• 한국산업보건학회지
• /
• 제32권3호
• /
• pp.209-220
• /
• 2022

Objectives: This study was performed to suggest how to re-establish criterion for toxic substances under the Chemical Control Act (CCA) in South Korea by comparing the GHS (Globally Harmonized System of Classification and Labeling of Chemicals) score and toxic properties. Methods: Toxic substances were classified into seven groups (Acute toxicity (1A), Chronic toxicity (2C), Environmental hazards (3E), Acute toxicity & chronic toxicity (4AC), Chronic toxicity & environmental hazards (5CE), Acute toxicity & environmental hazards (6AE), and Acute toxicity & chronic toxicity & environmental hazards (7ACE)) according to their toxic properties. The GHS score was calculated to sum up five toxicity indicators (health acute toxicity, health repeated toxicity, carcinogenicity, health other chronic toxicity and environmental hazards). Results: The GHS score of 7ACE was higher by 7 times that of 1A. 1A is the only group which has lower than the total GHS score. The highest score was 47, for sodium chromate (CAS no. 7775-11-3), which belongs to group 7ACE. This is classified as acute toxicity, carcinogenicity, germ cell mutagenicity, reproductive toxicity, and acute and chronic environmental hazard. On the other hand, the lowest score was 2.75, which was assigned to 177 chemicals belonging to group 1A. When the health acute toxicity indicator was omitted from the toxic criterion, toxic substances could be divided into the sub-groups 'human chronic hazards group' (HCG) and 'environmental hazards group' (EG) according to their GHS score and properties. Conclusions: The proposed criterion for toxic substances is to establish sub-groups defined as HCG and EG for separate control and that the 1A group be moved to substances requiring preparation for accidents under the CCA.

• Bulletin of the Korean Chemical Society
• /
• 제31권6호
• /
• pp.1555-1560
• /
• 2010

Quantum dots (QDs) are extensively employed for biomedical research as a fluorescence reporter and their use for various labeling applications will continue to increase as they are preferred over conventional labeling methods for various reasons. However, concerns have been raised over the toxicity of these particles in the biological system. Till date no thorough investigation has been carried out to identify the molecular signatures of QD mediated toxicity. In this study we evaluated the toxicity of CdSe, $Cd_{1-x}Zn_xS$/ZnS and CdSe/ZnS quantum dots having different spectral properties (red, blue, green) using human embryonic kidney fibroblast cells (HEK293). Cell viability assay for both short and long duration exposure show concentration material dependent toxicity, in the order of CdSe > $Cd_{1-x}Zn_xS$/ZnS > CdSe/ZnS. Genome wide changes in the expression of genes upon QD exposure was also analyzed by wholegenome microarray. All the three QDs show increase in the expression of genes related to apoptosis, inflammation and response towards stress and wounding. Further comparison of coated versus uncoated CdSe QD-mediated cell death and molecular changes suggests that ZnS coating could reduce QD mediated cytotoxicity to some extent only.

• Bulletin of the Korean Chemical Society
• /
• 제26권7호
• /
• pp.1079-1082
• /
• 2005

The purpose of this study was to develop a method for increasing the solubility of paclitaxel in water to reduce its toxicity and make the drug more feasible for chemotherapy. A series of highly water soluble paclitaxel polyethylene glycol (PEG) esters were synthesized and evaluated for their anti-tumor activity and toxicity. The solubility of 7-polyethylene glycol paclitaxel carbonate 5 was 840 mg/mL and the acute toxicity ($LD_{50}$) was 286 mg/kg. Because of its reduced toxicity, compound 5 showed a dramatic reduction of tumor volume without any loss of animals in long-term treatment (daily consecutive injections for 15 days).

