• 한국학교ㆍ지역보건교육학회지
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• 제22권4호
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• pp.49-60
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• 2021

Objectives: Laboratories have various latent physical, chemical, biological, and ergonomical factors according to the diversification and fusion of research and development activities. This study aims to investigate the chemical exposure concentrations of college laboratories and evaluate their health risks, and use them as basic data to promote the health of college students. Methods: The sampling and analysis of harmful chemicals in the air in laboratories were performed using Method 1500 of the U.S. National Institute for Occupational Safety and Health (NIOSH)의 Method 1500. The harmful chemicals in the laboratories were divided into carcinogenic and non-carcinogenic chemicals. Risk assessment was performed using the cancer risk (CR) for carcinogenic chemicals and using the hazard index (HI) for non-carcinogenic chemicals. Results: The harmful chemicals in college laboratories consisted of acetone, diethyl ether, methylene chloride, n-hexane, ethyl acetate, chloroform, tetrahydrofuran, toluene, and xylenes. They showed the highest concentrations in laboratories A (acetone 0.001~2.34ppm), B (chloroform 0.95~6.35ppm), C (diethyl ether 0.08~8.68ppm), and D (acetone 0.07~14.96ppm). The risk assessment result for non-carcinogenic chemicals showed that the HI of methylene chloride was 2.052 for men and 2.333 for women, the HI of N-hexane was 4.442 for men and 5.05 for women. Thus, the HI values were higher than 1. The risk of carcinogenic chemicals is determined by an excess cancer risk (ECR) value of 1.0×10^-5, which means that one in 100,000 people has a cancer risk. The ECRs of chloroform exceeded 1.0×10^-5 for both men and women, indicating the possibility of cancer risk. Conclusion: College laboratories showed the possibility of non-carcinogenic health risks for methylene chloride, n-hexane, tetrahydrofuran (THF), toluene, and xylenes, and carcinogenic health risks for chloroform, methylene chloride. However, this study used the maximum values of measurements to determine the worst case, and assumed that the subjects were exposed to the corresponding concentrations continuously for 8 hours per day for 300 days per year. In consideration of the nature of laboratory environment in which people are intermittently exposed, rather than continuously, to the chemicals, the results of this study has an element of overestimation.

• 한국환경과학회지
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• 제33권5호
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• pp.283-296
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• 2024

This study examined the distribution of airborne metals concentrations and conducted a risk assessment in PM-10 in Gwangju from 2014 to 2022. There were a total of six points, and the concentration of heavy metals at each point was highest in the order of Pyeong-dong(1.5472 ㎍/m³ ) > Nongseong-dong(1.2093 ㎍/m³ ) > Geonguk-dong(1.0100 ㎍/m³ ) > Duam-dong(0.9684 ㎍/m³ ) > Seo-dong(0.9515 ㎍/m³ ) > Nodae-dong(0.8321 ㎍/m³ ). In recent years, the concentration of heavy metals in the atmosphere has generally risen, accompanied by an increase in heavy metals in the soil. The average seasonal concentrations were in the following order: spring(1.4448 ㎍/m³ ) > winter(1.2939 ㎍/m³ ) > fall(0.8303 ㎍/m³ ) > summer (0.5928 ㎍/m³ ). The atmospheric heavy metals most correlated with PM-10 were Ca(0.69), Fe(0.62), Al(0.62) and Mg(0.60). Within the acceptable risk level (1.0E-06) set in this study, heavy metals in the atmosphere were found to have the most excess cancer risk, and the integrated non-cancer risk was as low as 1 or less.

• Nutrition Research and Practice
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• 제9권6호
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• pp.628-636
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• 2015

BACKGROUND/OBJECTIVES: Obesity is a risk factor of breast cancer in postmenopausal women. Estrogen deprivation has been suggested to cause alteration of lipid metabolism thereby creating a cellular microenvironment favoring tumor growth. The aim of this study is to investigate the effects of estrogen depletion in combination with excess energy supply on breast tumor development. MATERIALS/METHODS: Ovariectomized (OVX) or sham-operated C3H/HeN mice at 4 wks were provided with either a normal diet or a high-fat diet (HD) for 16 weeks. Breast tumors were induced by administration of 7,12-dimethylbenz(a)anthracene once a week for six consecutive weeks. RESULTS: Study results showed higher serum concentrations of free fatty acids and insulin in the OVX+HD group compared to other groups. The average tumor volume was significantly larger in OVX+HD animals than in other groups. Expressions of mammary tumor insulin receptor and mammalian target of rapamycin proteins as well as the ratio of pAKT/AKT were significantly increased, while pAMPK/AMPK was decreased in OVX+HD animals compared to the sham-operated groups. Higher relative expression of liver fatty acid synthase mRNA was observed in OVX+HD mice compared with other groups. CONCLUSIONS: These results suggest that excess energy supply affects the accelerated mammary tumor growth in estrogen deprived mice.

