• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.183-192
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• 2016

Silver nanomaterials have been intensively applied in consumer products of diverse industrial sectors because of their strong biocidal properties and reported to be hazardous to aquatic organisms once released in the environment. Nanomaterials including sliver, are known to be different in toxicity according to their physicochemical characteristics such as size, shape, length etc. However studies comparing toxicity among silver nanomaterials with different physicochemical characteristics are very limited. Here, toxicities of silver nanomaterials with different size (50, 100, 150 nm), length (10, $20{\mu}m$), shape (wire, sphere), and coating material (polyvinylpyrrolidone, citrate) using OECD test guidelines were evaluated in aquatic species (zebrafish, daphnia, algae) and compared. On a size property, the smaller of silver nanomaterials, the more toxic to tested organisms. Sphered type of silver nanomaterials was less toxic to organisms than wired type, and shorter nanowires were less toxic than longer ones. Meanwhile the toxic effects of materials coated on silver nanomaterials were slightly different in each tested species, but not statistically significant. To the best of our knowledge, it is first investigation to evaluate and compare ecotoxicity of silver nanomaterials having different physicochemical characteristics using same test species and test guidelines. This study can provide valuable information for human and environmental risk assessment of silver nanomaterials and guide material manufacturers to synthesize silver nanomaterials more safely to human and environment.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.621-629
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• 2014

This study aimed to evaluate the genotoxicity of GST (Gamisasangja-tang). For examining genotoxicity, we carried out bacterial reverse mutation assay, chromosome aberration assay, micronucleus induction test according to OECD guidelines. Bacterial reverse mutation assay: In GST treating group, regardless of existence S9 mix, revertant colonies counts appeared to be less than twice of negative control group and dose dependent increase. In positive control group, revertant colonies counts were shown to be more than twice of negative control croup. Chromosome aberration assay: All cell line showed repetition rate of abnormal chromosome aberration less than 5%, regardless of treating time, existence of S9 mix, and no significant change ($p{\succeq}0.05$) compared with negative control group. Micronucleus induction test: Micronucleated polychromatic erythrocytes (MNPCE) repetition rate of Polychromatic erythrocytes (PCE) showed no significant changes compared with negative control group ($p{\succeq}0.05$). PCE portion of total erythrocytes also showed no significant changes ($p{\succeq}0.05$). Our results showed that GST didn't induce any genotoxicity.

• The Korea Journal of Herbology
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• v.39 no.2
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• pp.19-25
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• 2024

Objectives : Jeopgoltang (JGT) is a new Korean herbal medicine formulation that is used to treat bone fractures. Although JGT is frequently used in clinical practice, there is a lack of scientific evidence on its safety. This study aimed to evaluate the preclinical toxicity of JGT using a single oral dose toxicity test in Sprague-Dawley (SD) rats. Methods : Five male and female rats per group were orally administered 1,250, 2,500, or 5,000 mg/kg of JGT after fasting for 12 h. Mortality and changes in clinical signs, body weight, and necropsy findings were monitored for 14 days according to the guidelines of the Korean Ministry of Food and Drug Safety and Organisation for Economic Co-operation and Development (OECD). Results : No significant clinical signs or mortality were observed after a single administration of up to 5,000 mg/kg. In addition, no significant necropsy findings related to JGT administration were observed. Conclusions: In conclusion, these results suggest that approximate Lethal Dose (ALD) of JGT on SD rats is over 5,000 mg/kg.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.650-657
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• 2011

The object of this study was to obtain acute information (single oral dose toxicity) of Taraxaci Herba (Dried total parts of Taraxacum platycarpum. H.Dahlstedt (Compositae)), has been traditionally used in Korean medicine for treating various inflammatory diseases. In order to observe the 50% lethal dose (LD 50), approximate lethal dosage (ALD) and target organs, test articles were once orally administered to female and male ICR mice at dose levels of 2,000, 1,000, 500 mg/kg according to the recommendation of Korea Food and Drug Administration Guidelines. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after single oral treatment of Taraxaci Herba aqueous extracts according to KFDA Guidelines with organ weights and histopathological observations of 12 types of principle organs. After single oral treatment of Taraxaci Herba aqueous extracts, we could not find any mortality and toxicological evidences up to 2,000 mg/kg treated group, the limited dosages in rodents at body and organ weights, clinical signs, gross and histopathological observations. Except for slight soft feces, which were detected in male mice treated with 2,000 mg/kg of Taraxaci Herba aqueous extracts at 1 day after end of treatment. The results obtained in this study suggest that the LD 50 and ALD of Taraxaci Herba aqueous extracts in both female and male mice after single oral treatment were considered as over 2,000 mg/kg because no mortalities were detected up to 2000 mg/kg that was the highest dose recommended by KFDA and OECD. However, it also observed that the possibility of digestive disorders, like diarrhea when administered over 2,000 mg/kg of Taraxaci Herba aqueous extracts in the present study, but these possibilities of digestive disorders can be disregard in clinical use because they ate transient in the highest dosages male only.

