• 한국산업보건학회지
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• 제33권1호
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• pp.1-2
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• 2023

2-Bromopropane, a causative chemical that caused the outbreak of reproductive toxicity 28 years ago, was classified as Group 2A in the recently held IARC monograph 133 meeting. Korean research data were used as supporting data in the carcinogenicity evaluation of 2-bromopropane and other carcinogens. I would like to share my memories with the researchers at the Occupational Safety and Health Research Institute who worked hard to identify the cause.

• 한국응용과학기술학회지
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• 제21권4호
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• pp.364-369
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• 2004

It has been confirmed that some Trihalomethanes (THMs) suspected as carcinogens, can be formed during chlorination for water supply through the reaction of chlorine and humic substances in water. The electrochemical characteristics on activated carbon fiber filter (ACF) electrode were investigated to remove the THMs in the chlorination process of drinking water. The electrochemical removal efficiency depended on the applied voltage and flow rate. In this study, the best result showed that the removal efficiency of THMs was higher than 99%.

• Bulletin of the Korean Chemical Society
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• 제7권3호
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• pp.183-185
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• 1986

Self-atom polarizability were calculated for 17 polycyclic aromatic hydrocarbons and their metabolites by LCAO-MO method and examined the relation with the carcinogenicity. It has been found that ${\pi}_{1.2.4}$, the sum of self-atom polarizability of 1, 2 and 4 positions forming trans-butadiene frame in a compound, agree quite well with the observed carcinogenic activity, and also, ${\pi}_{1.2.4}$ value increase with the metabolic activiting in agreement with the experimental facts that parent carcinogens activated with metabolism. Accordingly, we suggest that the 1, 2 and 4 positions in the carcinogenic compounds play the most important role in the process of chemical carcinogenesis, and also self-atom polarizability, as one of theoretical reactivity indices, is to be used as a measure of carcinogenic activity.

• Toxicological Research
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• 제16권1호
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• pp.9-16
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• 2000

Ginseng (the root of Panax ginseng C. A. Meyer, Araliaceae) has been used for traditional medicine in China, Korea, Japan and other Asian countries. It is most often used as a general tonic, and it involves a wide range of pharmacological actions, such as antiaging, adaptogen-like effect to foreign deleterious infringement, immunoenhancement, antistress, antitumor, and antioxidant actions. Red ginseng showed anticarcinogenic activity against various chemical carcinogens in mouse and cancer-preventive effect of human being as on mice in experimental and epidemiological studies. In the present study, we have found the protective properties of red ginseng against vinyl carbamate (VC) which is the proximate carcinogen of ethyl carbamate and its ultimate carcinogenic epoxides. Red ginseng exhibited dose-dependent inhibition on the mutagenci activities of boty VC in the presence of S9 mix and vinyl carbamate epoxide (VCO) without metabolic activation in Salmonella typhimurium TA1535. Formation of DNA adducts from VCO was also attenuated in the presence of red ginseng. Oral administration of red ginseng prior to the topical application of each of the above carcinogens and TPA treatment resulted in significant reduction in both incidence and multiplicity of skin tumors in mice. These results indicate that red ginseng possesses a strong chemopreventive effect against mouse skin carcinogenesis induced by VC or VCO.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(환경)
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• pp.450-468
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• 1994

Scientists have long used conventional toxicological methods to establish 'safe levels of exposure' for chemicals presumed to have threshold health effects or doses below which significant effects are unlikely to occur. These same methods cannot be used to establish safe levels of exposure for non-threshold pollutants. such as carcinogens. Therefore. Federal regulatory agencies in the United States are using risk assessment methods to provide information for public health policy decisions concerning increases in risk associated with increases in exposure to carcinogenic and other non-threshold pollutants. Acceptable exposure/risk levels are decided by policymakers who consider descriptions and estimates of risks together with social and economic benefits from the uses of the chemical. 1bis paper focuses on the development of quantitative risk assessment approaches by Federal regulatory agencies in the United States, and identifies the mathematical models currently being used for risk extrapolation. including their inherent uncertainties. The uncertainties and limitations of these methods have led some scientists to question the utility of quantitative risk extrapolation. The experience of the; U.S. Environmental Protection Agency (EPA). as summarized in this paper. can provide a realistic basis for evaluating the pros and cons. Finally. shortcomings in current risk assessment methods and their use in policy decisions are explored. and areas for possible improvement. given current scientific knowledge. are identified.

• Toxicological Research
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• 제17권
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• pp.41-45
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• 2001

The methods used for risk assessment from exposure to chemicals are well established. in most cases where toxicity other than carcinogenesis is being considered, the standard method relies on establishing the No Observed Adverse Effect Level (NOAEL) in the most sensitive animal toxicity study and using an appropriate safety factor (SF) to determine the exposure which would be associated with an acceptable risk. For carcinogens a different approach is used because it has been argued there is no threshold of effect. Thus mathematical equations are used to extrapolate from the high doses used in ani-mal experiments. These methods have been strongly criticised in recent years on several grounds. The most cogent criticisms are a) the equations are not based on a thorough understanding of the mechanisms of carcinogenesis and b) the outcome of a risk assessment based on such models varies more as a consequence of changes to the assumptions and equation used than it does from the data derived from carcinogenicity experiments. Other criticisms include the absence of any measure of the variance on the risk assessment and the selection of default values that are very conservative. Recent advances in the application of risk assessment emphasise that measures of both the exposure and the hazard should be considered as a distribution of values. The outcome of such a risk assessment provides an estimate of the distribution of the risks.