• 환경영향평가
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• 제29권4호
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• pp.286-297
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• 2020

본 연구에서는 국내 4개 도시(6개 지점)로부터 도로 노면 퇴적입자 내 PAHs의 농도 및 분포특성을 비교, 분석하고 오염 수준에 대한 초과 발암 위해도를 산정하여 인체 위해성 평가를 수행하였다. 지역별 오염농도를 바탕으로 흡입, 섭취, 피부 노출에 대한 노출경로를 설정하여 결정론적 위해성평가를 수행한 결과, 울산 지역의 경우 위해도 발암 기준 1×10^-6을 상회하는 결과가 나타났다. 또한 발암위해도가 있다고 판단되는 해당 지역에 대한 확률론적 위해성평가 결과, 확률적 평균값이 단일값을 활용한 결정론적 위해도 산정에서 도출되었던 발암위해도와 중앙값에 근접한 수준을 나타내었다. 민감도 분석 결과, 노출시간에 따른 기여도가 가장 크게 나타났다. 향후 기준치를 초과하는 발암 위해도를 나타내는 지역에 대한 위해도 관리는 물론 상세한 모니터링을 통한 추가 위해성 평가가 이루어져야 할 것으로 판단되며, 지역적 특성을 반영한 노출계수의 산정을 통해 인체 위해도 평가 결과 신뢰도를 높여야 할 것으로 사료된다.

• 한국환경보건학회지
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• 제36권1호
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• pp.14-19
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• 2010

Based on a nationwide survey of the consumption of oriental medicine by the Korean population, we estimated the potential risk from the inadvertent ingestion of heavy metals such as Pb, Hg, As, and Cd as a result such consumption. Compared to the provisional daily intake limit, heavy metal intake through oriental medicine resulted in hazard quotients of less than one. The upper $90^{th}$ percentile exposure estimates for each metal also showed insignificant risk. In relation to inorganic forms that are known carcinogens the excess cancer risk was less than $1{\times}10^7$. Based on the results of this study exposure to Pb, Hg, As, or Cd through oriental medicine intake appeared to be negligible and would not cause a significant impact on health.

• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.203-216
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• 1999

This paper describes a set of multi-pathway models for estimating health risk to lead. The models link concentrations of an environmental contaminant (lead) in air, water and food to human exposure through inhalation, ingestion, and dietary routes. Exposure is used as the foundation for predicting risk of health detriment within the population. The process of estimating exposure using often limited data and extrapolating to a large diverse population requires many assumption, inferences, and simplification. This paper is divided into four section. The first section provides lead contaminant levels on obtaining environmental concentration of air, tap water, and foods. The second section provides a discussion of exposure parameters and uncertainty associated predicting human health risk of contaminants. The third and fourth section illustrate lifetime average daily exposure (LADE) and excess cancer risk (ECR) based on exposure parameters. The relationship between concentration of lead in an environmental medium and human exposure is determined with pathway exposure factors (PEFs). The calculation of LADE and ECR is carried out using Monte-Carlo simulation with probability density function of exposure parameters. Examination of the result reveals that, for lead exposure, ingestion (food) is the dominant route of exposure rather than inhalation (air), and ingestion (tap eater).

• 한국환경보건학회지
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• 제47권2호
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• pp.155-165
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• 2021

Objectives: Acute exposure to high concentrations of chemicals can occur when a chemical accident takes place. As such exposure can cause ongoing environmental pollution, such as in the soil and groundwater, there is a need for a tool that can assess health effects in the long term. The purpose of this study was assessing the health risks of residents living near a chemical accident site due to long-term exposure while considering the temporal concentration changes of the toxic chemicals leaked during the accident until their extinction in the environment using a multimedia environmental dynamics model. Methods: A health risk assessment was conducted on three cases of formaldehyde chemical accidents. In this study, health risk assessment was performed using a multimedia environmental dynamics model that considers the behavior of the atmosphere, soil, and water. In addition, the extinction period of formaldehyde in the environment was regarded as extinction in the environment when the concentration in the air and soil fell below the background concentration prior to the accident. The subjects of health risk assessment were classified into four groups according to age: 0-9 years old, 10-18 years old, 19-64 years old, and over 65 years old. Carcinogenic risk assessment by respiratory exposure and non-carcinogenic risk assessment by soil intake were conducted as well. Results: In the assessment of carcinogenic risk due to respiratory exposure, the excess carcinogenic risk did not exceed 1.0×10-6 in all three chemical accidents, so there was no health effect due to the formaldehyde chemical accident. As a result of the evaluation of non-carcinogenic risk due to soil intake, none of the three chemical accidents had a risk index of 1, so there was no health effect. For all three chemical accidents, the excess cancer risk and hazard index were the highest in the age group 0-9. Next, 10-18 years old, 65 years old or older, and 19-64 years old showed the highest risk. Conclusion: This study considers environmental changes after a chemical accident occurs and until the substance disappears from the environment. It also conducts a health risk assessment by reflecting the characteristics of the long-term persistence and concentration change over time. It is thought that it is of significance as a health risk assessment study reflecting the exposure characteristics of the accident substance for an actual chemical accident.

• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4769-4775
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• 2015

Background: Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and thirdly leading cause of cancer-related death worldwide. The estimated risk of hepatocellular carcinoma is 15 to 20 times as high among persons infected with HCV as it is among those who are not infected, with most of the excess risk limited to those with advanced hepatic fibrosis or cirrhosis. Glypican3 (GPC3) plays a key role in relation to signaling with growth factors, regulating the proliferative activity of cancer cells. Glutamine synthetase (GS) catalyzes the synthesis of glutamine from glutamate and ammonia in the mammalian liver. GS was suggested as a specific marker for tracing cell lineage relationships during hepatocarcinogenesis. In normal liver, GS expression is seen in pericentral hepatocytes, but not by midzonal or periportal hepatocytes. In HCC, strong and diffuse GS expression in seen in tumor cells. Results: Glypican3 immunopositvity was highly specific and sensitive indicator for hepatocellular carcinoma as well as glutamine synthetase which was found to be a sensitive and specific indicator for development of hepatocellular carcinoma when compared to cirrhosis, liver cell dyspalsia and metastatic carcinomas. Statistical analysis revealed a significant association between GPC3 and GS with tumor size (P=0.003, p=0.006, respectively). Diffuse staining significantly associated with large tumor size while, focal and mixed staining was detected more with small tumor size. Studying the relation with tumor grade also revealed significant association between diffuse GPC3 and GS staining with high tumor grade. Diffuse staining was detected in 91.7% and 100% respectively of poorly differentiated specimens and only in 33.3% and 22.2% of well differentiated specimens. Conclusions: While using GPC3 and GS to screen for premalignant hepatic lesions remains controversial, our data suggest that GPC3 and GS may be a reliable diagnostic immunomarkers to distinguish HCC from benign hepatocellular lesions. However, negative immunostaining should not exclude the diagnosis of HCC.

• 보험의학회지
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• 제32권2호
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• pp.39-49
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• 2013

The textbook of insurance medicine is very bulky volume and it's revision time may be long. Nowadays medical knowledge and evidences are developing rapidly. It is necessary to revise current insurance risk of certain disease. Review of respiratory diseases in terms of insurance medicine may be valuable information for insurance doctors and life underwriters. Newly estimated mortality ratio and excess death rate of several respiratory diseases in this review are organizing pneumonia, 266%/44‰; multi-drug resistant tuberculosis, 1200%/110‰; idiopathic interstitial pneumonia, 869%/85‰; VATS lobectomy of stage I lung cancer, 550%/33‰; lymphangioleiomyomatosis 9826%/66‰; lung transplantation 2026%/92‰, respectively.

• Environmental Analysis Health and Toxicology
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• 제20권2호
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• pp.179-186
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• 2005

Particulate materials (PM) less than 10 ${\mu}m$ in diameter are of special interest in air pollution because they are respirable and responsible for the increasing mortality rate of lung cancer and cardiovascular diseases. These particles are often referred to as $PM_{10}$ and they are divided into a coarse fraction and a fine fraction which is also often referred to as $PM_{25}$. In this study, we monitored the TSP, $PM_{10},\;PM_{2.5}$ concentration of ambient air collected in northern part of Seoul in early spring and measured the concentration of heavy metals; Cr, Mn, Zn, As, Cd, and Pb. All the heavy metals were found in the collected particles and the concentrations were variable in the $PM_{10},\;and\;PM_{2.5}$ respectively. The detected concentration ranges were Cr: $ND\~2,889ng/m^3,\;Mn:2.4\~257.9ng/m^3,\;Zn:ND\~353.7ng/m^3,\; As:ND\~22.3ng/m^3,\;Cd:0.1\~2.9ng/m^3,\;and\;Pb:ND\~392.2ng/m^3$ in fine particles. Heavy metal toxicity of the particles were also tested in $H_9C_2$ cell line derived from rat cardiomyocytes. As for the results of health risk assessment calculated by unit risk of IRIS, heavy metals in ambient air of Seoul metropolitan area were found to be responsible for the increase of total excess cancer risk. Among them, chromium (hexavalent) was found to be the most risky in fine particles of ambient air collected in the northern part of Seoul in early spring.