• 제목/요약/키워드: cumulative exposure

검색결과 199건 처리시간 0.03초

한국인의 유해물질 식이 노출량 평가를 위한 대표식품 선정과 mapping (Selection of Representative Foods and 'Best-fit' Mapping of Other Foods for Estimation of a Comprehensive Exposure to Food Contaminants in a Korean Total Diet Study)

  • 고은미;신혜형;연미영;남은정;이윤나;김도희;이지연;김미혜;박성국;최훈;김초일
    • 한국식품과학회지
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    • 제43권6호
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    • pp.773-782
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    • 2011
  • 한국형 TDS에 필요한 차별화된 포괄적인 식품목록을 도출하기 위해, 가장 최근에 실시된 2009년 TDS에서 사용된 것과 동일한 식품섭취량 자료를 사용하여 대표식품 선정기준을 확대 보완하고 그 결과를 비교하였다. 식품별 섭취량 누적비율 90%까지 확대, 섭취빈도 5% 이상으로 확대 및 추가 고려요인으로 지용성 오염물질을 위한 지방섭취량 누적비율 80%까지에 포함되는 식품을 고려하여 총 161종의 식품이 선정되었다. 도출된 대표 식품 목록은 우리 국민이 2007년에 섭취한 것으로 조사된 모든 식품군을 포함하고 있어 그 포괄성이 입증되었다. 다음 단계로, 한국인의 일상적인 식이를 대표할 수 있는 식품섭취량 자료를 확보하기 위해, 총 18,022명을 대상으로 실시된 2008년도와 2009년도 국민건강영양조사의 식품섭취량 자료를 통합하고 여기에 등장한 687종 식품을 이용하여, 상기 기술된 선정기준에 따라 165종 식품을 선정하여 기본목록을 작성하였다. 이들을 식품군별로 분류한 후 유사식품의 중복선정을 피하기 위해 매우 유사한 식품 30종에 대해 각 식품군 내에서 다소비 순위와 다빈도 순위를 비교하여 상대적으로 순위가 낮은 식품 15종을 제외시키고, 각 식품군에서 대표식품으로 선정되지 않은 식품에 대한 검토를 통해 식품 구성과 성상이 현저히 달라서 mapping이 어려운 식품 10종을 추가하여 160종이 대표식품으로 최종 선정되었다. TDS 분석대상으로 최종 선정된 160종의 식품목록은 식품섭취량의 90.93%, 에너지 섭취량의 91.36%, 지방섭취량의 89.05%를 포괄하는 것으로 나타났다. 예산과 연구기간의 제약으로 모든 식품이 분석될 수는 없으므로 분석되지 않은 식품을 가장 유사한 대표 식품의 유해물질 분석결과에 매칭하는 방법인 'best-fit' mapping 과정을 적용한다면 유해물질별 총 섭취량의 산출이 가능하게 될 것이다. 본 연구에서는 우리 국민의 식생활을 반영할 수 있는 대표성 있는 식품섭취량 자료를 확보하여 체계적인 방법으로 대표 식품을 선정하고, mapping을 통해 모든 식품을 포괄할 수 있는 방법을 제시함으로써 유해물질별 총 노출량을 평가할 수 있는 기반을 마련하였다.

위해성에 근거한 정화목표 산정 및 복원전략 수립 (Determination of Target Clean-up Level and Risk-Based Remediation Strategy)

