• 제목/요약/키워드: Co-exposure

검색결과 1,004건 처리시간 0.037초

Development of Biosphere Assessment Modeling Strategy for Deep Geological Disposal in Generic Site of the Korean Peninsula

  • Do Hyun Kim;Wontak Lee;Dongki Kim;Jonghyun Kim;Joowan Park
    • 방사성폐기물학회지
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    • 제21권1호
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    • pp.149-164
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    • 2023
  • As part of the safety case development for generic disposal sites in Korea, it is necessary to develop generic assessment models using various geosphere-biosphere interfaces (GBIs) and potentially exposed groups (PEGs) that reflect the natural environmental characteristics and the lifestyles of people in Korea. In this study, a unique modeling strategy was developed to systematically construct and select Korean generic biosphere assessment models. The strategy includes three process steps (combination, screening, and experts' scoring) for the biosphere system conditions. First, various conditions, such as climate, topography, GBIs, and PEGs, were combined in the biosphere system. Second, the combined calculation cases were configured into interrelation matrices to screen out some calculation cases that were highly unlikely or less significant in terms of the exposure dose. Finally, the selected calculation cases were prioritized based on expert judgment by scoring the knowledge, probability, and importance. The results of this study can be implemented in the development of biosphere assessment models for Korean generic sites. It is believed that this systematic methodology for selecting the candidate calculation cases can contribute to increasing the confidence of future site-specific biosphere assessment models.

Livedo reticularis following administration of ChAdOx1 nCoV-19 vaccine (AZD1222): a report of two cases

  • Joong Ho Kim;Ji An Uh;Ho Sung Kim;Soo Kyung Lee;Myoung Shin Kim;Un Ha Lee
    • Clinical and Experimental Vaccine Research
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    • 제11권3호
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    • pp.298-301
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    • 2022
  • The cutaneous appearance of transient or persistent livedo reticularis is characterized by violaceous, mottled, ring-shaped interconnecting lesions that form a reticular or net-like pattern. It can occur physiologically in response to cold exposure, such as in cutis marmorata, but can also be induced by pathological conditions such as vascular obliterans or venodilation. We report two cases of livedo reticularis that occurred on the lower limbs of two patients post ChAdOx1 nCoV-19 vaccination. As the patients had no other likely causes of livedo reticularis, the reticular skin lesions were suspected to occur in association with the ChAdOx1 nCoV-19 vaccination. Livedo reticularis is an uncommon adverse reaction, with few cases being reported post ChAdOx1 nCoV-19 vaccination.

고압 이산화탄소에 의한 Leuconostoc sp.의 살균 효과 (Effect of High Pressure Carbon Dioxide on Inactivation of Leuconostoc sp.)

  • 홍석인;박완수;변유량
    • 한국식품과학회지
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    • 제29권6호
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    • pp.1202-1207
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    • 1997
  • 가열 살균을 대체하여 식품의 신선도를 유지하면서 효과적으로 미생물을 사멸시킬 수 있는 새로운 비가열 살균기술로서 고압 $CO_2$, 처리를 고찰하고자 하였다. 이를 위해 김치에서 분리한 Leuconostoc sp.를 대상 미생물로 가압 조절인자를 달리하여 이 균주에 미치는 고압 $CO_2$의 살균 효과를 검토하였다. 사용 압력과 온도, 처리시간이 증가할수록, 이에 반해 작업용량은 감소할수록 균체의 사멸율이 증가하였으며, $30^{\circ}C$, $60\;kg/cm^2$$CO_2$가압 조건에서 젖산균 배양액을 $10^{-3}$만큼 감균하는데 약 150분이 소요되었다. 실험 결과로부터 고압 $CO_2$에 의한 미생물 살균은 기본적으로 $CO_2$의 세포내 침투에 의해 좌우되며, 따라서 세포 내부로의 $CO_2$ 전달 과정이 전체적인 살균 효율을 결정짓는 가장 중요한 단계임을 확인할 수 있었다.

