• 한국산업보건학회지
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• 제28권1호
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• pp.80-90
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• 2018

Objectives: This study was performed to propose a domestic occupational exposure limit(OEL) following a health hazard assessment, calculation of a non-carcinogenicity reference concentration worker($RfC_{worker}$) value, and examination of international agencies' exposure limits. It also recommends legal management within the Occupational Safety and Health Act for HCFC-123, which caused an acute hepatotoxicity incident. Methods: An acute hepatotoxicity incident due to the fire extinguishing agent HCFC-123 was investigated. Toxicological hazard and health hazard classifications were examined and a non-carcinogenicity $RfC_{worker}$ value was calculated for HCFC-123. An OEL and the necessity of legal management were recommended as well. Results and Conclusions: An OEL for HCFC-123 of 10 ppm($62.5mg/m^3$), which considered the $RfC_{worker}$ value, 5.56 ppm, produced in dose-response assessment and the exposure level of 19.1-20.9 ppm measured as an eight-hour TWA(time-weighted average) in the incident place, is recommended. HCFC-123 is urged to be included as a chemical requiring legal management in the Occupational Safety and Health Regulations. In addition, it is recommended that a peak exposure of ACGIH be adopted in the Notice of the Ministry of Employment and Labor.

• Journal of Radiation Protection and Research
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• 제42권3호
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• pp.146-153
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• 2017

Background: Acute radiation syndrome (ARS) primarily refers to damage to the hematopoietic system, myeloid system, and gastrointestinal (GI) system caused by radiation exposure. Such damage progresses to become life-threatening. In particular, as the syndrome develops very rapidly-within several hours from radiation exposure-prompt and accurate diagnosis and treatment are needed, as is further research into appropriate diagnostic and treatment modalities. Materials and Methods: Minipigs, which display human-like properties, underwent whole-body irradiation at 2 or 4 Gy (doses causing hematopoietic ARS) or at higher doses of 7 or 12 Gy. Changes in the blood cells and clinical symptoms were analyzed and we performed a necropsy when the animals succumbed to ARS. Results and Discussion: The minipig irradiated with 2 Gy showed a decrease in white blood cells, including neutrophils, lymphocytes, and platelets in the early stages. However, the blood cell counts gradually increased and returned to normal values. The minipig irradiated with 4 Gy succumbed due to hematopoietic ARS. In contrast, the minipigs irradiated with 7 or 12 Gy exhibited clinical symptoms of combined GI damage and hematopoietic syndrome. Moreover, a characteristic pattern of platelet changes was observed in the 7 and 12 Gy irradiated minipigs. Conclusion: The changes in the platelet count caused by radiation exposure observed in minipigs, which are hematologically and pathohistologically similar to humans, suggest that they can be used as a novel diagnostic criterion.

• Fisheries and Aquatic Sciences
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• 제23권8호
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• pp.23.1-23.10
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• 2020

This study was conducted to evaluate the acute effects of waterborne cadmium exposure on bioaccumulation and antioxidant enzymes in eels (Anguilla japonica) and to determine the median lethal concentration (LC₅₀). Fish were exposed to different cadmium concentrations (0, 0.15, 0.30, 0.61, 1.83, 3.08, 3.67, 4.29, and 5.51 mg L^-1) for 96 h. The LC₅₀ of A. japonica to cadmium was 3.61 mg L^-1. Cadmium accumulation generally increased in tissues with increasing waterborne cadmium concentrations. At ≥ 1.83 mg L^-1 exposure, all tissues accumulated significant cadmium concentrations compared with the control group, in the order of kidney > liver > gill > spleen > muscle. Measurements of variation in actual cadmium concentrations showed that a reduction of the metal in experimental water was related to cadmium accumulation in tissues. As activity alteration of antioxidant enzymes for reactive oxygen species, superoxide dismutase and catalase activities increased at ≥ 0.61 mg L^-1 significantly, glutathione peroxidase and glutathione S-transferase activities were not significantly changed. The results of this study suggest that acute exposure to waterborne cadmium is potentially fatal to A. japonica due to the metal's major accumulation in various tissues and the effect of antioxidant enzyme activity.

