• 한국입자에어로졸학회지
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• 제12권1호
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• pp.1-9
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• 2016

In this work, we evaluated the characteristics of flow field and uniformity of the nose-only exposure chambers for the inhalation toxicity test. Computational fluid dynamics (CFD) modeling was carried out to demonstrate uniformity of the nose-only exposure chambers. Because it is very important in the inhalation toxicity experiments that test materials are distributed uniformly to each holder of the chamber. The test was done with these 3 types of chamber with different form to develop inhalation toxicity evaluation system, easy-to-operate system among exposure chamber used for evaluating inhalation toxicity of environmental chemical mixtures. Through CFD interpretation, nose-only exposure chamber was made with the selection of the optimal conditions. For its evaluation, one type of fragrance was selected and measured particle size distribution of each port. The gene becoming luminous to green fluorescence was combined with GPT-SPE, a type of tGFP vector, to be inhaled to the mouse. Based on this, luminous intensity was checked. As a result, total particle number concentration of each port had average value of $3.17{\times}10^6{\sharp}/cm^3$ and range of the highest and lowest concentration value was approximately ${\pm}4.8%$. Autopsy of lung tissues of mouse showed that it had clearly better delivery of gene compared to the control group.

• 대한임상독성학회지
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• 제18권1호
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• pp.34-41
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• 2020

Purpose: This study evaluated aggressive hyperbaric oxygen therapy (HBOT) by understanding various exposure routes of acute carbon monoxide (CO) poisoning, the risk factors causing acute cardiovascular, and neurological toxicity caused by poisoning. Methods: A retrospective study was conducted based on the medical records of 417 acute CO poisoning patients who visited the emergency care unit from March 2017 to August 2019. The exposure routes, HBOT performance, age, sex, medical history (hypertension, diabetes mellitus, ischemic heart disease, heart failure), intentionality, loss of consciousness (LOC), intake with alcohol or sedatives, and initial test results (carboxyhemoglobin (COHb), troponin-I, electrocardiography, echocardiography, brain MRI) were examined. Comparative analysis of the clinical information was conducted between the groups that showed acute cardiovascular toxicity and neurological toxicity, and groups that did not. Results: Among 417 patients diagnosed with acute CO poisoning, 201 cases (48.2%) were intentional, and charcoal briquette was the most common route (169 patients (40.5%)). Two hundred sixteen cases (51.8%) were accidental, and fire was the most common route (135 patients (32.4%)). The exposure route was more diverse with accidental poisoning. Three hundred ninety-nine patients were studied for acute cardiovascular toxicity, and 62 patients (15.5%) were confirmed to be positive. The result was statistically significant in intentionality, LOC, combined sedatives, initial COHb, HTN, and IHD. One hundred two patients were studied for acute neurological toxicity, which was observed in 26 patients (25.5%). The result was statistically significant in age and LOC. Conclusion: Active HBOT should be performed to minimize damage to the major organs by identifying the various exposure routes of CO poisoning, risk factors for acute cardiovascular toxicity (intentionality, LOC, combined sedatives, initial COHb, HTN, IHD), and the risk factors for acute neurological toxicity (age, LOC).

• 대한방사선방어학회:학술대회논문집
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• 대한방사선방어학회 2010년도 춘계 학술발표회 및 심포지엄
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• pp.238-239
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• 2010

• 비파괴검사학회지
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• 제22권5호
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• pp.490-499
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• 2002

국내 감마선투과검사용 조사장치는 1,000여대로 2,500여명의 종사자가 대부분 수동으로 원격 조작하는 실정으로 작업의 효율화와 방사선피폭 저감화를 위하여 자동 원격조작기의 사용이 요구된다. 이에 연구팀은 실무에 적합한 토크와 안전계수로부터 $54kgf{\cdot}cm$의 출력을 지닌 24V, 200W의 BLDC모터를 이용하여 $0.4{\sim}1.2m/s$ 범위의 선원 이동 속도를 조절할 수 있는 구동장치와 RF 센서로 구동 속도 조절, 광전센서에 의한 선원 위치 및 timer로 노출시간을 제어할 수 있는 무선 원격조작기를 개발하였다. 이와 같이 개발한 자동원격조작기는 AC 와 DC 겸용, 그리고 기존의 수통 원격조작기에 탈착이 가능하여 자동과 수동을 겸용할 수 있는 경제적 이점 등으로 활용도가 클 것으로 기대된다.