• The Korea Journal of Herbology
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• v.36 no.6
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• pp.27-37
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• 2021

Objectives : In the current study, we performed the 13-week repeated oral dose toxicity test and a 4-week recovery test of standardized Cornus officinalis Sieb. et Zucc. and Psoralea corylifolia L. 30 % ethanol extract (SCP) in Sprague-Dawley (SD) rats owing to aims for verifying no observed adverse effect level (NOAEL). Methods : The animal study was performed according to OECD guidelines for the testing of chemicals section 4 health effects test No.408 repeated dose 90-day oral toxicity study in rodents (03 October 2008). In the repeated dose toxicity study, SCP was orally administered to female and male rats at dose levels of 1,000, 2,000, and 4,000 mg/kg/day for 13-week. The control group and high dose (4,000 mg/kg/day) group were then monitored for 4 extra weeks to determine recovery time after the study period. 1) Results : Compared with the control group, there were no treatment-related adverse effects in clinical signs, body weight, hematology, serum biochemistry (Aspartate aminotransferase, Alanine aminotransferase, Alkaline phosphatase, 𝛾-Glutamyl transpeptidase, Blood urea nitrogen, Creatinine, Glucose, Total cholesterol, Total protein, Creatine phosphokinase, Albumin, Total bilirubin, Triglyceride, Inorganic phosphorus, Albumin/Globulin ratio, Calcium ion, Sodium ion, Potassium ion, Chloride ion), necropsy findings and organ weight (Ovary, Adrenal gland, Pituitary, Thymus, Prostate, Testis, Epididymis, Spleen, Kidney, Heart, Lung, Brain, Liver) at any dose tested. Conclusions : Taken together, these results suggest that the NOAEL of SCP in both genders was considered as over 4,000 mg/kg. Results from this study provide scientific evidence for the safety of SCP.

• Journal of Ecology and Environment
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• v.41 no.11
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• pp.318-327
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• 2017

Background: A typical sewage treatment plant is designed for organic and nutrient removal from municipal sewage water and not targeted to eliminate micropollutants such as pesticides, pharmaceuticals, and nano-sized metals which become a big concern for sustainable human and ecological system and are mainly discharged from sewage treatment plant. Therefore, despite contaminant removal by wastewater treatment processes, there are still remaining environmental risks by untreated pollutants in STP (sewage treatment plant) effluents. This study performed aquatic toxicity tests of raw wastewater and treated effluents in two sewage treatment plants to evaluate toxicity reduction by wastewater treatment process and analyze concentration of contaminants to reveal potential toxic factors in STP effluents. Methods: Water samples were collected from each treatment steps of two STPs, and acute and chronic toxicity tests were conducted following USEPA (United States Environmental Protection Agency) and OECD (Organization for Economic Cooperation and Development) guidelines. Endpoints were immobility for mortality and reproduction effect for estrogenicity. Results: Acute $EC_{50}s$ (median effective concentration) of influents for Seungki (SK) and Jungnang (JN) STPs are $54.13{\pm}32.64%$ and $30.38{\pm}24.96%$, respectively, and reduced to $96.49{\pm}7.84%$ and 100%. Acute toxicity reduction was clearly correlated with SS (suspended solids) concentration because of filter feeding characteristics of test organisms. Chronic toxicity tests revealed that lethal effect was reduced and low concentration of influents showed higher number of neonates. However, toxicity reduction was not related to nutrient removal. Fecundity effect positively increased in treated wastewater compared to that in raw wastewater, and no significant differences were observed compared to the control group in JN final effluent implying potential effects of estrogenic compounds in the STP effluents. Conclusions: Conventional wastewater treatment process reduced some organics and nutritional compounds from wastewater, and it results in toxicity reduction in lethal effect and positive reproductive effect but not showing correlation. Unknown estrogenic compounds could be a reason causing the increase of brood size. This study suggests that pharmaceutical residues and nanoparticles in STP effluents are one of the major micropollutants and underline as one of estrogenic effect factors.

