• Archives of Pharmacal Research
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• 제29권5호
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• pp.354-362
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• 2006

Dietary flavonoids have attracted a great deal of attention as agents for preventing estrogen-related diseases, such as postmenopausal symptoms, and for reducing the risk of estrogen-dependent cancer. Kaempferol is one of the most commonly found dietary phytoestrogen. The aim of this study was to investigate the estrogenic and/or antiestrogenic effect of kaempferol, which can confirm its potency as a preventive agent against estrogen-related diseases. Kaempferol has both estrogenic and antiestrogenic activity, which are biphasic response on estrogen receptor. The estrogenic activity of kaempferol induced via ER-mediated pathway depending on $E_2$ concentration $(\leq\;10^{-12}M)$. Kaempferol $(10^{-5}\;M)$ also caused antiproliferative effect on MCF-7 cell in the presence of $E_2\;(10^{-11}\;M)$ and restored to the addition of excess $E_2\;(10^{-7}\;M)$, which confirms that antiproliferation of kaempferol was induced via ER-dependent pathway. However, at $10^{-4}\;M$, concentration higher than the concentrations at which the estrogenic effects of kaempferol are detected $(10^{-5}\;M)$, kaempferol induced strong antiproliferative effect, but were unaffected by the addition of excess $E_2\;(10^{-7}\;M)$ indicating that kaempferol exerts antiproliferation via ER-independent pathway. In particular, kaempferol blocked the focus formation induced by $E_2$, which confirms that kaempferol might inhibit the malignant transformation caused by estrogens. Therefore, we suggested that kaempferol might regulate a suitable level of estrogenic activity in the body and is expected to have potential beneficial effects in preventing estrogen imbalance diseases (breast cancer, osteoporosis, cardiovascular disease and etc.).

• Environmental Analysis Health and Toxicology
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• 제18권3호
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• pp.219-224
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• 2003

1,4-Dioxane is used as a solvent for lacquers, paints, varnish removers, dye baths and printing compositions. And it is also used for detergent preparations, cosmetics, deodorants and fumigants. A method is described for the determination of 1,4-dioxane in water samples by GC/MS. The extraction recoveries were studied for some solvents and solvent volume ratio were investigated using r-butyl methyl ether (MTBE). Optimum condition was obtained by the liquid-liquid extraction using the 10 mL of MTBE for 10 mL of water. Method detection limit of 1,4-dioxane in the 20 mL of water samples was 0.05 ng/mL. It could be determined in the range of 0.24∼240 ng/mL in treated water, and in the range of 0.69∼81.9 ng/mL in raw water, respectively. Risk assessments with 1,4-dioxane exposure by drinking water ingestion were carried out. Based on the results of analysis, chronic daily intake of 1,4-dioxane was 2.22${\times}$10$\^$-4/ mg/kg/day and excess cancer risk was calcu-lated to be 2.44${\times}$10$\^$-6/.

• 환경영향평가
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• 제28권2호
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• pp.152-168
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• 2019