  • 류혜림;한준경;남경필
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제12권1호
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    • pp.73-86
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    • 2007
  • 위해성에 근거한 복원 전략(risk-based remediation strategy, RBRS)은 위해성평가를 통하여 오염지역의 위해성 또는 오염원을 효율적으로 관리하기 위한 의사결정과정 중의 일부로서, 토양에 존재하는 독성물질이 인간이나 생태계와 같은 수용체로 전이되어 발현되는 독성을 감소시키는 것을 목적으로 한다. 토양오염에 대한 위해성평가는 토양에서 대기로 확산되어나가는 오염물질의 흡입, 토양에서 지하수로 용출된 오염물질의 섭취, 토양 자체의 섭취와 접촉 등에 의한 위해성평가를 포함하며, 오염물질의 특성뿐만 아니라 수리지질학적 자료, 토지이용용도, 수용체의 특성 등 현장의 특이적인 요소들을 충분히 고려해야 한다. 위해성에 근거한 복원전략은 위해성산정을 위한 현장조사로부터 시작하여, 구체화된 노출경로모델(conceptual site model, CSM)의 작성, 목표위해성 수준의 결정, 오염물질의 물리화학적 특성 및 독성학적 자료의 수집을 거쳐, 일반적이고 보수적인 조건 하에 가장 안전한 목표정화수준을 산정하는 Tier 1 평가와 보다 정확한 오염현장의 조사를 통하여 현장특수성을 반영하는 Tier 2 평가를 단계적으로 적용한다. 현장의 오염농도가 Tier 1으로 결정된 허용오염수준(risk-based screening level, RBSL)보다 높은 경우 Tier 2를 실시하여 현장의 특수성을 반영하는 목표정화수준(site-specific target level)을 산정하며, 이를 통하여 오염지역에 대한 과도한 정화처리나 비경제적인 복구사업 등을 피할 수 있다. 위해성에 근거한 복원전략은 이 밖에도 오염지역의 복원우선순위 결정, 토지이용용도에 따른 위해성 관리기준 수립 등 다양한 활용성을 가지지만, 여러 가지 전제조건들과 현장조사 시에 발생하는 현실적 한계 등으로 인하여 불확실성을 가진다. 이를 극복하기 위하여 정확한 CSM의 작성, 복합오염에 대한 고려, 오염물질의 이동과 거동에 영향을 미치는 환경매질의 특성과 모델 입력변수 등을 신중하게 검토해야 하며, 신뢰할 만한 현장조사기법과 독성검사기법의 확립, 국내실정에 맞는 토양 및 지하수 특성자료와 인체 노출인자 등에 대한 연구가 지속적으로 이루어져야 할 것이다.

방사선취급 병원근무자들의 염색체이상 및 자매염색분체교환 빈도 (Chromosome Aberrations and Sister Chromatid Exchanges of Hospital Workers Exposed to Radiation)

  • 차애리;김미선;황인경;이수일;조병만;김돈균
    • Journal of Preventive Medicine and Public Health
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    • 제31권4호
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    • pp.616-627
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    • 1998
  • In order to evaluate the cytogenetic hazard among hospital workers potentially exposed to low dose of radiation, the analysis of chromosome aberrations(CA) and sister chromatid exchanges(SCE) in lymphocytes were performed in 79 hospital workers and 79 non-exposed workers. The mean frequency of chromosomal exchange and deletion(respectively, $0.20\times10^{-2}/cell\;and\;0.39\times10^{-2}/cell$) in the exposed group were significantly higher than those$(0.07\times10^{-2}/cell\;and\;0.23\times10^{-2}/cell)$ in control group. The frequency of sister chromatid exchanges was 5.04/cell in the control vs. 6.57/cell in the exposed group. There were also significant differences in the mean frequencies of CA and SCE adjusted for age, sex, smoking, drinking between two groups. There were no evidence of significant increase of CA and SCE according to the department or duration of employment. But the frequency of cells having chromosome aberration was significantly higher in the exposed group than in the control group related to duration of employment. There was no dose-effect relationship between the cumulative doses and the frequency of CA and SCE. But in the case of last 1 yr cumulative dose, there were evidence of significant dose-dependant increase of chromosome type CA and percentage of cells with aberration. The result suggest that there is cytogenetic hazard in risk group like hospital workers handling low dose radiation. And the analysis CA and SCE are useful biological indicators for the exposure of low dose level of radiation.

