton) which had been used in 2002. However, risk assessment for brominated retardants might not launched in Korea, yet. These reports demonstrate that toxic brominated retardants such as PBDEs will be assessed for their usage and the level of contamination in the environment in the area of the point sources like the industrial areas, incinerators and etc. However, the law to regulate the hazardous chemicals seems not to be dictated the monitoring of their contamination in the environment. We, therefore, suggest how to evaluate and to monitor the toxic contaminants with EIA (Environmental Impact Assessment) and LCA (Life Cycle Assessment) system. Further, to establish the management system of BFRs (such as the monitering of contamination levels in environments, life cycle assessment, and risk assessment for the toxic chemicals), It can be recommended the law to deal with the method analyzing chemicals will be established, which contains QA/QC (Quality Assurance and Quality Control) to evaluate the analytic capability of the companies to prepare EIS (Environment Impact Statement) or other institutes for analyzing chemicals.