• Journal of Wetlands Research
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• v.17 no.4
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• pp.407-413
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• 2015

As the number of applications containing nanomaterials increase, aquatic ecosystem exposure to nanoparticles (NPs) is unavoidable. In this study, we carried out toxicity assessment to Au-nanoparticles(NPs) of Rana dybowskii eggs and tadpoles. Toxicity was recorded hatching rate, body condition(Snout-tail length, STL), and behavioral sensitivity. Behavioral sensitivity was analyzed to anti-predator behavior using Ethovision XT 9. Au-NPs did not show any toxicity of hatching rate and STL. But, Tadpoles exposed to Au-NPs decrease behavioral sensitivity of stimuli. This study has value of environmental toxicity evaluation because these results show the new way of toxicity assessment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.73-81
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• 2012

Object: The aim of this study is to suggest a list of priority chemicals for the Hazard & Risk Evaluation of Chemicals (HREC) controlled by the Industrial Safety and Health Act (ISHA). Method: Screening assessment was done for 642 chemicals whose exposure threshold limit values were set by the Ministry of Employment and Labor (MOEL). Hazard data were collected from Korea Occupational Safety & Health Agency (KOSHA) and/or other toxicity database. Exposure data were obtained from KOSHA internal database. The hazard and exposure scores of chemicals were listed by order of priority in accordance with GHS classification and exposure index data. Result: From the result of screening risk assessment for 642 chemicals, we extracted a list of 13 priority chemicals for HREC performed by the ISHA. A priority list of 27 chemicals which have carcinogen, mutagen and/or reproductive toxicity but not controlled by the ISHA was suggested for additional evaluation as "chemicals for special management".

• Journal of Environmental Health Sciences
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• v.45 no.2
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• pp.192-202
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• 2019

Objectives: According to the central limit theorem, the samples in population might be considered to follow normal distribution if a large number of samples are available. Once we assume that toxicity dataset follow normal distribution, we can treat and process data statistically to calculate genus or species mean value with standard deviation. However, little is known and only limited studies are conducted to investigate whether toxicity dataset follows normal distribution or not. Therefore, the purpose of study is to evaluate the generally accepted normality hypothesis of aquatic toxicity dataset Methods: We selected the 8 chemicals, which consist of 4 organic and 4 inorganic chemical compounds considering data availability for the development of species sensitivity distribution. Toxicity data were collected at the US EPA ECOTOX Knowledgebase by simple search with target chemicals. Toxicity data were re-arranged to a proper format based on the endpoint and test duration, where we conducted normality test according to the Shapiro-Wilk test. Also we investigated the degree of normality by simple log transformation of toxicity data Results: Despite of the central limit theorem, only one large dataset (n>25) follow normal distribution out of 25 large dataset. By log transforming, more 7 large dataset show normality. As a result of normality test on small dataset (n<25), log transformation of toxicity value generally increases normality. Both organic and inorganic chemicals show normality growth for 26 species and 30 species, respectively. Those 56 species shows normality growth by log transformation in the taxonomic groups such as amphibian (1), crustacean (21), fish (22), insect (5), rotifer (2), and worm (5). In contrast, mollusca shows normality decrease at 1 species out of 23 that originally show normality. Conclusions: The normality of large toxicity dataset was not always satisfactory to the central limit theorem. Normality of those data could be improved through log transformation. Therefore, care should be taken when using toxicity data to induce, for example, mean value for risk assessment.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.468-479
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• 2018

Objectives: Recently, a report was published that the humidifier disinfectant CMIT/MIT did not cause developmental toxicity and was not detected in systemic circulation as a result of an inhalation toxicity test. Therefore, this study was carried out to investigate any associations between CMIT/MIT exposure and developmental toxicity using the in vivo apical toxicity test method. Methods: Groups of pregnant ICR mice were instilled in the trachea with chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) using a visual instillobot over a period of seven days from days 11 to 17 days post-coitum. For the in vivo apical toxicity test method, an $LD_{50}$-based dose-range finding model was applied to decide the dose range for inducing developmental toxicity. Results: Among the groups of 0, 0.1, 0.5, 1.0, and 1.5 mg ai/kg/day CMIT/MIT, the exposure groups of 0.5 mg and 1.0 ai/kg/day CMIT/MIT were estimated to reflect the thresholds for the stillbirth and death of pregnant mice, respectively. The groups of 0.5, 1.0, and 1.5 mg ai/kg/day CMIT/MIT induced stillbirth rates of 2.57, 10, and 53.8%, respectively. Another exposure group of 0.75 mg ai/kg/day CMIT/MIT did not induce any deaths of pregnant mice and resulted in a stillbirth rate of 8% in only one of six pregnant mice. Conclusions: CMIT/MIT can induce stillbirth in pregnant mice. It was also concluded that CMIT/MIT moves through the pulmonary circulation system and then continues on through systemic circulation and the placenta. There is a possibility of stillbirth and other health causalities in humans beyond the lungs caused by CMIT/MIT exposure.

• Applied Biological Chemistry
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• v.47 no.1
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• pp.1-16
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• 2004

The purpose of this paper is to review the occurrence, analytical methods and reduction methods of aflatoxins in foods. Aflatoxins are produced by the secondary metabolism of various fungal species and have the highest toxicity among mycotoxins. Due to their toxicity including carcinogenic activity, aflatoxins affect not only the health of humans ana animals but also the economics of agriculture and food. As a food-importing country, because aflatoxins could contaminate raw commodities and foodstuffs, there should be inspection on the exposure and the regulation of risk assessment as a food safety measure. In addition, studies on rapid analytical methods and reduction of toxicity by various processes for aflatoxins should be carried out in conjunction with those of the risk assessment of aflatoxins.

