• Journal of Microbiology and Biotechnology
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• 제22권9호
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• pp.1296-1300
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• 2012

The feasibility of using Deinococcus showing strong resistance to both desiccation and ionizing radiation as a dose indicator of gamma radiation exposure was evaluated. Three Deinococcus strains having different levels of radiation resistance, Deinococcus radiodurans (DRD), Deinococcus radiopugnans (DRP), and the DRD pprI mutant (DRM), were selected to develop an appropriate dose indicator for a broad range of exposures. DRD, DRP, and DRM cultures with different numbers of cells [${\sim}10^7$ to $10^3$ colony forming units (CFU)/$100{\mu}l$] were lyophilized and subjected to various doses of gamma radiation to determine a critical dose that inhibited bacterial growth completely. Finally, a combination of DRD at ${\sim}10^7$ and ${\sim}10^6$ CFU, DRP at ${\sim}10^5$ CFU, and DRM at ${\sim}10^4$ CFU successfully indicated exposure to 5, 10, 20, and 30 kGy of gamma radiation, respectively. This study shows the possibility of developing a qualitative indicator of radiation exposure using Deinococcus.

• Nuclear Engineering and Technology
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• 제50권7호
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• pp.1088-1098
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• 2018

Kori unit #1, which is the first commercial nuclear power plant in Korea, was permanently shutdown in June 2017, and it is about to be decommissioned. Currently in Korea, researches on the decommissioning technology are actively conducted, but there are few researches on workers internal exposure to radioactive aerosol that is generated in the process of decommissioning nuclear power plants. As a result, the over-exposure of decommissioning workers is feared, and the optimal working time needs to be revised in consideration of radioactive aerosol. This study investigated the annual exposure limits of various countries, which can be used as an indicator in evaluating workers' internal exposure to radioactive aerosol during pipe cutting in the process of decommissioning nuclear power plants, and the growth and dynamics of aerosol. Also, to evaluate it, the authors compared/analyzed the cases of aerosol generated when activated pipes are cut in the process of nuclear power plants and the codes for evaluating internal exposure. The evaluation codes and analyzed data conform to ALARA, and they are believed to be used as an important indicator in deriving an optimal working time that does not excess the annual exposure limit.

• Safety and Health at Work
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• 제12권4호
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• pp.439-444
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• 2021

Background: In a previous study, we estimated exposure prevalence and the number of workers exposed to carcinogens by industry in Korea. The present study aimed to evaluate the optimal exposure intensity indicators of airborne lead exposure by comparing to blood lead measurements for the future development of the carcinogen exposure intensity database. Methods: Data concerning airborne lead measurements and blood lead levels were collected from nationwide occupational exposure databases, compiled between 2015 and 2016. Summary statistics, including the arithmetic mean (AM), geometric mean (GM), and 95th percentile level (X95) were calculated by industry both for airborne lead and blood lead measurements. Since many measurements were below the limits of detection (LODs), the simple replacement with half of the LOD and maximum likelihood estimation (MLE) methods were used for statistical analysis. For examining the optimal exposure indicator of airborne lead exposure, blood lead levels were used as reference data for subsequent rank correlation analyses. Results: A total of 19,637 airborne lead measurements and 32,848 blood lead measurements were used. In general, simple replacement showed a higher correlation than MLE. The results showed that AM and X95 using simple replacement could be used as optimal exposure intensity indicators, while X95 showed better correlations than AM in industries with 20 or more measurements. Conclusion: Our results showed that AM or X95 could be potential candidates for exposure intensity indicators in the Korean carcinogen exposure database. Especially, X95 is an optimal indicator where there are enough measurements to compute X95 values.