• 한국의학물리학회지:의학물리
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• 제9권1호
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• pp.55-64
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• 1998

고선량률 원격 강내조사 선원은 전량 외국에서 수입되어 왔으며, 최근 Co-60 소선원의 공급부진으로 초기 도입시의 치료시간에 비해 4내지 5배의 시간을 조사하게 되어 대체용 선원의 개발이 크게 요구되고 있다. 이 연구는 국내 하나로 원자로의 중성자를 이용하여 $^{191}$ Ir(n,Υ)$^{192}$ Ir 핵반응을 일으켜 Ir-192 선원 2.87 Ci (밀봉 1.012 Ci)를 생산하고, 고선량률 원격 강내조사선원의 선량특성을 조사하였다. 제작선원에 대한 조사선량률은 아크릴 지지체의 중앙에 아크릴 아프리케이터를 고정하고 선원의 중심으로부터 각각 5, 10, 20 cm 거리에 전리함을 설치하여 일정시간 선원을 노출시켜 측정한 결과 6.36 $\pm$ 0.147 Rm$^2$/GBq-hr (2.350 $\pm$ 0.054 R$cm^2$/mCi-hr)을 결정하였으며, 측정오차는 1$\sigma$ 는 2.2% 였다. 계산선량은 조사선량률 상수 4.69 R$cm^2$/h-mCi 와 Ir-192 에너지 스펙트럼을 이용한 선원자체 및 철에 대한 질량흡수계수를 통해 구했으며, 실제 측정선량과 평균 3.8 % 오차범위에서 일치하였다. 선량 등방성은 선원의 측방향과 축 및 대각선방향으로 전리함을 이용하여 측정한 결과 3 % 이내 균등한 선량을 나타내었으며, 필름선량에서도 균등선량분포를 확인할 수 있었으며, Co-60 선원과 유사한 선량분포를 얻었을 수 있었다. 특히 본 연구의 선량특성조사는 강내조사선량선원 대체용의 선원개발과 선량계획 전산화의 근거가 될 것으로 믿는다.

• Safety and Health at Work
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• 제13권2호
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• pp.227-234
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• 2022

Background and Purpose: In 2021, lung cancer in school food workers was first recognized as an occupational cancer. The classification of the carcinogenicity of cooking fumes by International Agency for Research on Cancer (IARC) was based on Chinese epidemiological data. This study aimed to determine the hazard levels of school cooking fumes in Korea. Materials and Methods: Based on public school cafeterias in one area, 25 locations were selected for the survey according to the number per school type, ventilation states, and environmental pre-assessments of cafeterias. Two inside cooking areas using a heat source and one outside cooking area were selected as control measurement points. Measurements of CO, CO₂, polycyclic aromatic hydrocarbons (PAHs), and total volatile organic compounds (TVOCs), including benzene, formaldehyde, and particulate matter (PM10, PM2.5, PM1, respectively), were taken. The concentrations and patterns of each substance in the kitchens were compared with the outdoor air quality. Result: Known carcinogens, such as the concentrations of PAHs, formaldehyde, TVOC (benzene), and particulate matter in school cooking fumes, were all detected at similar or slightly higher levels than those found outside. Additionally, substances were detected at relatively low concentrations compared to the Chinese cooking fumes reported in the literature. However, the short-term exposure to high concentrations of CO (or composite exposure with CO₂) and PM2.5 in this study were shown. Conclusion: The school cooking fumes in South Korea was a relatively less harmful than Chinese cooking fumes, however short-term, high exposure of toxic substances can cause a critical health effect.

• Safety and Health at Work
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• 제14권4호
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• pp.488-491
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• 2023

This study aims to ascertain occupations potentially at greatest risk of exposure to SARS-CoV-2 based on pre-lockdown working conditions in France. We combined two French population-based surveys documenting workplace exposures to infectious agents, face-to-face contact with the public, and working with colleagues just before the pandemic. Then, for each 87-level standard French occupational grouping, we estimated the number and percentage of the French working population reporting these occupational exposure factors, by gender, using survey weights. As much as 40% (11 million) of all workers reported at least two exposure factors. Most of the workers concerned were in the healthcare sector. However, army/police officers, firefighters, hairdressers, teachers, cultural/sports professionals, and some manual workers were also exposed. Women were overrepresented in certain occupations with potentially higher risks of exposure such as home caregivers, childminders, and hairdressers. Our gender-stratified matrix can be used to assign prelockdown work-related exposures to cohorts implemented during the pandemic.