비소는 암 등의 질병 치료 및 생활용품 등의 원료로 사용되는 등 산업 활동 전반에 걸쳐 다양한 용도로 사용되어 온 원소이다. 그러나 토양 매립 폐기물 처리, 금속 제조 및 화석 연료의 사용 등으로 인해 환경 생태계를 오염시킬 수 있다. 특히 비소는 토양 및 미생물에 의한 자연적 요인과 산업활동과 같은 인위적 요인으로 발생 할 수 있어 환경매체 중에 광범위하게 존재하기 때문에 다른 원소에 비해 인체에 노출될 가능성이 크다. 따라서 본 연구는 기존의 단순농도 평가 및 단일 매체 중심의 오염원 관리의 단점을 극복하기 위해 다경로(흡입, 경구, 접촉 등)/다매체(대기, 수질, 토양 등) 거동 특성을 반영하여 인체 위해성 평가를 수행하였다. 결과적으로 노출경로별 비소가 인체에 가장 많이 노출되는 경로는 경구에 의한 기여도로 57~96 %를 차지했다. 상대적으로 다른 연령군에 비해 영유아에서 높은 노출량을 보였다. 이는 성인에 비해 체중이 적고 체표면적이 커서 유해물질에 더 많이 노출 될 수 있기 때문이다. 기존 연구에서 보고된 바와 같이, 비소는 경구 경로 중 먹는물의 기여도가 대부분의 연령층에서 주요 노출 경로를 보였다. 최종적으로 노출량 평가 결과에 근거하여 발암위해도 및 비발암위해도를 산정하였다. 산정결과 CTE 및 RME에 대한 발암위해도는 2.3E-05~6.7E-05의 범위로 모든 연령 군의 전체 시나리오에서 발암확률 1.0E-04을 초과하지 않았으므로, 발암위해를 무시할만한 수준으로 판단된다. 반면 RME에 대한 발암위해도는 6.4E-05~1.8E-04의 범위로써 영유아 및 미취학아동 군에서 1.3E-04~1.8E-04의 범위로 초과발암확률 1.0E-04을 초과하였다. CTE 및 RME에 대한 비발암위해도 결과는 위해지수가 각각 5.4E-02~1.9E-01, 1.5E-01~6.8E-01의 범위로 모든 연령 군의 전체 시나리오에서 위해지수 1을 초과하지 않았으므로, 비발암 위해성은 낮은 것으로 판단된다.

• 한국대기환경학회지
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• 제8권4호
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• pp.247-256
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• 1992

Airborne suspended particulates were collected at Shinchon by a high volume cascade impactor from Sep. 1990 to Aug. 1991. Organic matter was extracted from particulates and fractionated by liquid-liquid extraction and thin layer chromatography. Substances in the PAHs and nitroarenes'subfraction of neutral fraction were determined by capillary gas chromatography. Based on unit risk estimates by multi-stage model of benzo[a]pyrene and the results of exposure estimates, cancer risk was assessed. The annual average concentration of total suspended particulates was 201.77g/$m^3$. The percentage of fine particulates was 57.40. The concentration of total suspended particulates showed seasonal variations and was high in winter and spring. The average concentration of extractable organic matter was 8.12g/$m^3$. In all, 21 PAHs were identified and quantified. The annual concentration of fluoranthene was 2.38ng/$m^3$, and that was the highest value of all PAHs. A carcinogenic compound, benzo[a]pyrene, was at a concentration of 1.84ng/$m^3$. All the 10 nitroarenes were also identified and quantified. The major nitroarene in the Shinchon area was 2,7-dinitrofluorene. The annual concentration of 1-nitropyrene was 1.56ng/$m^3$. Concentrations of PAHs and nitroarenes were high in winter and low in summer. The life time excess risk estimates of benzo[a]pyrene was calculated as 0.96 persons/a million population in this experiment. In the rank of relative potenties, carcinogenic effects of the other PAHs were calculated as 0.004-0.108 persons/a million population.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.707-714
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• 2024

Different degrees of natural radioactivity found in quartz can have negative consequences on health. Quartz vein along the investigated Abu Ramad area, Egypt, had its natural radioactivity assessed. The HPGe spectrometer was used to determine the role played by the radionuclides ²³⁸U, ²³²Th, and ⁴⁰K in the gamma radiation that was emitted, and the results showed that these concentrations are 484.64 ± 288.4, 36.8 ± 13.1 and 772.2 ± 134.6 Bq kg^-1 were higher than the corresponding reported global limits of 33, 45, and 412 Bq kg^-1 for each radionuclide (²³⁸U, ²³²Th, and ⁴⁰K). Among the radiological hazard parameters, the excess lifetime cancer risk (ELCR) is estimated and it's mean value of ELCR (1.2) is higher than the permissible limit of 0.00029. The relationship between the radionuclides and the associated radiological hazard characteristics was investigated based on multivariate statistical methods including Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). According to statistical research, the radioactive risk of quartz is primarily caused by the ²³⁸U, ²³²Thand ⁴⁰K. Finally, applying quartz to building materials would pose a significant risk to the public.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권3호
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• pp.37-49
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• 2021

