• Asian Journal of Atmospheric Environment
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• 제5권4호
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• pp.247-262
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• 2011

This study assessed the health risks of childhood exposure to PBDEs via different possible pathways in children's facilities and indoor playgrounds. When PBDE contamination was measured, it was determined through multiple routes, including inhalation of indoor dust, dermal contact with product surfaces and children's hands, and incidental dust ingestion. Samples were collected from various children's facilities (playrooms, daycare centers, kindergartens, and indoor playgrounds) during summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). The hazard index (HI) was estimated for non-carcinogens, and PBDEs, such as TeBDE, PeBDE, HxBDE, and DeBDE, were examined. The sensitivity to the compounds did not exceed 1.0 (HI) for any of the subjects in any facility. However, current data about toxicity does not reflect effects that were fully sensitive in children, so there is uncertainty in the dose-response data. The contribution rates of PBDEs were 71.4 to 96.1% and 3.7 to 28.2% for intake and inhalation exposure, respectively, indicating that intake of floor dust and inhalation are the primary routes.

• Environmental Analysis Health and Toxicology
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• 제20권3호
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• pp.215-221
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• 2005

Environmental polycyclic aromatic hydrocarbones (PAHs), which are formed during incomplete combustion of fossil fuels, are widely distributed in our environment. Human exposure to PAHs may occur through smoking, polluted air, food consumption and occupational contact. Urinary naphthols, 1-and 2-naphthol, have been suggested as route -specific biomarkers for exposure to airborne PAHs. Cytochrome p450 2E1 (CYP2E1) is known to be a great importance for the metabolism of organic solvents, which is a precacinogens with small molecular weight. This study describes the metabolic differences between PstI and RsaI polymorphisms (c1 allele: PstI-. RsaI+ ; c2 allele: PstI+, RsaI-) of CYP2E1 5-flanking region by genetically modified HepG2 cells, which overexpress the polymorphic regions. The results of CAT assay and western blot in the c2 allele overexpressed cells have higher activities than the cl allele over-expressing cells. However, the metabolism of naphthalene to 2-naphthol has no difference due to the two genotypes. In this study, we established the CYP2E1 polymorphic allele transduced HepG2 cells to screen susceptibility -differences in PAH exposure. In conclusion, the CYP2E1 polymorphism may hardly induce susceptibility differences in PAH exposure monitoring with urinary naphthols.

• 한국산업보건학회지
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• 제26권1호
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• pp.11-19
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• 2016

Objectives: Exposure to volatile organic compounds such as trichloroethylene(TCE) and perchloroethylene(PCE), along with Agent Orange, that were issued around Camp Carroll US Army Base situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do Province, Korea. The main objective of this study was to assess the exposure to TCE and PCE of residents of the area surrounding Camp Carroll. Methods: The TCE, PCE and trichloroethanol(TCEOH) concentrations in blood and trichlroroacetic acid(TCA) and TCEOH concentrations in urine were measured and analyzed in a total of 1,033 residents around Camp Carroll. TCA and TCEOH are metabolites of TCE and PCE, respectively. The information on demographic characteristics and exposure variables in relation to underground water were obtained through a questionnaire completed by the subjects. Results: TCE, PCE and TCEOH concentrations were not detected in blood. Detection rates of TCA and TECOH concentrations in urine were 98.5% and 36.6%, respectively. Creatinine-corrected average TCA and TCEOH concentrations were $12.23{\pm}23.81{\mu}g/g$ and $0.66{\pm}4.31{\mu}g/g$, respectively. A significant difference was not shown between the drinking group and no drinking group for underground water, which was assumed as a potential route of exposure to TCE and PCE through the consumption of ground water. However, females drinking ground water showed a significantly higher mean level of TCA in urine than did males. There was no significant difference according to drinking ground water as a potential source of exposure to TCE and PCE in residents around Camp Carroll. Conclusions: Considering the statistical analysis of factors affecting exposure to TCE and PCE in ground water along with previous reports, TCA in urine as exposure to TCE and PCE might not be appropriate because it is found in chlorinated drinking water. Therefore, TCA concentration in urine may be the result of drinking of chlorinated water.