• Bulletin of the Korean Chemical Society
• /
• 제33권2호
• /
• pp.613-619
• /
• 2012

We applied several machine learning methods for developing QSAR models for prediction of acute toxicity to fathead minnow. The multiple linear regression (MLR) and artificial neural network (ANN) method were applied to predict 96 h $LC_{50}$ (median lethal concentration) of 555 chemical compounds. Molecular descriptors based on 2D chemical structure were calculated by PreADMET program. The recursive partitioning (RP) model was used for grouping of mode of actions as reactive or narcosis, followed by MLR method of chemicals within the same mode of action. The MLR, ANN, and two RP-MLR models possessed correlation coefficients ($R^2$) as 0.553, 0.618, 0.632, and 0.605 on test set, respectively. The consensus model of ANN and two RP-MLR models was used as the best model on training set and showed good predictivity ($R^2$=0.663) on the test set.

• Environmental Analysis Health and Toxicology
• /
• 제20권2호
• /
• pp.109-121
• /
• 2005

A chemical ranking and scoring (CRS-Korea) system was developed and proposed to use as the first step to prioritize the toxic chemicals for the purpose of monitoring and detailed risk assessment that might follow as necessary. The CRS-Korea system takes a basic concept of risk assessment (both human health risk and ecological risk) in that risk score is determined by the product of toxicity score and exposure score. Included in the toxicity category are acute toxicity, chronic/sub -chronic toxicity, carcinogenicity, and other toxicity. The exposure category consists of quantity released to the environment, bioconcentration, and persistence. A consistent scheme and a comprehensive chemical data base are offered in the CRS-Korea system to calculate a score for the each component in the two categories by using specific physicochemical, fate, and toxic properties and the quantity of the chemical used. The toxicity score is obtained by adding up all the individual scores for the components in the toxicity category. The exposure score is determined by multiplication of the score of the quantity released with the sum of persistent score and bioconcentration score. Equal weight is given to the toxicity score and the exposure score. As the CRS-Korea system was applied to identify 50 national priority chemicals, it was found that significant data gap exists on toxicity and fate properties and that the uncertainty associated with estimating the quantify released to the environment is notably high. The proposed CRS system is only a screening tool in the first step toward the priority setting and should be used with expert judgement and other considerations necessary.

• Environmental Analysis Health and Toxicology
• /
• 제24권2호
• /
• pp.95-105
• /
• 2009

Chemical Ranking and Scoring (CRS) system is a useful tool to screen priority chemicals of large body of substances. The relative ranking of chemicals based on CRS system has served as a decision-making support tools. Exposure potential and toxicity are significant parameters in CRS system, and there are differences in evaluating those parameters in each CRS system. In this study, the parameters of exposure potential, human toxicity, and ecotoxicity were extensively compared. In addition the scoring methods in each parameter were analyzed. The CRS systems considered in this study include the CHEMS-1 (Chemical Hazard Evaluation for Management Strategies), SCRAM (Scoring and Ranking Assessment Model), EURAM (European Union Risk Ranking Method), ARET (Accelerated Reduction/Elimination of Toxics), and CRS-Korea. An comparative analysis of the several CRS systems is presented based on their assessment parameters and scoring methods.

• 한국산업보건학회지
• /
• 제29권2호
• /
• pp.141-158
• /
• 2019

Objectives: An adverse outcome pathway is a biological pathway that disturbs homeostasis and causes toxicity. It is a conceptual framework for organizing existing biological knowledge and consists of the molecular initiating event, key event, and adverse output. The AOP concept provides intuitive risk identification that can be helpful in evaluating the carcinogenicity of chemicals and in the prevention of cancer through the assessment of chemical carcinogenicity predictions. Methods: We reviewed various papers and books related to the application of AOPs for the prevention of occupational cancer. We mainly used the internet to search for the necessary research data and information, such as via Google scholar(http://scholar.google.com), ScienceDirect(www.sciencedirect.com), Scopus(www.scopus. com), NDSL(http: //www.ndsl.kr/index.do) and PubMed(http://www.ncbi.nlm.nih.gov/pubmed). The key terms searched were "adverse outcome pathway," "toxicology," "risk assessment," "human exposure," "worker," "nanoparticle," "applications," and "occupational safety and health," among others. Results: Since it focused on the current state of AOP for the prediction of toxicity from chemical exposure at work and prospects for industrial health in the context of the AOP concept, respiratory and nanomaterial hazard assessments. AOP provides an intuitive understanding of the toxicity of chemicals as a conceptual means, and it works toward accurately predicting chemical toxicity. The AOP technique has emerged as a future-oriented alternative to the existing paradigm of chemical hazard and risk assessment. AOP can be applied to the assessment of chemical carcinogenicity along with efforts to understand the effects of chronic toxic chemicals in workplaces. Based on these predictive tools, it could be possible to bring about a breakthrough in the prevention of occupational and environmental cancer. Conclusions: The AOP tool has emerged as a future-oriented alternative to the existing paradigm of chemical hazard and risk assessment and has been widely used in the field of chemical risk assessment and the evaluation of carcinogenicity at work. It will be a useful tool for prediction, and it is possible that it can help bring about a breakthrough in the prevention of occupational and environmental cancer.