• Journal of Veterinary Science
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• 제24권2호
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• pp.22.1-22.12
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• 2023

Background: Citric acid (CA) and sodium hypochlorite (NaOCl) have been used to disinfect animals to protect them against avian influenza and foot-and-mouth disease. Objectives: We performed a good laboratory practice (GLP)-compliant animal toxicity study to assess the acute toxic effects of CA and NaOCl aerosol exposure in Sprague-Dawley rats. Methods: Groups of five rats per sex were exposed for 4 h to four concentrations of the two chemicals, i.e., 0.00, 0.22, 0.67, and 2.00 mg/L, using a nose-only exposure. After a single exposure to the chemicals, clinical signs, body weight, and mortality was observed during the observation period. On day 15, an autopsy, and then gross findings, and histopathological analysis were performed. Results: After exposure to CA and NaOCl, body weight loss was observed but recovered. Two males died in the CA 2.00 mg/L group and, two males and one female died in the 2.00 mg/L NaOCl group. In the gross findings and histopathological analysis, discoloration of the lungs was observed in the CA exposed group and inflammatory lesions with discoloration of the lungs were observed in the NaOCl exposed group. These results suggest that the lethal concentration 50 (LC50) of CA is 1.73390 mg/L for males and > 1.70 mg/L for females. For NaOCl, the LC50 was 2.22222 mg/L for males and 2.39456 mg/L for females. Conclusions: The Globally Harmonized System is category 4 for both CA and NaOCl. In this study, the LC50 results were obtained through a GLP-based acute inhalation toxicity assessment. These results provide useful data to reset safety standards for CA and NaOCl use.

• Toxicological Research
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• 제13권3호
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• pp.237-245
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• 1997

As the development of a pharmaceutical product is a dynamic process which involves continuousfeed-back between non-clinical and clinical studies, the integration of pharmacokinetics into toxicity testing became increasingly important in recent years. Toxicokinetic measurements in the toxicity studies is considered to be an important scientific approach in the interpretation of the toxicology findings and the promotion of rational study design development. Primarily this research project was conducted to determine the systemic exposure achieved in acute toxicity test and its relationship to dose level and the time course of the toxicity study. Acute hepatotoxicity study and its relevant toxicokinetic study in mice were performed using acetarninophen (AA) as a model compound. The correlation between acute hepatotoxicity indices and toxicokinetic parameters following intraperitoneally administration of various dosages of AA in mice was evaluated and discussed minutely in the text. Based on these studies, single-dose toxicity testing of AA including kinetic studies was evaluated in ICR mice for 7 days and interpreted in the text. Our results from the integration of toxicokinetic monitoring into single-dose toxicity study enable to elucidate the relation of the exposure achieved in toxicity study to toxicological findings and assist in the selection of appropriate dose levels for use in repeated-dose toxicity or later studies.

• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.271-277
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• 2007

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are fully flurorinated organic compounds which are highly persistent in environment and accumulated in organism. These chemicals are released to the environment at their manufacture, during their use in industrial and consumer applications and from disposal after their use. The purpose of this study was to determine the effects of PFOA and PFOS on the freshwater flea (Moina macrocopa). Acute toxicity test and chronic toxicity test were performed for 2 days and 10 days, respectively. Acute toxicity was assessed on the basis of mortality, while chronic toxicity was assessed by fecundity as well as mortality. The acute toxicity studies on PFOA and PFOS showed that the values of $LC_{50}$ were $73.9\;mg/L\;and\;27.7\;mg/L$ respectively. In the chronic toxicity test, fecundity was reduced significantly at 24.1 mg/L of PFOA and 9.3 mg/L of PFOS, respectively. Conclusively, the results of this work suggest that Moina macrocopa could be a suitable model organism for screening and assessing of environmental pollutants in water.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1373-1376
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• 2000