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연립 주택 화재시 유독가스 방출 특성과 Rats를 이용한 독성평가 (Toxicity Evaluation of Effluent Gases from a Residental Fire by Rats)

  • 김홍;강영구;김동현;정기창;이창섭;김운형
    • 한국화재소방학회논문지
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    • 제16권3호
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    • pp.12-15
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    • 2002
  • 화재에 의한 독성가스의 노출은 인간에게 있어서 화재시 생명에 아주 위험한 요소일 것이다. 다양한 화재에 의한 독성가스의 노출 중 본 논문에서는 경기도 안산시 재개발지구에서 한 연립주택을 이용하여 실재화재와 같은 조건으로 화재 시험을 하였다. 화재시 발생하는 가스 CO, $CO_2$, $O_2$, $SO_2$, NO 및 $NO_2$등을 측정하였으며, 발생하는 가스를 실험동물인 백서(S.D.)에 노출시켜 2분 간격으로 혈액을 체취 하였다. 독성 평가를 위하여 백서의 혈액과 혈청 중 Glucose, AST(GOT), ALT(GPT), CBC Count 및 CO(carboxy)-Hb를 분석하였다. 폭로되는 CO의 농도와 백서의 혈액중 CO-Hb 농도사이에 양-반응 관계(dose-response relationship)를 보였다.

고로슬래그 미분말 치환율에 따른 이산화탄소 양생 모르타르의 기초 물성 (Fundamental Characteristics of CO2-cured Mortar with Varied Rates of Blast Furnace Slag Fine Powder Substitution)

  • 류지수;장경수;나형원;형원길
    • 한국건축시공학회지
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    • 제24권1호
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    • pp.11-21
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    • 2024
  • 본 실험에서는 고로슬래그 미분말 치환율에 따른 이산화탄소 양생 모르타르의 기초 물성을 확인하였다. 실험 결과, 이산화탄소 양생은 CaCO3의 생성을 촉진하며 공극 감소와 조기 강도 발현에 영향을 준다. Ca(OH)2가 CaCO3보다 주된 강도 발현에 영향을 주며 고로슬래그 미분말 치환율이 높은 배합일수록 Ca(OH)2 생성이 감소한다. 하지만 Ca(OH)2가 소모된 이후에도 CaCO3를 통해 강도가 유지되며 이산화탄소 양생 이후 대기 중에 노출하여도 소요의 성능을 유지할 수 있을 것으로 전망된다. 고로슬래그 미분말 치환율이 50%를 초과할 경우 이산화탄소에 의한 성능 저하를 유발하므로 치환 비율을 조정할 필요가 있다.

Influence of Maternal Environmental Tobacco Smoke Exposure Assessed by Hair Nicotine Levels on Birth Weight

  • Lee, Jungun;Lee, Dong-Ryul;Lee, Do-Hoon;Paek, Yu-Jin;Lee, Won-Chul
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권7호
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    • pp.3029-3034
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    • 2015
  • Background: While the perinatal outcomes of active maternal smoking are well documented, results of the effects of environmental tobacco smoke (ETS) exposure during pregnancy are inconsistent. We aimed to examine the effect of ETS exposure, assessed by maternal hair nicotine levels at $35^{th}$ week of gestation, on birth weight and the risk of small for gestational age (SGA) and low birth weight (LBW). Materials and Methods: A total of 871 non-smoking healthy pregnant women were recruited by one Korean hospital between 1 October 2006 and 31 July 2007. Hair samples were collected and anthropometric questionnaires administered at $35^{th}$ week of gestation. The primary outcome was birth weight and secondary outcomes were the risk of babies being SGA and LBW. Results: Log-transformed hair nicotine concentrations were inversely related with birth weight after adjusting for confounding variables (${\beta}=-0.077$, p=0.037). After stratifying hair nicotine levels by tertiles (T1, low [0.0-0.28 ng/mg]; T2, medium [0.29-0.62 ng/mg]; and T3, high [0.63-5.99 ng/mg]), the mean birth weight in each groups were 3,342g (T1) 3,296g (T2) and 3,290 g (T3), respectively. However the difference between groups was not statistically significant by analysis of co-variance (ANCOVA) adjusting for covariates (p=0.062). In logistic regression analysis, the risk of SGA was higher in the T3 (OR=1.59, 95%CI 1.05-2.42) than in the reference group (T1), after controlling for confounding variables. The risk of low birth weight (<2,500g, LBW) was not significantly higher (OR=1.44, 95%CI 0.95-2.19), but the risk of babies being below 3,000g birth weight was increased in the T3 group (OR=1.53, 95%CI 1.00-2.36) compared with that in the T1 group. Conclusions: Maternal ETS exposure during pregnancy was inversely related with birth weight. The risk of SGA increased in the highest ETS exposure group compared with in the low exposure group. To prevent ETS exposure during pregnancy, more comprehensive tobacco control policies are needed.