• Toxicological Research
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• v.29 no.4
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• pp.221-227
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• 2013

Embryonic stem (ES) cells have potential for use in evaluation of developmental toxicity because they are generated in large numbers and differentiate into three germ layers following formation of embryoid bodies (EBs). In earlier study, embryonic stem cell test (EST) was established for assessment of the embryotoxic potential of compounds. Using EBs indicating the onset of differentiation of mouse ES cells, many toxicologists have refined the developmental toxicity of a variety of compounds. However, due to some limitation of the EST method resulting from species-specific differences between humans and mouse, it is an incomplete approach. In this regard, we examined the effects of several developmental toxic chemicals on formation of EBs using human ES cells. Although human ES cells are fastidious in culture and differentiation, we concluded that the relevancy of our experimental method is more accurate than that of EST using mouse ES cells. These types of studies could extend our understanding of how human ES cells could be used for monitoring developmental toxicity and its relevance in relation to its differentiation progress. In addition, this concept will be used as a model system for screening for developmental toxicity of various chemicals. This article might update new information about the usage of embryonic stem cells in the context of their possible ability in the toxicological fields.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.346-357
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• 2023

The purpose of this study is to suggest improvement plans for prevention regulations by reflecting the toxicity, fire and explosion effects of hazardous materials factories and surrounding areas using an off-site consequence assessment program. Regarding the effects of the hydrogen cyanide leak accident, which is the 1st petroleum of the 4th class flammable liquid, Areal Locations of Hazardous Atmospheres (ALOHA) program was used to compare and analyze the extent of damage effects for toxicity, overpressure, and radiation. As a result, the toxicity was analyzed to exceed 5km in the area with Acute exposure guideline level (AEGL)-2 concentration or higher, the overpressure was 103m in the range of 1 psi or more, and the radiant heat was analyzed to be 724m in the range of 2kw/m² or more. Toxicity and radiation affected the area outside the hazardous material storage area, but the overpressure was limited to the inside of the hazardous material storage area. Therefore, we propose to improve the safety management of hazardous materials by conducting a risk assessment for hazardous materials and reflecting the results in internal and external emergency response plans to prepare prevention regulations.

• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.44-54
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• 2018

Objectives: To protect individuals working at the site as well as the surrounding general population from a chemical accident, several emergency exposure guidance levels have been used to set a level of concern for certain chemicals. However, a level of concern has not been established for many substances that are frequently used or produced in large quantities in Korean workplaces. In the present study, we investigated the guidance levels for protecting populations from chemical exposure and the estimation of level of concern using acute inhalation and oral toxicity data. Methods: The number of chemicals to which emergency exposure guidance levels (e.g., ERPG-2, AEGL-2, PAC-2, and IDLH) can be applied were determined among 822 hazardous chemicals according to the 'Technical Guidelines for the Selection of Accident Scenarios (revised December 2016)'. The ERPG and AEGL values were compared across all three tiers for the 31 substances that appeared on both lists. We examined the degree of difference between the emergency exposure guidance levels and the estimates of level of concern calculated from acute inhalation or acute oral toxicity data. Results: Among the 822 hazardous chemicals, emergency exposure guidance levels can be applied to 359 substances, suggesting that the estimates of level of concern should be calculated using acute toxicity data for 56.3% of the hazardous chemicals. When comparing the concordance rates of ERPG and AEGL for 31 substances, the difference between the two criteria was generally small. However, about 40% of the substances have values diverging by more than three-fold in at least one tier. Such discrepancies may cause interpretation and communication problems in risk management. The emergency exposure guidance levels were similar to the estimates of level of concern calculated using acute inhalation toxicity data, but the differences were significant when using acute oral toxicity data. These results indicate that the level of concern derived from acute oral toxicity data may be insufficient to protect the population in some cases. Conclusion: Our study suggests that the development of standardized guidance values for emergency chemical exposure in the Korean population should be encouraged. It is also necessary to analyze acute toxicity data and fill the information gaps for substances that are important in Korean workplace situations.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.271-279
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• 2003

To investigate the toxicological effects of technical of IAP-3006, we performed subchronic oral toxicity study in Sprague-Dawley (SD) rats. In the subchronic dietary study, rats of both sexes were fed diets containing technical of IAP-3006 at concentrations of 0, 1000, 10,000, or 15,000 ppm for 90 days. No clinical signs and mortality were observed in animals treated with technical of IAP-3006 throughout the experimental period. There were also no significant changes in body weights, feed consumption, and any gross or histopathological lesions. Although there were statistically significant differences between the control and treated groups in some relative and absolute organ weights, and hematological and biochemical analyses, the data were in biologically normal ranges and did not show a dose-dependent manner. From these results, it is suggested that subchronic oral toxicity NOEL of technical of IAP-3006 in rats may be over 15,000 ppm.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.157-163
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• 2007

Tetrabromobisphenol A (TBBPA) is the most widely used BFR (brominated flame retardants) as a reactive flame retardant in printed circuit boards, and as additive applications in several types of polymers. The purpose of this study is to assess the adverse effects of TBBPA on the benthic amphipod (Hyalella azteca). Results on the acute toxicity of TBBPA using Hyalella azteca showed that NOEC and LOEC are 100mg/kg and 200mg/kg, respectively. In addition, when chronic toxicity of TBBPA was investigated at the concentration ranges between 0.01 to 100mg/kg, it was found that NOECs are $10mg/kg(fecundity){\sim}100mg/kg(viability)$, respectively. Significant fecundity inhibition was appeared at 100mg/kg of TBBPA, however, this concentration did not show severe adverse effect on weight increment. The values of PNEC were determined as 0.1mg/kg (fecundity) and 1mg/kg (lethal effect), respectively, using a safety factor suggested by EU and OECD.