The peroxidation status of tissues was estimated in broilers under acute or chronic heat stress ($32^{\circ}C$, 24 h, $5{\times}24h$) in the present study. The results showed that the lipid peroxide (LPO) concentrations in plasma and liver were elevated (p<0.05) by acute heat stress, and were not influenced in kidney (p>0.05). At the same time, no significant change of superoxide dismutase (SOD) activity in the liver, kidney or plasma was observed. Under chronic heat exposure, the SOD activity in liver was increased (p<0.05) and the LPO concentrations in the liver and plasma were restored to the normal levels. The LPO level in kidney was not affected by chronic heat stress (p>0.05), but SOD activity was significantly decreased (p<0.01). The results suggested that the peroxidation was induced by acute heat stress and disappeared along with the time of heat exposure, and the peroxidation reactions were different among tissues.

• 한국환경보건학회지
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• 제47권2호
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• pp.166-174
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• 2021

Objectives: This study aimed to provide temporal Acute Exposure Guideline Levels (AEGL) for a hazardous substance as a pilot study. Methods: As one of the substances designated by the Korea Ministry of Environment as requiring preparations for potential accidents, formaldehyde was selected to estimate the AEGLs. The calculation was based on Haber's formula (Cn×t=k) using valid toxicity data (for humans/animals). A total of 96 points of AEGL levels were provided using an interval of five minutes over eight hours. Results: The AEGL-1 and 2 values were constant for the entire exposure duration at 0.9 ppm and 14 ppm, respectively. The values were obtained from clinical/animal tests, and the adaptation effect after a given exposure duration was also considered. AEGL-3 was based on animal toxicity data, and it was estimated from 127 ppm for the initial five minutes to 35 ppm for eight hours. Conclusions: More specific AEGL levels for formaldehyde could be obtained in this study using toxicity data with Haber's formula. Based on this methodology, it would be also possible to estimate AEGL levels that can be used at the scene of a chemical accident for other substances requiring preparation for potential accidents.

• 농약과학회지
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• 제18권2호
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• pp.95-103
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• 2014

본 연구에서는 우리나라에서 재배된 과채류 8작물 중 유기인계 농약의 잔류량을 모니터링 한 후 급성 및 만성 노출평가를 시행하고 독성등가치를 이용하여 누적 및 통합노출량을 산출하고 그 위해성을 확인하였다. 과채류 8종에서 검출된 유기인계 농약은 chlorpyrifos, EPN, methidathion, phosphamidon 4종이었다. 급성평가인 NESTI의 누적량은 가지, 토마토, 호박, 오이 순으로 높게 나타났다. 또한, 만성 노출평가의 제1단계로 과채류 8종의 총 TMDI는 ADI의 76.14%에 해당하였으며, 만성 노출평가의 제2단계인 NEDI의 총 노출량은 ADI 대비 13.949%에 해당하였다. 만성 노출평가의 제3단계로 과채류 8종 섭취에 따른 노출량을 확률적으로 평가한 결과, 총 노출량이 ADI 대비 0.0001%로 매우 낮게 나타났다. 이상의 결과를 볼 때 우리나라 일반인이 과채류 8종을 섭취함으로써 유기인계 농약에 노출되는 수준은 매우 안전한 것으로 확인되었다. 향후 대상작물을 농산물 전체로 확대하고 대상집단을 어린이와 같은 subgroup으로 추가할 필요가 있을 것으로 생각된다.

• 환경생물
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• 제38권1호
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• pp.40-46
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• 2020

본 실험에서 암모니아 급성 노출은 대왕범바리의 혈액학적 성상 및 혈장 성분에 유의적 변화를 나타내었다. 본 실험의 결과 20mg L^-1 이상의 급성 암모니아 노출은 대왕범바리의 혈액학적 성상 및 혈장 성분에 영향을 주어 생리적 변화를 일으키며, 40mg L^-1의 급성 암모니아 농도는 대량 폐사를 유발할 수 있음을 나타낸다. 향후 대왕범바리 바이오플락 양식기술 적용을 위한 양식연구에 이러한 결과를 지표로 활용할 수 있을 것이다.