There is domestic Soil Contamination Warning Standard (SCWS) as remediation standard concentration of contaminated soils. No risk should be observed at soil concentration less than SCWS. Therefore, SCWS was evaluated to confirm the risk assessment. Background Concentration of Soil (BGC) and target remediation concentration were also assessed. The results show that Excess Cancer Risk (ECR) of SCWS was the highest in the groundwater intake pathway (Adult: 6.27E-04, Child: 2.81E-04). Total Cancer Risk (TCR) was 7.76E-04 and 4.30E-04 for adult and child, exceeding reference value (10^-6). Hazard Quotient (Non-Carcinogenic Risk, HQ) was the highest in the indoor air inhalation pathway (Adult: 3.64E+03, Child: 8.74E+02). Hazard Index (Total Non-Carcinogenic Risk, HI) exceeded reference value 1. ECR of the BGC was the highest in the groundwater intake pathway (Adult: 1.71E-04, Child: 7.67E-05). TCR was 2.12E-04 for adults and 1.17E-04 for children, exceeding the reference value (10^-6). HQ was the highest in groundwater intake pathway (Adult: 4.10E-01, Child: 1.84E-01). HI was lower than reference value 1 (Adult: 4.78E-01, Child: 2.50E-01). The heavy metal affecting ECR was Arsenic (As). The remediation-concentration of As was 7.14 mg/kg which is higher than BGC (6.83 mg/kg). TCR of As should be less than reference value (10^-6), but it was higher for all of SCWS, BGC and target remediation concentration. Therefore, it is suggested that risk assessment factors should be re-evaluated to fit domestic environmental settings and SCWS should be induced to satisfy the risk assessment.

• 대한방사선기술학회지:방사선기술과학
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• 제36권3호
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• pp.237-244
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• 2013

본 연구의 목적은 유방암 치료에 사용되는 다양한 첨단방사선치료법을 선량비교인자들을 이용하여 비교분석하고 이 결과를 이용하여 환자에 가장 적합한 치료방법을 찾기 위함이다. 인체밀도와 유사하게 제작된 모형팬텀을 이용하여 시뮬레이션을 진행하였고 Eclipse v10 소프트웨어를 이용하여 3차원 입체조형치료, 세기 변조 방사선치료, 입체세기조절회전 방사선치료 세 가지 치료계획을 수립하였다. 각 치료계획을 평가하기 위하여 균일지수, 순응도, 장기등가선량(OED), 초과절대위험률(EAR) 등을 이용하였다. 균일지수 값은 3차원 입체조형치료, 세기 변조 방사선치료, 입체세기조절회전 방사선치료에서 16.89, 11.21, 9.55, 순응도는 0.59, 0.61, 0.83 으로 계산되었다. 사용된 3가지 치료법의 평균선량은 왼쪽 폐 0.01 ~ 2.02 Gy, 오른쪽 폐 0.36 ~ 5.01 Gy, 간 0.25 ~ 2.49 Gy, 심장 0.14 ~ 6.92 Gy, 식도 0.03 ~ 2.02 Gy, 척수 0.01 ~ 1.06 Gy, 왼쪽 가슴 0.25 ~ 6.08 Gy, 기관 0.08 ~ 0.59 Gy, 위 0.01 ~ 1.34 Gy 의 범위로 나타났다. 장기등가선량(OED)와 초과절대위험률(EAR)은 모든 장기에서 세기 변조 방사선치료와 입체세기조절회전 방사선치료방법이 3차원 입체조형치료 보다 높게 나타났다. 이 연구의 결과로서, 우리는 선량분포지수(균일지수, 순응도)는 세기 변조 방사선치료, 입체세기조절회전 방사선치료가 3차원 입체조형치료 보다 좋을 수 있지만 주변 정상장기에 들어가는 선량은 3차원 입체조형치료보다 높다는 것을 확인할 수 있었다.