• 한국산업보건학회지
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• 제22권2호
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• pp.100-106
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• 2012

Objectives: Diazinon is an insecticide which acts as a contact stomach and respiratory poison, and used throughout the world to control a wide range of sucking and chewing insects and mites on a range of crops. In this study, the airborne diazinon levels were measured for farmers, pest control operaters, landscapers, and agricultural chemicals sellers, and an assessment of the health risk to the workers was presented. The exposure scenario was based on the route of inhalation and skin absorption. The "OSHA Method No. 62" was used to sample and measure the airborne diazinon levels. The skin wipe method was applied to measure the level of the diazinone exposure through the skin. For the determination of exposure scenario, the exposure factors were surveyed for the daily average inhalation rate and the exposure period and frequency and time of diazinone as well as the body weight and lifetime of the workers. The median values of exposure frequency and exposure time were selected after evaluating the validity of those. Methods: The highest level of the diazinon exposure in the air was $107.21ug/m^3$ in farmers, followed by $93.53ug/m^3$ in landscapers, at $31.40ug/m^3$ in pest control operators, and $1.04ug/m^3$ in agricultural chemical seller. The amount of skin absorption was the highest in farmers at 63.39 ug/day, followed by landscapers at 10.47 ng/day, pest control operaters at 4.26 ng/day, and agricultural chemicals sellers at 0.34 ng/day. The hazardous indices calculated using toxicological reference value were 2.79 for pest control operaters, 0.41 for landscapers, 0.07 for agricultural chemicals sellers, and 0.06 for farmers. Conclusions: While the farmers were exposed to the high levels of diazinon through the air and skin, the pest control operaters, landscapers and agricultural chemicals sellers have more the diazinon hazards than the farmer based on the risk assessment in this study.

• 한국해양바이오학회지
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• 제8권1호
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• pp.10-17
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• 2016

A wide-spread contamination of persistent organic pollutants (POPs) such as dioxins, PCBs, PBDEs in the aquatic ecosystem has generated a great concern over the potential risk for these substances to impact marine biotas and food web. Since a major exposure route of these substances to the humans is through the consumption of food including fish and marine byproducts, the consumption of contaminated products has been a great public health concern. Exposure to POPs has been associated with a wide spectrum of adverse effects including reproductive, developmental, immunologic, carcinogenic, and neurotoxic effects. This review covers the background information of key POPs substances and the recent development of toxicity studies including the mode of action. Because neurotoxic effects of some POPs have been observed in humans at low concentrations, polychlorinated biphenyl (PCB), a representative chemical of POPs, is focused to discuss the possible mode(s) of action for the neurotoxic effects. This review provides the updates of toxicity studies on POPs and paves ways to discuss a possible implication of contaminated marine biota over the human health among the marine biotechnology researchers.

• Journal of Astronomy and Space Sciences
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• 제37권4호
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• pp.229-236
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• 2020

There has been increasing necessity of more precise prediction and measurements of aviation radiation in Korea. For our air crew and passengers' radiation safety, we develop our own radiation prediction model of KREAM. In this paper, we validate the KREAM model based on comparison with Liulin observations. During early three months of this year, we perform total 25 experiments to measure aviation radiation exposure using Liulin-6K in commercial flights. We found that KREAM's result is very well consistent with Liulin observation in general. NAIRAS shows mostly higher results than Liulin observation, while CARI-6M shows generally lower results than the observations. The percent error of KREAM compared with Liulin observation is 10.95%. In contrast, the error for NAIRAS is 43.38% and 22.03% for CARI-6M. We found that the increase of the altitude might cause sudden increase in radiation exposure, especially for the polar route. As more comprehensive and complete analysis is required to validate KREAM's reliability to use for the public service, we plan to expand these radiation measurements with Liulin and Tissue Equivalent Proportional Counter (TEPC) in the near future.

• 방사성폐기물학회지
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• 제21권2호
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• pp.255-269
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• 2023

Compared to operational wastes, nuclear power plant (NPP) decommissioning wastes are generated in larger quantities within a short time and include diverse types with a wider range of radiation characteristics. Currently used 200 L drums and IP-2 type transport containers are inefficient and restrictive in packaging and transporting decommissioning wastes. Therefore, new packaging and transport containers with greater size, loading weight, and shielding performance have been developed. When transporting radioactive materials, radiological safety should be assessed by reflecting parameters such as the type and quantity of the package, transport route, and transport environment. Thus far, safety evaluations of radioactive waste transport have mainly targeted operational wastes, that have less radioactivity and a smaller amount per transport than decommissioning wastes. Therefore, in this study, the possible radiation effects during the transport from NPP to disposal facilities were evaluated to reflect the characteristics of the newly developed containers and decommissioning wastes. According to the evaluation results, the exposure dose to transport workers, handling workers, and the public was lower than the domestic regulatory limit. In addition, all exposure dose results were confirmed, through sensitivity analysis, to satisfy the evaluation criteria even under circumstances when radioactive materials were released 100% from the container.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7555-7560
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• 2013