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난대상록활엽수종 조림지 활착률과 영향인자 (The Characteristics and Survival Rates of Evergreen Broad-Leaved Tree Plantations in Korea)

  • 박준형;정수영;이광수;이호상
    • 한국산림과학회지
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    • 제108권4호
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    • pp.513-521
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    • 2019
  • 본 연구는 전국 난대상록활엽수종의 조림지에 대한 생육환경 및 입지환경 특성과 활착률간의 관계특성으로부터 조림적지 의사결정 기초자료를 제공하고자 하였다. 1997년부터 후박나무(Machilus thunbergii), 구실잣밤나무(Castanopsis sieboldii) 등 난대상록활엽수 10종의 신규 조림지 180ha의 148개 조사구에 대한 활착률을 모니터링 한 결과 평균 활착률은 67.0±26.9%이었다. 활착률 편차가 크게 나타난 원인은 조림 적지에 관한 실증적 현지 검증이 부족한 상황에서 다양한 입지를 대상으로 시험 조림이 이루어진 결과로 판단된다. 각 조사구별 11개 생육환경 및 입지환경 특성, 조림전후 강수 등의 정성적 설명요인과 활착률의 정량적 요인 간의 관계특성으로부터 수량화 이론 I에 따른 활착률에 대한 기여도를 분석한 결과, 조림지 상층임분 울폐도, 풍노출도, 조림 전 누적 강수량, 경사도 등의 순으로 높게 나타났다.

Inhalation of Bacterial Cellulose Nanofibrils Triggers an Inflammatory Response and Changes Lung Tissue Morphology of Mice

  • Silva-Carvalho, Ricardo;Silva, Joao P.;Ferreirinha, Pedro;Leitao, Alexandre F.;Andrade, Fabia K.;da Costa, Rui M. Gil;Cristelo, Cecilia;Rosa, Morsyleide F.;Vilanova, Manuel;Gama, F. Miguel
    • Toxicological Research
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    • 제35권1호
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    • pp.45-63
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    • 2019
  • In view of the growing industrial use of Bacterial cellulose (BC), and taking into account that it might become airborne and be inhaled after industrial processing, assessing its potential pulmonary toxic effects assumes high relevance. In this work, the murine model was used to assess the effects of exposure to respirable BC nanofibrils (nBC), obtained by disintegration of BC produced by Komagataeibacter hansenii. Murine bone marrow-derived macrophages ($BMM{\Phi}$) were treated with different doses of nBC (0.02 and 0.2 mg/mL, respectively 1 and $10{\mu}g$ of fibrils) in absence or presence of 0.2% Carboxymethyl Cellulose (nBCMC). Furthermore, mice were instilled intratracheally with nBC or nBCMC at different concentrations and at different time-points and analyzed up to 6 months after treatments. Microcrystaline $Avicel-plus^{(R)}$ CM 2159, a plant-derived cellulose, was used for comparison. Markers of cellular damage (lactate dehydrogenase release and total protein) and oxidative stress (hydrogen peroxidase, reduced glutathione, lipid peroxidation and glutathione peroxidase activity) as well presence of inflammatory cells were evaluated in brochoalveolar lavage (BAL) fluids. Histological analysis of lungs, heart and liver tissues was also performed. BAL analysis showed that exposure to nBCMC or CMC did not induce major alterations in the assessed markers of cell damage, oxidative stress or inflammatory cell numbers in BAL fluid over time, even following cumulative treatments. $Avicel-plus^{(R)}$ CM 2159 significantly increased LDH release, detected 3 months after 4 weekly administrations. However, histological results revealed a chronic inflammatory response and tissue alterations, being hypertrophy of pulmonary arteries (observed 3 months after nBCMC treatment) of particular concern. These histological alterations remained after 6 months in animals treated with nBC, possibly due to foreign body reaction and the organism's inability to remove the fibers. Overall, despite being a safe and biocompatible biomaterial, BC-derived nanofibrils inhalation may lead to lung pathology and pose significant health risks.