OECD 대량생산화학물질 위해성평가 및 대책 (Risk Assessment in OECD High Production Volume Chemicals Program and its Countermeasure)

  • 김명진;배희경;최연기;김미경;구현주;송상환;최광수
    • 환경영향평가
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    • 제14권5호
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    • pp.347-353
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    • 2005
  • The risk assessment is the qualitative or quantitative evaluation of the risk posed to human health and the environment by the actual or potential presence or release of hazardous substances, pollutants or contaminants. The environmental impact assessment (EIA) is assessed by the environmental criteria, and risk assessment is assessed by the risk rate. Risk rate based on dose-response values may not be easy to apply on regulatory basis like EIA for uncertainty. Internationally there is an example of OECD program. Risk assessment of High Production Volume (HPV) Chemicals has started since the OECD Program with the 1990 Council Act on the Co-operative Investigation and Risk Reduction of Existing Chemicals. These HPV chemicals include all chemicals produced or imported at levels greater than 1,000 tonnes per year in at least one Member country or in the European Union region. The SIDS called the Screening Information Data Set is regarded as the minimum information needed to assess an HPV chemical to determine whether any further work should be carried out or not. All the data elements of SIDS including assessment for environment and health are prepared as three formats of the full SIDS Dossier, the SIDS Initial Assessment Report (SIAR), and the SIDS Initial Assessment Profile (SIAP) of an HPV chemical. In 1998 the global chemical industry through the International Council of Chemical Associations (ICCA) has joined to work with OECD. The OECD has assessed approximately 1,000 chemicals from 1991 through 2004 with ICCA. Till the February of 2005, 592 chemicals of those chemicals completed SIDS reports. Member countries have been targeted the goal of 1,000 new chemicals from 2005 to 2010 and Korea shared 36 chemicals from the 1,000 new chemicals. Currently Korea has completed SIDS reports of 7 chemicals among sponsored 24 chemicals. In conclusion SIDS project will be linked to national program for outputs application with more reliable production. Both the OECD and industry will carry out their commitment to complete assessments for more and the remaining chemicals assessment. The major outputs will contribute to cope with international chemical management.

유방촬영 시 갑상샘의 피폭선량 경감을 위한 Al Face Block 제작 및 유용성에 관한 연구 (The Usefulness of Al Face Block Fabrication for Reducing Exposure Dose of Thyroid Glands in Mammography)

  • 홍은애;이인자
    • 대한방사선기술학회지:방사선기술과학
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    • 제36권1호
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    • pp.11-17
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    • 2013
  • 최근 환자가 안심하고 진료를 받을 수 있도록 의료 환경의 변화에 따라 의료 피폭 저감화 대책이 국내, 국제적으로 추진되고 있다. 연구자는 유방촬영 시 보다 안전하게 검사를 받을 수 있도록 환자의 방사선 피폭에 대한 방어 및 안전 관리가 절실 하다고 생각되어 본 차폐체를 개발하고, 제작하게 되었다. 임상에서 사용 중인 유방촬영 장치로 SID 65 cm, 조건 28 kVp, 63 mAs, 측정기는 Victoreen 6000-529(Fluke Co.)를 이용하여 제작한 Face Block을 사용하여, 환자 30명을 대상으로 실제 갑상샘 위치에 Chamber를 놓고 CC, MLO를 촬영해 Face Block장착 전, 후 선량을 측정하였다. 그 결과 Face Block 장착 후 CC View에서 평균 65.9%의 선량이 감소되었고, MLO View에서는 평균 60.7%의 선량이 감소되었으며, 영상의 질에는 큰 변화가 없었다. 따라서 유방촬영 시 갑상샘의 피폭을 줄이고, 실용적이고, 유용한 실제 Face Block을 개발한 것에 큰 성과가 있었다고 생각되며, 유방촬영 시 환자들의 피폭에 관한 불안감을 해소시켜, 환자 만족도 증대와 함께 환자 피폭선량 경감에 크게 이바지 할 것으로 기대하며, 피폭선량을 줄일 수 있는 방안을 끊임없이 노력해야 할 것이다.