• 대한환경공학회지
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• 제34권1호
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• pp.7-15
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• 2012

Indicator PCB의 농도 수준은 2006년에 세계보건기구(WHO) 프로토콜에 따라 수집된 132개의 모유(초유, 출산 후 30일째 모유, 출산 후 60일째 모유)로 분석하였다. Indicator PCBs의 농도는 고분해능 가스크로마토그래피/고분해능 질량분석기를 이용한 동위원소희석법으로 측정되었으며, 이 방법은 국제적 경향을 비교 평가하기 위한 정확하고 정밀한 데이터를 제공한다. 또한, 모든 분석 결과를 토대로 평균일일섭취량(ADIs)이 계산되었다. 총 indicator PCBs의 중앙값은 14 ng/g lipid로, 다른 나라에서 검출된 농도보다 현저하게 낮았으며, PCBs 138, 153, 180은 분석한 지표 이성질체 합의 약 65%를 차지하였다. 가장 기여율이 높은 PCB 153은 총 indicator PCBs 농도와 매우 높은 상관관계를 나타내었다(p<0.001). PCBs 농도는 산모의 아이수가 증가할수록 확연히 감소하였고, 산모의 PCBs 축적과 배출에 있어 출산경력과 수유기간은 중요한 인자로 나타났다. 6개월 모유수유 기간 동안 총 indicator PCBs의 평균일일섭취량의 중앙값은 $0.077{\mu}g/kg{\cdot}bw/day$이었다. 초산부 모유 중 PCB 118의 농도는 1998년에 비해 25~35% 정도 감소하였으며, 이러한 경향은 지속될 것이라는 것을 보여준다.

• Journal of Radiation Protection and Research
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• 제47권1호
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• pp.22-29
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• 2022

Background: A comprehensive, traceable, and easy-to-understand radiation risk indicator is desired for radiological protection. The early-onset hypothesis could be used for this purpose. Materials and Methods: An indicator for early death (IED) was developed and calculated using the epidemiological dataset from the 14^th Report of the Life Span Study (LSS) of Hiroshima and Nagasaki. By clarifying the calculation process, IED for all-cause mortality was estimated. In addition, the characteristics of IED for solid cancer mortality and cardiovascular mortality as well as those of men and women, and their dependence on age at exposure were investigated for detailed analysis. Results and Discussion: The IED for all-cause mortality was estimated to be approximately 4 years for an acute radiation exposure of 1 Gy regardless of the fitting dose range. The cumulative death rate for all solid cancers also indicated the early-death tendency (approximately 7-10 years at 1 Gy). Although, there is a slight difference in the characteristics of the risk obtained from the LSS study and this study, it is considered that the IED in a unit of years can also be used to show the overall picture of risk due to radiation exposure. Conclusion: We developed and calculated the indicator for early death, IED, for the cumulative mortality rate of all causes of death, all solid cancers, and circulatory diseases. The quantitative values of IED were estimated to be 4 years for all causes of death, 7-10 years for all solid cancers. IED has an advantage for intuitively understanding the meaning of radiation risk since it can be obtained by a simple and traceable method.

• 한국안전학회지
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• 제29권1호
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• pp.64-69
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• 2014

Community-based disaster preparedness approaches are increasingly important elements of vulnerability reduction and disaster strategies. They are associated with a policy trend that values the knowledge and capacities of local people. In this research, we describe the community diagnosis method and develop Flood Disaster Risk Reduction Index(FDRRI) for assessment of flood vulnerability. FDRRI is composed of four indicators such as Flood Exposure Indicator(FEI), Sensitivity Indicator(SI), Risk Reduction Indicator(RRI), and Community Preparedness Indicator(CPI). We anticipate to present the guideline for selection national preparedness projects and uplift community's preparedness capacity.

• 대한방사선기술학회지:방사선기술과학
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• 제38권1호
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• pp.51-61
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• 2015

모든 방사선 검사는 검사를 결정하고 실행하는 과정에서 정당성이 확보되어야하고 피폭선량과 영상의 화질에 대한 최적화가 이루어져야 할 뿐만 아니라 ALARA의 원칙에 따라 최소의 방사선을 사용하여 최적의 임상 정보를 얻을 수 있어야 한다. CT 검사는 방사선 검사 중에서 많은 피폭을 환자에게 조사하는 검사이다. 특히 방사선 민감도가 높은 소아 환자의 CT 검사 있어서는 특별한 주의가 필요하다. 임상에서 CT선량에 대한 정확한 이해와 정보는 환자에게 불필요한 방사선 피폭을 줄이고 안전한 검사를 제공하기 위해 절대적으로 필요하다. 이에 본 연구에서는 여러 선행 연구의 고찰을 통하여 CT의 피폭선량에 대한 개념을 확인하고 CT장치의 선량 저감화를 위한 각 파라미터의 이해와 American Association of Physicists in Medicine (AAPM)report 204에서 소개하고 있는 환자의 사이즈에 따른 피폭선량의 보정방법인 Size-Specific Dose Estimates(SSDE)와 XR 25의 개념을 이해하고자 한다.

