• 한국환경과학회지
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• 제4권5호
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• pp.61-61
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• 한국환경과학회지
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• 제4권5호
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• pp.447-459
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• Molecular & Cellular Toxicology
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• 제4권4호
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• pp.267-277
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• 2008

Benzene and ethylbenzene (BE), the volatile organic compounds (VOCs) are common constituents of cleaning and degreasing agents, paints, pesticides, personal care products, gasoline and solvents. VOCs are evaporated at room temperature and most of them exhibit acute and chronic toxicity to human. Chronic exposure of benzene is responsible for myeloid leukemia and also ethylbenzene is also recognized as a possible carcinogen. To evaluate the BE effect on human, whole human genome 35 K oligonucleotide microarray were screened for the identification of the differential expression profiling. We identified 280 up-regulated and 201 down-regulated genes changed by more than 1.5 fold by BE exposure. Functional analysis was carried out by using DAVID bioinformatics software. Clustering of these differentially expressed genes were associated with immune response, cytokine-cytokine receptor interaction, toll-like signaling pathway, small cell lung cancer, immune response, apoptosis, p53 signaling pathway and MAPKKK cascade possibly constituting alternative or subordinate pathways of hematotoxicity and immune toxicity. Gene ontology analysis methods including biological process, cellular components, molecular function and KEGG pathway thus provide a fundamental basis of the molecular pathways through BEs exposure in human lymphoma cells. This may provides a valuable information to do further analysis to explore the mechanism of BE induced hematotoxicity.

• 대한약침학회지
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• 제25권4호
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• pp.354-363
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• 2022

Objectives: This study aimed to assess the adverse effects of Rasaraj Rasa tablets after repeated oral administration for 180 days in Wistar rats. Methods: Wistar rats were divided into five groups, of which three were treated with 54, 162, and 270 mg/kg body weight of Rasaraj Rasa, respectively, which correspond to one, three, and five times the proposed human therapeutic dose, for 180 days consecutively. The fifth group (satellite) also received 270 mg/kg body weight of Rasaraj Rasa for 180 days. Body weight and food intake were measured weekly. At the end of the study, all rats were sacrificed, and their blood, serum, and organs were collected and examined using hematology, serum biochemistry, gross pathology, and histopathology tests. In contrast, the satellite group was kept for 4 weeks after treatment. Results: No significant treatment-related toxicological findings were observed in the clinical features, body weight, laboratory findings, and pathological findings of the high-dose treated groups, when compared to those of the control group. Conclusion: The no-observed-adverse-effect-level for Rasaraj Rasa in Wistar rats is set at 270 mg/kg body weight.

• 농업과학연구
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• 제28권1호
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• pp.33-40
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• 2001

아직까지 시도된 바 없는 살균성 phenylthionocarbamate 유도체들의 phenyl-치환기가 변화함에 따라 TOPKAT 계산으로 예측된 다양한 급성 및 만성 독성값에 미치는 정량적인 분자구조와 독성과의 관계 (QSTRs)를 검토한 결과는 다음과 같다. (1) 기질분자의 구조변화에 따른 독성치와 그의 판별점수 (D.S.) 에 기초하여 분자 중 특정부분 (fragment)이 양 (+)의 값으로 독성에 기여하는 대체적인 순서는 Aro. C=C, -O-, -NH- 및 할로겐 (X) 원자의 순이었다. (2) 대부분의 화합물들은 매우 높은 돌연변이와 발암성이 예측되었으며 특히, 치환기의 위치에 관계없이 fluoro-치환체는 $B_2$상수에 따른 입체효과 ($(B_2)_{opt.}=1.54{\AA}$)에 의하여 모두 100% 돌연변이를 발현한 반면에 trifluorornethyl-치환체는 돌연변이 발현 가능성이 전혀 없었다. (3) 가장 높은 독성 발현조건은 phenyl-치환기에 대한 소정의 적정값으로 돌연변이성에는 $(B_2)_{opt.}=1.54{\AA}$, 발암성에서 수컷 rat와 mouse는$(R)_{opt.}=0.16$ 및 $(\pi)_{opt.}=0.16$ 그리고 rat의 경구독성은 $LD_{50};({\varepsilon}LOMO)_{opt}=-0.52e.v.$, chronic LOAEL; $(B_3){opt.}=1.54{\AA}$, 어독성은 ${LC_50}$; $(logP)_{opt.}=4.25$ 및 물벼룩에 대한 독성은 $EC_{50};({\sigma})_{opt}=-0.68$를 나타내는 경우 이었다. (4) 돌연변이성에는 할로겐 중, fluoro-기를 위시하여 nitro 및 methyl-기 등의 순서로 기여하였고 phenyl 고리 상, 치환기의 위치와 전자 수수관계에는 대체로 무관한 경향을 나타내었다.