관동화전탕액(款冬花煎湯液)이 기관지평골근(氣管支平滑筋)에 미치는 영향(影響) (FARFARAE FLOS INHIBITS HISTAMINE-INDUCED CONTRACTILE RESPONSES OF AIRWAY SMOOTH MUSCLE)

  • 한종현;강성용;유광석;진상식;하경화;이경자
    • 대한한방내과학회지
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    • 제17권1호
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    • pp.210-217
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    • 1996
  • Farfarae Flos, a traditional herb medicine, has been used in Korea and China for many centuries as a treatment for respiratory disease. The purpose of the present study was to determine the effect of Farfarae Flos on histamine-induced tracheal smooth muscle contraction in rats. Guinea pigs(500g, female) were killed by CO2 exposure and a segment (8-10mm) of the thoracic trachea from each guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine which evoked 50% of maximal response (ED50) was obtained from cumulative dose response curves for histamine (10-7-10-4M). Contractions evoked by histamine(ED50) were inhibited significantly by Farfarae Flos. The mean percent inhibition was 8.7% after 1.5mg/ml Farfarae Flos, and 33.5% (p<0.05) after 5.0mg/ml Farfarae Flos. Propranolol (10-7M) slightly but significantly attenuated the inhibitory effects of Farfarae Flos. Following treatment with propranolol, the mean percent inhibition caused by 5.0mg/ml Farfarae Flos. Indomethacin and methylene blue (10-7M) did not significantly alter the inhibitory effect of Farfarae Flos. These results indicate that Farfarae Flos can relax histamine-induced contraction of guinea pig tracheal smooth muscle, and that this inhibition involves, in part, symphathetic nerve system.

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더위지기가 기관지평활근에 미치는 영향 (Effects of Artemisia iwayomogi on the Airway Smooth Muscle)

  • 박진영;심진찬;김호근;선성규;진상식;김종천;한종현
    • 동의생리병리학회지
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    • 제16권2호
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    • pp.322-326
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    • 2002
  • Artemisia iwayomogi has been used in Korea for many centuries as a treatment for anemia. The effect of Artemisia iwayomogi on tracheal smooth muscle is not known. The purpose of the present study is to determine the effect of Artemisia iwayomogi on histamine induced tracheal smooth muscle contraction in guinea pigs. Guinea pigs(500g, male) were killed by CO₂ exposure and a segment (8-10mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted ‘in pairs’ in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine (His) which evoked 50% of maximal response (ED/sub 50/) was obtained from cumulative dose response curves for histamine (10/sup -7/~10/sup -4/M). Contractions evoked by His (ED/sub 50/) were inhibited significantly by Artemisia iwayomogi. In guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 31.9% (p<0.05) after 100㎕/㎖ Artemisia iwayomogi. L-NNA slightly but significantly attenuated the inhibitory effects of Artemisia iwayomogi. Following treatment with L-NNA, the mean percent inhibition caused by 100㎕/㎖ Artemisia iwayomogi fell to 44.6% in guinea pig induced by histamine contraction. Propranolol, indomethacin and methylene blue did not significantly alter the inhibitory effect of Artemisia iwayomogi. These results indicate that Artemisia iwayomogi can relax histamine induced contraction of guinea pig, and that this inhibition related to nitric oxide formation.

Antioxidant Effect of Captopril and Enalapril on Reactive Oxygen Species-Induced Endothelial Dysfunction in the Rabbit Abdominal Aorta

  • Kim, Ji Hoon;Kim, Hyuck;Kim, Young Hak;Chung, Won-Sang;Suh, Jung Kook;Kim, Sung Jin
    • Journal of Chest Surgery
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    • 제46권1호
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    • pp.14-21
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    • 2013
  • Background: Reactive oxygen species (ROS) are known to be related to cardiovascular diseases. Many studies have demonstrated that angiotensin-converting enzyme inhibitors have beneficial effects against ROS. We investigated the antioxidant effect of captopril and enalapril in nitric oxide mediated vascular endothelium-dependent relaxations. Materials and Methods: Isolated rabbit abdominal aorta ring segments were exposed to ROS by electrolysis of the organ bath medium (Krebs-Henseleit solution) after pretreatment with various concentrations (range, $10^{-5}$ to $3{\times}10^{-4}$ M) of captopril and enalapril. Before and after electrolysis, the endothelial function was measured by preconstricting the vessels with norepinephrine ($10^{-6}$ M) followed by the cumulative addition of acetylcholine (range, $3{\times}10^{-8}$ to $10^{-6}$ M). The relevance of the superoxide anion and hydrogen peroxide scavenging effect of captopril and enalapril was investigated using additional pretreatments of diethyldithiocarbamate (DETCA, 0.5 mM), an inhibitor of Cu/Zn superoxide dismutase, and 3-amino-1,2,4-triazole (3AT, 50 mM), an inhibitor of catalase. Results: Both captopril and enalapril preserved vascular endothelium-dependent relaxation after exposure to ROS in a dose-dependent manner (p<0.0001). Pretreatment with DETCA attenuated the antioxidant effect of captopril and enalapril (p<0.0001), but pretreatment with 3AT did not have an effect. Conclusion: Both captopril and enalapril protect endothelium against ROS in a dose-dependent fashion in isolated rabbit abdominal aortas. This protective effect is related to superoxide anion scavenging.