폴리에틸렌 미세플라스틱과 납의 복합노출에 따른 실험동물의 세포면역기능 조절 장애 평가 (Dysregulation of Cellular Immune Functions on Gastric Administration to Mixtures of Polyethlene Microplastics and Metallic Lead in Mice)

  • 이경우;김창열
    • 한국환경보건학회지
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    • 제49권1호
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    • pp.22-29
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    • 2023
  • Background: The existing research results on the combined toxicity of these pollutants using mammals, such as rodents, are insufficient, especially in relation to changes in the immune system. Objectives: This study aims at evaluating the cellular immune response to PE-MPs solely or when combined with Pb, which possess excellent adsorption capacity with PE-MPs and is commonly co-exposed in our daily lives. Methods: The study investigated the cellular immune function of 9-week ICR mice with 28 days exposure to PE-MPs (2 mg/mouse/day) and Pb (0.1 mM in distilled water) individually and in combination. PE-MPs were administered via gastric intubation while the lead intake was conducted via the oral drinking water route. Cellular immunity was evaluated by analyzing the production for TH1 cytokines namely, TNF-α and IFN-𝛾 and TH2 cytokines, IL-4 and IL-6 in culture supernatants from polyclonally activated splenic mononuclear cells ex vivo. Results: Both the PE-MPs only and the PE-MPs+Pb exposure group revealed an increased TH1 response with elevated TNF-α and IFN-𝛾 levels and downregulated TH2 response with low IL-4, and IL-6 production levels compared to the control group. Furthermore, an increased IFN-𝛾/IL-4 ratio was found in the PE-MPs only and PE-MPs+Pb exposure groups, which indicated the skewedness to TH1 response. Meanwhile, reduced blood hemoglobin levels and increased levels of IL-4, the dominant TH2 cytokine in the Pb-only exposure group, were observed. Conclusions: Our current findings on the predominance of TH1 immune response in the PE-MPs and PE-MPs+Pb groups suggest that PE-MPs could be responsible for the predominant induction of the cellular immune changes. This finding could be used as an important landmark in research related to TH1 predominance, such as autoimmune diseases. It suggests that additional research on immune modulation using longer exposure durations or the same exposure route is required to elucidate stronger findings.

저준위 방사선 노출의 암 유발에 관한 국내 원전종사자 코호트 연구 (A Cohort Study on Cancer Risk by Low-Dose Radiation Exposure among Radiation Workers of Nuclear Power Plants in Korea)

  • 임영기;유근영
    • Journal of Radiation Protection and Research
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    • 제31권2호
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    • pp.53-63
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    • 2006
  • 원전 종사자를 대상으로 경시적인 코호트 연구를 통하여 저준위 방사선 노출과 암 발생 위해도를 규명하고자 하였다. 방사선 노출에 관한 정보는 한국수력원자력(주)의 방사선 관리 DB에서 수집하였고, 암 발생에 관한 정보는 한국인 중앙 암 등록 자료를, 암 사망에 관한 정보는 통계청 사망원인 자료를 이용하여 수집하였다. 방사선 노출과 암 발생 위해도는 표준화 암 사망비(SMR)와 표준화 암 발생 비(SIR)로 평가하였다. 노출 군에서 암 발생에 대한 상대위험도는 1.08로 평가되었으나 전체 암에 대한 SIR은 0.81로 유의성이 관찰되지 않았다. 암 사망에 대한 상대위험도는 1.21 이었으나 전체 암에 대한 SMR도 0.86으로 역시 유의성은 관찰되지 않았다. 암 유형별 양상은 우리나라 일반인과 유사한 결과를 보였으며, 방사선량 증가에 따른 양-반응 관계 또한 확인되지 않았다.