• 한국발생생물학회지:발생과생식
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• 제19권4호
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• pp.167-180
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• 2015

Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children's health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.11.1-11.6
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• 2016

Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor ("Survey on the work environment") and by the Ministry of Environment ("Survey on the circulation amount of chemicals"). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be $0.990mg/m^3$, as compared to the threshold exposure level of $5mg/m^3$. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below $5mg/m^3$ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

• Toxicological Research
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• 제16권4호
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• pp.293-301
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• 2000

Toxicity of a combined preparation of ticlopidine and ginkgo biloba extract (EGb 761) in a ratio of 10: 4 was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance intragastrically at a dose of 0 mg/kg, 17 mg/kg, 52 mg/kg or 156 mg/kg for 91 consecutive days. No death or abnormal clinical sign was observed throughout the administration period. There was no difference in body weight gain, food intake or water consumption among different dose groups. Test sub-stance-related differences were not observed in urinalysis. In hematological results mean corpuscular hemoglobin (MCH) of low and high dose male group was increased. Prothrombin time of medium and high dose female group was decreased. A significant increase in serum total cholesterol was observed in both sexes of rats treated with a daily dose of 156 mg/kg, but all the other values obtained in serum chemistry appeared to be within normal ranges. A dose dependent increase in the relative liver and kidney weights was observed in both male and female rats. There were no gross pathological findings at terminal sacrifice. Microscopic histopathological examination did not show any lesion associated with administration of the test substance. The results suggest that under the conditions employed in this study no observable effect level (NOEL) of the test substance be greater than 17 mg/kg/day, but less than 52 mg/kg/day.

• Environmental Analysis Health and Toxicology
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• 제23권1호
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• pp.17-22
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• 2008

A rapid, inexpensive enzymatic method is proposed for indirect water quality testing in terms of heavy metal toxicity. The activity of glucose-6-phosphate dehydrogenase was applied for heavy metal toxicity test as an effective criterion in water quality. The toxicity of Pb (lead) and Cd (cadmium) for water flea, Moina macrocopa, were evaluated for $2{\sim}8\;days$ with variables of mobilization ability. And the reproduction impairment of Moina macrocopa were investigated as the parameter of chronic toxicity twst for Pb and Cd. As a result, the $EC_{50}$ for immobilization of Moina macrocopa were Pb and Cd were 1.6749 and 0.4683, respectively. The values of reproducive impairment to Moina macrocopa for Pb and Cd were 9.5938 and 8.3264 in $EC_{50}$. A significant alteration of G6PDH (Glucose-6-phosphate dehydrogenase) activity of Moina macrocopa was observed when Cd and Pb were treated in media. The results obtained indicate that G6PDH activity of Moina macrocopa can be used as an indicative parameter in aquatic toxicity tests for heavy metals.

• Biomolecules & Therapeutics
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• 제6권2호
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• pp.171-181
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• 1998

DA-3585, a biosynthetic recombinant human erythropoietin has been developed as a treatment for anemia associated with chronic renal failure in Dong-A pharmaceutical Co. Ltd. This study was carried out to assess its acute and subacute toxicities in rabbits. DA-3585 was intravenously administered to rabbits at dose levels of 6250, 12500 or 25000 lU/kg for single dose toxicity study and at dose levels of 100, 500 or 2500 lU/kg/day for 4-week repeated dose toxicity study. In the acute toxicity study, dose up to 25000 lU/kg had no adverse effect on the behavior or body weight gain. Pathological examinations revealed no abnormal gross lesions related to DA-3585. In the subacute toxicity study, all animals survived until termination of treatment. DA-3585 had no influence on clinical signs, food and water intake or on body weight changes. Hematological examination showed increases in the number of RBC, hemoglobin contents and hematocrit values with a dose dependent manner in the animals treated with DA-3585. Histopathological examination revealed erythroid hyperplasia in the bone marrow and extramedullary hematopoiesis in the liver. The changes detected in the hematological and histopathological examination presumably represent exaggerated pharmacological effects of erythropoietin. The NOAEL (no-observed-adverse-effect-level) of DA-3585 was estimated to be 100 lU/kg/ day under this study condition.