Background: Beedi rollers are exposed to unburnt tobacco dust through cutaneous and pharyngeal route and it is extremely harmful to the body since it is carcinogenic in nature and can cause cancer during long exposure. This indicates that occupational exposure to tobacco imposes considerable genotoxicity among beedi workers. Materials and Methods: In the present study, 27 beedi workers and age and sex matched controls were enrolled for clinical, cytogenetics and molecular analysis. Clinical features were recorded. The workers were in the age group of 28-67 years and were workers exposure from 8-60 years. Blood samples were collected from workers and control subjects and lymphocyte cultures were carried out by using standard technique, slides were prepared and 50 metaphases were scored for each sample to find the chromosomal abnormalities. For molecular analysis the genomic DNA was extracted from peripheral blood, to screen the variations in gene, the exon 1 of CYP1A1 gene was amplified by polymerase chain reaction (PCR) and then screened with Single Strand Conformation Polymorphism (SSCP) analysis. Results: A statistically significant increase was observed in the frequencies of chromosomal aberrations in exposed groups when compared to the respective controls and variations observed in Exon 1 of CYP1A1(Cytochrome P450, family 1, subfamily A, polypeptide 1) gene. Conclusions: This study shows that, the toxicants present in the beedi that enter into human body causes disturbance to normal state and behavior of the chromosomes which results in reshuffling of hereditary material causing chromosomal aberrations and genomic variations.

• 대한소아치과학회지
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• 제32권3호
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• pp.543-549
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• 2005

상악 견치는 가장 긴 치근을 가지며 저작기능과 함께 하악의 측방운동을 유도하고 심미적으로도 치열궁의 구각부위에 위치하여 교합관계의 조화와 대칭을 유지하는 등의 중요한 기능을 수행한다. 상악 견치는 발육기간이 가장 길며 형성되어 맹출하기까지 복잡한 경로를 갖기 때문에 다른 치아보다 매복의 빈도가 높다. 이러한 매복치를 치료하기 위해 임상의는 관찰을 하거나 외과적 노출과 교정적 견인, 자가치아이식, 발치 등 다양한 치료방법을 고려할 수 있다. 외과적 노출과 교정치료는 견치를 교합선상에 배치할 수 있기 때문에 가장 이상적인 접근으로 생각할 수 있다. 본 증례 보고는 구개측으로 매복된 상악 견치를 외과적 노출과 교정적 치아이동을 통해 기능적, 심미적으로 양호한 결과를 얻었다.

• Environmental Analysis Health and Toxicology
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• 제26권
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• pp.8.1-8.9
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• 2011

Objectives: This study assessed the health risks for children exposed to phthalate through several pathways including house dust, surface wipes and hand wipes in child facilities and indoor playgrounds. Methods: The indoor samples were collected from various children's facilities (40 playrooms, 42 daycare centers, 44 kindergartens, and 42 indoor-playgrounds) in both summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). Hazard index (HI) was estimated for the non-carcinogens and the examined phthalates were diethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dibutyl-n-butyl phthalate (DnBP), and butylbenzyl phthalate (BBzP). The present study examined these four kinds of samples, i.e., indoor dust, surface wipes of product and hand wipes. Results: Among the phthalates, the detection rates of DEHP were 98% in dust samples, 100% in surface wipe samples, and 95% in hand wipe samples. In this study, phthalate levels obtained from floor dust, product surface and children's hand wipe samples were similar to or slightly less compared to previous studies. The $50^{th}$ and $95^{th}$ percentile value of child-sensitive materials did not exceed 1 (HI) for all subjects in all facilities. Conclusions: For DEHP, DnBP and BBzP their detection rates through multi-routes were high and their risk based on health risk assessment was also observed to be acceptable. This study suggested that ingestion and dermal exposure could be the most important pathway of phthalates besides digestion through food.