• Safety and Health at Work
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• 제8권1호
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• pp.1-10
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• 2017

Considerable effort has been made to address the issue of occupational health and environmental exposure to mercury. This review reports on the current literature of mercury exposure and health impacts on dental personnel. Citations were searched using four comprehensive electronic databases for articles published between 2002 and 2015. All original articles that evaluated an association between the use of dental amalgam and occupational mercury exposure in dental personnel were included. Fifteen publications from nine different countries met the selection criteria. The design and quality of the studies showed significant variation, particularly in the choice of biomarkers as an indicator of mercury exposure. In several countries, dental personnel had higher mercury levels in biological fluids and tissues than in control groups; some work practices increased mercury exposure but the exposure levels remained below recommended guidelines. Dental personnel reported more health conditions, often involving the central nervous system, than the control groups. Clinical symptoms reported by dental professionals may be associated with low-level, long-term exposure to occupational mercury, but may also be due to the effects of aging, occupational overuse, and stress. It is important that dental personnel, researchers, and educators continue to encourage and monitor good work practices by dental professionals.

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.279-288
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• 2002

According to the epidemiological studies in chromium workers, hexavalent chromium is associated with the risk of lung cancer. Cellular oxidative damages by reactive oxygen species produced by hexavalent chromium exposure may play an important role in the carcinogenesis process. We investigated the availabilities of malondialdehyde measurement for the assessments of oxidative damages from chromium exposure with an experimental inhalation study in vivo. Lipid peroxidation, one kind of cellular oxidative damage, was measured in blood plasma of the rats which inhaled the hexavalent chromium mist for 1, 2 and 3 weeks. The concentrations of malondialdehyde (MDA), the metabolite of lipid peroxidation, in all exposed groups were higher than those of controls with dose-dependant manner. The levels of MDA were also correlated with urine chromium levels of the rats. Therefore, MDA as an indicator of lipid peroxidation could be proper biologic marker for the assessment of the oxidative damage from chromium exposure, which might be involved in carcinogenesis.

• 한국패류학회지
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• 제28권4호
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• pp.305-312
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• 2012

나프탈렌이 바지락 (각장 $32.74{\pm}2.18mm$, 전중 $8.29{\pm}1.41g$) 의 생존, 성비 및 생식소발달에 미치는 영향에 대해 연구하였다. 노출농도는 대조구, solvent 대조구 (에탄올), 30, 60, 90, $120{\mu}g$ Nap $L^{-1}$ 였으며, 노출기간은 20주였다. 노출 종료 후 바지락의 생존율은 $60{\mu}g$ Nap $L^{-1}$ 이상의 농도에서 감소하였다. 성비는 대조구와 비교해 solvent 대조구 (에탄올)와 $30{\mu}g$ Nap $L^{-1}$ 실험구는 별다른 차이를 보이지 않았지만, $60{\mu}g$ Nap $L^{-1}$ 실험구의 경우 수컷의 비율이 높았다. 그 후 농도가 높아질수록 수컷의 비율이 감소하였다. 생식소 발달단계는 암컷의 경우 $60{\mu}g$ Nap $L^{-1}$ 이상의 농도에서, 수컷의 경우 $30{\mu}g$ Nap $L^{-1}$ 이상의 농도에서 발달이 지연되는 결과를 보였다. 생식소에서 관찰된 intersex는 암컷에서 16.28%, 수컷에서 1.68%를 나타냈다. 이러한 결과들을 볼 때 나프탈렌은 바지락의 생존 뿐 만 아니라 성비와 생식에 영향을 주는 것으로 보인다.