• Korean Journal of Health Education and Promotion
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• v.23 no.5
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• pp.47-73
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• 2006

Objectives: This study aims to identify gaps between knowledge regarding migration and the spread of HIV/AIDS, to improve understanding of migrants with HIV/AIDS and their human rights, and to make suggestions for Korean policy makers to reform laws and policies towards granting migrants with HIV/AIDS more human rights and access to treatment and care. Methods: This study is based on an extensive literature review, questionnaire surveys and in-depth interviews from randomly selected 8 countries from 5 different continents: Japan from Asia; Australia from Oceania; Finland, Germany, Ireland and United Kingdom(UK) from Europe; and Canada and United States of America(USA) in North America. Results: This study has found that Korea has a discriminating policy regarding HIV/AIDS and foreigners. Classifying HIV/AIDS into a legal communicable disease, it requires a presentation of HIV/AIDS test results from foreigners wanting a long-term stay before entering. In principle, foreigners with HIV/AIDS cannot either enter or stay in Korea. If they are known infected with HIV/AIDS by any reason, they became to face an immediate deportation regardless of their sojourn statuses and purposes. Conclusion: With the results, this study suggests three reasons why Korean government needs to change the current HIV/AIDS policy on foreigners: 1) HIV-related travel restrictions have no public health justification, 2) its strict HIV/AIDS policy on foreigners could result in restriction on the mobility and migration of its people by the other countries, inversely, and 3) it needs to meet international guidelines and to observe conventions that international organizations suggest to maintain its status as a member of the international society.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.169-181
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• 2014

Objectives: The purpose of this study was to obtain information regarding classification and health hazards that may result from a 13-week inhalation exposure to 2-methylpentane by Sprague-Dawley rats. Materials: The testing method was conducted in accordance with OECD guidelines for the testing of chemicals No. 413. The rats were divided into four groups(ten male and ten female rats in each group) and exposed to 0 ppm, 290 ppm, 1,160 ppm, 4,640 ppm 2-Methylpentane in each exposure chamber for six hours per day, five days per week, for 13 weeks. Results: No death or particular clinical presentation including weight change and change of feed rate was observed. The relationships between dose, gender and response were also not significantly changed in urinalysis, hematologic examination, or biochemical examination of blood(except for total cholesterol being up, total protein being up, and chloride ion being down in males), and blood coagulation time. For the relative weight measurement of organs, in the male group the weight change of both kidney and liver were increased in proportion to dose. In histopathological examination, nephropathy in the kidney(cystic change of renal tubules, regenerative tubule, inflammatory cell infiltration and necrosis in the interstitial tissue) was increased in a dose-dependent manner in the male group(290 ppm, 1,160 ppm, 4,640 ppm). However, other organs were not affected by the test substance. Conclusions: 2-methylpentane was estimated as a chemical causing nephropathy in the male group. NOAEL(No Observable Adverse Effect Level) in the female group is more than 4,640 ppm, while inthe male group it is less than 290 ppm.

• Safety and Health at Work
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• v.3 no.3
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• pp.224-234
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• 2012

Objectives: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. Methods: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. Results: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. Conclusion: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).

• Applied Biological Chemistry
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• v.43 no.2
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• pp.130-135
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• 2000

Photodegradation rate of flupyrazofos in aqueous solution were measured under various test conditions mainly following the guidelines of U.S. EPA and OECD. It was observed that the flupyrazofos was degraded by simple hydrolysis but not degraded by light in pure water. Using acetone as a known photosensitizer, the minimal concentration of acetone needed to photo-degrade the flupyrazofos in % and molar terms were 0.047% and 0.006, respectively. When treated with acetone, it was also found that the ringlet oxygen is a very effective photo oxidant in the degradation of flupyrazofos, but the effect of hydroxyl radical was not observed at the treatment level of hydroxyl radical, isopropylbenzene. In an actinometer experiment, quantum yield of flupyrazofos (0.4 ppm with 2% acetone) was $17.66{\times}10^{-5}$ and degradation rate and half-life were 0.038/hr and 18.2 hours, respectively.