• 한국식품영양학회지
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• 제23권2호
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• pp.276-284
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• 2010

The effects of different dietary fatty acids on the hepatic glutathione S-transferase(GST-P) positive foci and glutathione related enzyme system were investigated in carcinogen treated rats. Weaning male Sprague Dawley rats were divided into three groups and fed the diets of 15% corn(CO), perilla(PO), and sardine oil(SO), respectively. Hepatocellular carcinogenesis was initiated with diethylnitrosamine(DEN) and then fed the diet containing 0.02% 2-acetylaminofluorene(2-AAF) followed by 0.05% phenobarbital for 10 weeks. The hepatic tissues were homogenized and centrifugated to prepare microsomal and cytosolic fractions. The enzyme activities of hepatic glutathione S-transferase(GST), glutathione reductase(GR), and glutathione peroxidase(GPx) were determined from cytosolic fractions. The number of GST-P hyperplastic nodules was the highest in corn oil group at 6th week, the early stage of hyperplastic nodule formation. GST activities were increased significantly by carcinogens in all dietary groups after 6th wk. GR activities followed the same trend as GST activities. GPx activities were decreased by carcinogens in all dietary groups at 10th week. In this experiment, corn oil diet may have promotive effect on hyperplastic nodule formation during the early promotional stages of chemical carcinogenesis.

• Toxicological Research
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• 제21권1호
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• pp.1-14
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• 2005

Transgenic mouse models have been introduced and accepted by regulatory bodies as an alternative to carcinogenicity assay models to predict and evaluate chemical carcinogens. The recent research outcomes in transgenic mouse models have made progressive advances in the understanding of chemical carcinogenesis and the evaluation of potential human carcinogens. However, these models still remain to be insufficient assay systems although the insufficiencies have been recognised and are being resolved. Based on up to date information from literature, this review article intends to understand currently accepted transgenic mouse models, issues arising from study design, interpretation of the study, results of validation project and their cancer prediction rate, and further perspectives of cancer assay models from the regulatory view point.

• 한국산업보건학회지
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• 제33권1호
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• pp.40-49
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• 2023

Objectives: The handling of carcinogenic, mutagenic or reproductive toxic (CMR) materials in paint-related products used by automobile maintenance companies in Busan was investigated and its characteristics were analyzed. Methods: MSDS for paint-related chemical products used by automobile repair companies in Busan were collected and the manufacturers, product uses, names of chemical substances in each component, CAS numbers, content, and more were listed. Results: As a result of collecting MSDS on 4,800 kinds of products handled in the painting process of automobile repair companies in Busan and comparing them with the latest toxic information database, 60 out of a total of 438 substances were found as CMR materials. Seven carcinogens (1A), including quartz, benzene, formaldehyde, and hexavalent chromium, were present. Two reproductive toxic 1A substances were included: hexavalent chromium in paint pigments and lead. Conclusions: Most of the products (95.5%) were found to contain at least of one CMR component, so it was judged that a study on exposure assessment of CMR substances by automobile maintenance workers is needed in the future.

• 한국산업보건학회지
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• 제10권1호
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• pp.1-17
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• 2000

Carcinogen-DNA adduct analysis has potential for biomonitoring the earliest effects of exposure to many chemical carcinogens. They are the covalent reaction products of electrophiles and nucleophilic sites on DNA and the initial damage to DNA induced by many carcinogens. So many researchers begin to use them as biomarker for monitoring the earliest exposure of carcinogens and develop the effective analytical techniques about them. Randerath, Gupta and coworkers(1981, 1982) has also developed a $^{32}P$-postlabelling method as one among them. A major project for biomonitoring workers with carcinogen-DNA adducts is to develop non-invasive samples instead of tissues of target organs such as baldder and lung. This study use the exfoliated urothelial cells in urine for examine benzidine-DNA adducts. The content of exfoliated urothelial cells is not enough to significantly measure DNA content with spectrophotometer, and require the another way. So firstly washing the collected cells with PBS and 70% ethanol and centrifuge them for removing the crystals in urine, which block the isolation of DNA adducts. And then, measure the total nucleotide after $^{32}P$-postlabelling for calculating RAL. $[{\gamma}-^{32}P]ATP$ using for $^{32}P$-postlabelling, can synthesize with $[^{32}P]H_3PO_4$, and reagent and enzyme mixture (RM, EM), which is very economic in case of requiring a lot of them. Chromatography was composed of two steps. First step was to separate adduct ones from unadducted nucleotide, and secondary step was separate each adduct, which were performed with 4 kinds of solvents and different directions on TLC. With this procedure, we measure the DNA adducts in exfoliated urothelial cells of workers who were employed in benzidine and benzidine-dye company. RAL of adducts were $89.0{\times}10^7$ and $57.0{\times}10^7$ in them. In conclusion, we can significantly measure the DNA adduct in exfoliated urothelial cells by using the above $^{32}P$-postlabelling procedures, and use them to be biomonitoring workers who exposed carcinogens.