• Fisheries and Aquatic Sciences
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• 제12권4호
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• pp.350-353
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• 2009

As a result of human industrial development, carbon dioxide ($CO_2$) is currently accumulating in the atmosphere and dissolving into the oceans. Sequestration into the deep sea has been proposed as a possible solution to this increasing atmospheric $CO_2$, although the impact of such a program on marine ecosystems is unknown. We examined the effects of increased $CO_2$ levels on the growth of the olive flounder, Paralichthys olivaceus. Juvenile olive flounder 40 days post hatching were exposed to two levels of $CO_2$ (3.60-7.55 and 4.05-11.46 kPa) in running seawater for 26 days. During the exposure period, the pH and $CO_2$ levels of the water were measured, and the numbers of dead individuals were counted in each aquarium. Following the exposure period, the total lengths (mm) and body weights (mg) of the juvenile fish were measured. Both $CO_2$ treatments significantly increased fish mortality compared to controls ($19.87\pm4.53%$ vs. 7.14% and $75.96\pm1.36%$ vs. 7.14% for high and low doses, respectively). After the high $CO_2$ treatment, total length ($14.98\pm6.58$ mm vs. $19.52\pm1.83$ mm) and body weight ($28.92\pm13.85$ mg vs. $67.35\pm18.32$ mg) of the exposed flounder were reduced compared to the control fish; however, no significant differences in these values were observed after the low $CO_2$ dose. These results suggested that $CO_2$ exposure inhibits growth in the juvenile stage and that $CO_2$-enriched seawater is toxic in the early life stages of olive flounder.

• Journal of Radiation Protection and Research
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• 제33권4호
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• pp.135-141
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• 2008

본 논문은 벼에 $^{14}CO_2$ 가스를 단기간 동안 직접 노출시켜 시간대 별 $^{14}C$의 전이 현상에 대한 동적 예측 모델과 동 모델의 타당성을 조사하기 위해 수행된 벼의 $^{14}CO_2$ 피폭 실험에 대해 기술하였다. 본 모델에서 작물은 몸체와 이삭(쌀알)의 두 격실로 구분되었고, 식물의 광합성과 연관된 매개변수의 함수로 표현되는 5개의 격실 간 탄소이동을 고려하였다. 모델예측을 통해 작물의 $^{14}C$ 방사능 오염에 대한 $^{14}CO_2$, 누출 시기 및 지속시간, 매개변수의 영향을 분석하였다. $^{14}CO_2$ 누출 지속시간이 길어지면 본 모델은 비 방사능 모델 적용 영역으로 수렴되었다. 작물의 $^{14}C$ 오염은 광합성이 가장 왕성한 개화기부터 수확기 사이에 작물이 $^{14}CO_2$에 노출되었을 때 가장 큰 것으로 예측되었다. $^{14}CO_2$에 대한 벼 노출 실험결과와 모델예측결과의 비교로부터 본 모델은 벼의 $^{14}C$ 흡수 예측 모델로 충분히 활용할 수 있음을 확인하였다.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1231-1242
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• 2020

The Kori Unit 1 will be decommissioned after a permanent shutdown in June 2017. South Korea has a 0.1 mSv/yr exposure limit standard for limited or unlimited site release. This is South Korea's first commercial NPP; therefore, if the containment building is reused as a memorial hall, it will contribute to the improvement of public understanding and enhance the public's acceptance of NPPs. Also, existing Kori Unit 1 nuclear power plant manpower resources can be reused after decommissioning and resident staff and memorial hall visitors can activate nearby commercial areas. Therefore, such a reuse scenario may also prevent an economic recession. The exposure dose was calculated using the following scenarios: worker in the containment building, visitor in the containment building, and worker in buildings other than the containment building. The exposure dose in the buildings was calculated by the RESRAD-BUILD developed by the Argonne National Laboratory (ANL). The preliminary exposure dose and derived concentration guideline level (DCGL) were derived.