Mobile phone use and risk of glioma: a case-control study in Korea for 2002-2007

  • Yoon, Songyi;Choi, Jae-Wook;Lee, Eunil;Ahn, Hyongjin;Choi, Hyong Doo;Kim, Nam
    • Environmental Analysis Health and Toxicology
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    • 제30권
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    • pp.15.1-15.11
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    • 2015
  • Objectives There has been a growing concern about the possible carcinogenic effects of the electromagnetic radiofrequency fields emitted from mobile phones. The purpose of this study was to investigate the association between mobile phone use and the development of gliomas in Korea. Methods Our study methods were based on the International Interphone study that aimed to evaluate possible adverse effects of mobile phone use. This study included 285 histologically-confirmed Korean patients 15 to 69 years of age, with gliomas diagnosed between 2002 and 2007 in 9 hospitals. The 285 individually matched controls were healthy individuals that had their medical check-up in the same hospitals. Unconditional logistic regression was used to calculate the adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for use of mobile phones. Results For the entire group, no significant relationship was investigated between gliomas and regular use of mobile phones, types of mobile phones, lifetime years of use, monthly service fee, and the other exposure indices. Analyses restricted to self-respondents showed similar results. For ipsilateral users, whose the body side for usual mobile phone use match the location of glioma, the aORs (95% CIs) for lifetime years of use and cumulative hours of use were 1.25 (0.55 to 2.88) and 1.77 (0.32 to 1.84), respectively. However, the contralateral users showed slightly lower risk than ipsilateral users. Conclusions Our results do not support the hypothesis that the use of mobile phones increases the risk of glioma; however, we found a non-significant increase in risk among ipsilateral users. These findings suggest further evaluation for glioma risk among longterm mobile phone users.

Habitual Tea Consumption Reduces Prostate Cancer Risk in Vietnamese Men: a Case-Control Study

  • Hoang, Van Dong;Lee, Andy H;Pham, Ngoc Minh;Xu, Dan;Binns, Colin W
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권11호
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    • pp.4939-4944
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    • 2016
  • Background: An upward trend has been noted for the incidence of prostate cancer (PCa) in Vietnam, but information is limited on modifiable factors associated with this form of cancer. This case-control study was conducted to ascertain any relationship between habitual tea consumption and PCa risk. Materials and Methods: Two hundred and fifty-three incident patients with histologically confirmed PCa and 419 (340 community-based and 79 hospital-based) controls, matched by age, were recruited in Ho Chi Minh City during 2013-2015. Information on frequency, quantity and duration of tea consumption, together with demographics, habitual diet and lifestyle characteristics, was obtained by direct interviews using a validated questionnaire. Logistic regression analyses were performed to assess associations between tea consumption variables and PCa risk. Results: The control subjects reported higher tea consumption levels in terms of cumulative exposure, frequency and quantity of tea drank than the PCa patients. After accounting for confounding factors, increasing tea consumption was found to be associated with reduced risk of PCa. The adjusted odds ratios (95% confidence intervals) were 0.52 (95% CI 0.35-0.79) and 0.30 (95% CI 0.18-0.48) for participants drinking 100-500 ml/day and > 500 ml/day, respectively, relative to those drinking < 100 ml/day. Significant inverse dose-response relationships were also observed for years of drinking and number of cups consumed daily (P <0.01). Conclusion: Habitual tea consumption is associated with a reduced risk of PCa in Vietnamese men.