• Environmental Analysis Health and Toxicology
• /
• 제21권2호
• /
• pp.197-208
• /
• 2006

The hazards of chemicals can be classified using classification criteria that are based on physical, chemical and ecotoxicological endpoints. These criteria may be developed be iteratively, based on scientific or regulatory processes. A number of national and international schemes have been developed over the past 50 years, and some, such as the UN Dangerous Goods system or the EC system for hazardous substances, are in widespread use. However, the unnecessarily complicated multiplicity of existing hazard classifications created much unnecessary confusion at the user level, and a recommendation was made at the 1992 Rio Earth summit to develop a globally harmonized chemical hazard classification and compatible labelling system, including material safety data sheets and easily understandable symbols, that could be used for manufacture, transport, use and disposal of chemical substances. This became the globally harmonized system for the Classification and Labelling of Chemicals (GHS). The developmental phase of the GHS is largely complete. Consistent criteria for categorizing chemicals according to their toxic, physical, chemical and ecological hazards are now available. Consistent hazard communication tools such as labelling and material safety data sheets are also close to finalizations. The next phase is implementation of the GHS. The Intergovernmental Forum for Chemical Safety recommends that all countries implement the GHS as soon as possible with a view to have the system fully operational by 2008. When the GHS is in place, the world will finally have one system for classification of chemical hazards.

• Environmental Analysis Health and Toxicology
• /
• 제9권3_4호
• /
• pp.91-101
• /
• 1994

In order to evaluate the ecotoxicological harzardousness of synthetic surfactants on Han river, Jung-ryang and Jin-Wi stream, we used the Ecotoxicological Risk Quotient (ERQ). The chemical harzardousness is evaluated by the balance of the toxicity and concentration in the environment.. Then, ERQ is defined as follows; ERQ = - log ( Concentration in the environment / Effective concentration in the test ) ERQ of chemical is a logtrighmic value of ratio of a chemical concentration and the toxicity in the laboratory. In case of small ERQ, tie chemical harzardousness is high. If ERQ equals O, the same biological effect as in the laboratory test will be observed in the enviromment by the chemicals. ERQ values of the chemicals were calculated using the maximum concentration in water environment which were cited from the annual report by our ministry of environment, and EC$_{50}$ of Daphnia magna (water flea; acute immobilization test) LC$_{50}$ of Oryzias latipes (fish; acue toxicity test) and EC$_{50}$ of chlorella vulgaris (alga; growth inhibition test), which were taken from the annual report of "Chemical in environment" by Japan EA. Liner alkylbenzene sulfonate (determined to MBAS) showed the high average values with more than 2.0 to three species in Han river and Jin-wi stream, and these results mean to be favorable to environmental safety. The areas of Jung-ryang stream were polluted, as the average values of ERQ were less than 2.0 with equal to three species, and attention should be paid. Therefore, they must be inspected again because their concentration in the environment may have changed during that period. The chemical harzardousness can be numerated with ERQ, and it can be a help to find the chemicals that should be kept under observation and to see whether the chemical pollution is improved or worsened. The determination of the chemical concentration in the environment and toxicity are essential for the effective use of ERQ.se of ERQ.

• Ocean Science Journal
• /
• 제40권2호
• /
• pp.91-100
• /
• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.