• Environmental Analysis Health and Toxicology
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• 제10권1_2호
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• pp.1-14
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• 1995

The purpose of this research is to assess the health risk of pollutants in drinking water and recommend the guidelines and management plans for maintaining good quality of drinking water. This study has been funded as a national project for three years from 1992 to 1995. This study(the second year, 1993-1994) was conducted to monitor 32 species of carcinogenic chemicals such as volatile organic compounds(VOCs), polynuclear aromatic hydrocarbons(PAHs), pesticides and heavy metals of drinking water at some area in six cities of Korea, and evaluate health risk due to these chemicals through four main steps of risk assessment in drinking water. In hazard identification, 32 species of carcinogenic chemicals were identified by the US EPA classification system. In the step of exposure assessment, sampling of raw, treated and tap water from the public water supply system had been conducted from 1993 to 1994, and 32 chemicals were analyzed. In dose-response assessment, cancer potencies, unit risk estimates and virtually safe doses of carcinogens were obtained by TOX-RISK (Version 3.1). In risk characterization of detected chemicals, health risk due to carcinogens such as vinyl chloride, carbon tetrachloride, dichloromethane, 1, 2-dichloromethane, chloroform, benzene and arsenic of tap water in several cities exceeded 10$^{-5}$ level. We suggest that non-regulated chemicals which exceed 10$^{-5}$ excess cancer risk level, such as vinyl chloride, carbon tetrachloride and 1, 2-dichloroethane, should be monitored periodically and be regulated by the Drinking Water Management Act, and database for exposure parameter of our own situation should be established.

• Asian Journal of Atmospheric Environment
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• 제6권3호
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• pp.206-221
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• 2012

Hazardous chemicals can be released from artificial turf used in some school playgrounds. To distinguish between Health risk assessment (HRA) exposure scenarios for this study, the ratio of elementary, middle and high schools was considered before final selection. Considering exposure pathways (inhalational, oral and dermal), media and materials were examined, targeting hazardous chemicals released from artificial turf playground-related products. Upon evaluation, the quantity of infill chips was shown to exceed the domestic product content standard (90 mg/kg) at eight (16%) out of 50 schools. PAHs were shown to exceed standards (10 mg/kg) at two (4%) out of the 50 schools. The excess cancer risk (ECR) of carcinogens was shown to be $1{\times}10^{-6}$ in most users for the worst exposure scenario. In children with pica, who represented the most extreme exposure group, the ECR was expected to be as high as $1{\times}10^{-4}$, showing the low risk level of carcinogens. The hazard index (HI) for individual chemicals was shown to be low, at around 0.1 or less, except for children with pica, according to the mean exposure scenario of artificial turf playground exposure. However, the HI was shown to exceed 1.0 in children with pica. Therefore, no direct health risk was found in using artificial turf playgrounds and urethane flooring tracks for the mean exposure scenario, except in children with pica.

• Environmental Analysis Health and Toxicology
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• 제23권1호
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• pp.53-62
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• 2008

In the present study, the concentration levels of polychlorinated biphenyls (or PCBs) in the environments in Korea are estimated based on some measured data in Korea, in comparison with the data from the other countries. Even though PCBs were banned as electrical fluids in 1970s in Korea, PCBs are still detected in the environment. PCBs levels in Korea are greatly lower than those in other countries, which are gradually decreased as well. However, the measured data are not sufficient in both numbers and quality, to estimate the average PCBs levels in Korea. The regulation limit on polychlorinated biphenyls (or PCBs) is 2mg/kg (ppm), which is too low compared to 50 ppm of many other countries including U.S. With this strict regulation, there are many problems expected, for example, in the analysis of PCBs in the transformers using in the field as well as the safe treatment of PCBs. The risk assessment on the PCBs in the environment is surely necessary prior to the change in the limit. Also the PCBs concentration monitoring in the environmental media (i.e. air, water, soil and sediment) and exposure assessment will be essential for the accurate risk assessment. If the PCB-waste guideline maintain as 2 ppm after 10 years, the excess cancer risk of PCBs exposure by ambient air, drinking water and soil was $10^{-8}$. But if the guideline mitigate as 50 ppm after 10 years, the cancer risk was increased by $10^{-7}$. The ecological risk quotient by regulation change was not exceed '1'.