• 한국학교ㆍ지역보건교육학회지
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• 제22권4호
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• pp.49-60
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• 2021

Objectives: Laboratories have various latent physical, chemical, biological, and ergonomical factors according to the diversification and fusion of research and development activities. This study aims to investigate the chemical exposure concentrations of college laboratories and evaluate their health risks, and use them as basic data to promote the health of college students. Methods: The sampling and analysis of harmful chemicals in the air in laboratories were performed using Method 1500 of the U.S. National Institute for Occupational Safety and Health (NIOSH)의 Method 1500. The harmful chemicals in the laboratories were divided into carcinogenic and non-carcinogenic chemicals. Risk assessment was performed using the cancer risk (CR) for carcinogenic chemicals and using the hazard index (HI) for non-carcinogenic chemicals. Results: The harmful chemicals in college laboratories consisted of acetone, diethyl ether, methylene chloride, n-hexane, ethyl acetate, chloroform, tetrahydrofuran, toluene, and xylenes. They showed the highest concentrations in laboratories A (acetone 0.001~2.34ppm), B (chloroform 0.95~6.35ppm), C (diethyl ether 0.08~8.68ppm), and D (acetone 0.07~14.96ppm). The risk assessment result for non-carcinogenic chemicals showed that the HI of methylene chloride was 2.052 for men and 2.333 for women, the HI of N-hexane was 4.442 for men and 5.05 for women. Thus, the HI values were higher than 1. The risk of carcinogenic chemicals is determined by an excess cancer risk (ECR) value of 1.0×10^-5, which means that one in 100,000 people has a cancer risk. The ECRs of chloroform exceeded 1.0×10^-5 for both men and women, indicating the possibility of cancer risk. Conclusion: College laboratories showed the possibility of non-carcinogenic health risks for methylene chloride, n-hexane, tetrahydrofuran (THF), toluene, and xylenes, and carcinogenic health risks for chloroform, methylene chloride. However, this study used the maximum values of measurements to determine the worst case, and assumed that the subjects were exposed to the corresponding concentrations continuously for 8 hours per day for 300 days per year. In consideration of the nature of laboratory environment in which people are intermittently exposed, rather than continuously, to the chemicals, the results of this study has an element of overestimation.

• 대한한방내과학회지
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• 제43권3호
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• pp.363-374
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• 2022

Objective: This study was conducted to evaluate the hypoglycemic effect and safety of herbal extracts in patients with type 2 diabetes mellitus. Methods: We investigated 19 hospitalized patients with type 2 diabetes mellitus who were administered Banhasasim-tang (BST), Gumiganghwal-tang (GGT), or Pyeongwee-san (PWS) at Kyung Hee University Korean Medical Hospital for at least three days between January 2012 and December 2021. Their clinical characteristics and laboratory tests were reviewed retrospectively. The glucose-lowering effect of the herbal extracts was assessed by comparing blood glucose levels, including fasting blood sugar (FBS), two-hour postprandial glucose (PP2) levels, and glycated hemoglobin levels. To evaluate the safety of the herbal extract, liver function test and kidney function test results were compared, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine (Cr). Results: After taking herbal extracts, PP2 and HbA1c levels significantly decreased from 205.82 mg/dL to 171.41 mg/dL and 7.58% to 6.62%, respectively. The safety profile reported no significant difference after taking herbal extracts. Conclusions: BST, GGT, and PWS may have hypoglycemic effects in patients with type 2 diabetes mellitus taking hypoglycemic medication.

• Fisheries and Aquatic Sciences
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• 제25권12호
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• pp.626-636
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• 2022

Shellfish are exoskeleton-bearing aquatic invertebrates that consume various organic and inorganic substances floating in seawater through filter feeding. Heavy metals are known as absorbed and accumulated in seawater. Some of the toxic heavy metals are highly accumulated in seawater, and exposure to them can cause a variety of risks to the human body. Since Koreans like to eat seafood, they are more likely to be exposed to contaminated seafood with heavy metals. In this study, nine types of heavy metals were analyzed on ten different shellfish species in the coastal area of South Korea. The risk assessment was also done on shellfish in which heavy metals were detected. Zinc (Zn) and copper (Cu) were identified at an average of 56.7 mg/kg (6.70 to 466 mg/kg) and 13.2 mg/kg (0.064 to 143 mg/kg), respectively. Lead (Pb) average of 0.208 mg/kg (0.000750 to 1.02 mg/kg), cadmium (Cd) average of 0.454 mg/kg (0.0388 to 1.56 mg/kg) and mercury (Hg) average of 0.0266 mg/kg (0.00548 to 0.174 mg/kg) were identified. Additionally, arsenic (As), chromium (Cr), nickel (Ni), and silver (Ag) were also identified as average concentrations of 4.02 (0.460 to 15.0 mg/kg), 0.167 (< limit of quantification [LOQ] to 0.820 mg/kg), 0.281 (< LOQ to 1.46 mg/kg), and 0.158 mg/kg (< LOQ to 1.15 mg/kg). The result indicates that the monitoring results of heavy metals in most shellfish satisfied the Korean standard. However, Pb and Cd have exceeded some foreign standards, such as the United States and the EU. The permissible human exposure calculated using the heavy metal intake and detection amount was lower than the Joint FAO/WHO Expert Committee on Food Additives human safety standard, and the risk of heavy metals from shellfish consumption was at an acceptable level.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4571-4584
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• 2022

The analysis of rapid flow transients in Reactor Coolant Pumps (RCP) is essential for a reactor safety study. An accurate and precise analysis of the RCP coastdown is necessary for the reactor design. The coastdown of RCP affects the coolant temperature and the colloidal crud in the primary coolant. A realistic and kinetic model has been used to investigate the behavior of activated colloidal crud in the primary coolant and steam generator that solves the pump speed analytically. The analytic solution of the non-dimensional flow rate has been determined by the energy ratio β. The kinetic energy of the coolant fluid and the kinetic energy stored in the rotating parts of a pump are two essential parameters in the form of β. Under normal operation, the pump's speed and moment of inertia are constant. However, in a coastdown situation, kinetic damping in the interval has been implemented. A dynamic model ACCP-SMART has been developed for System Integrated Modular and Advanced Reactor (SMART) to investigate the corrosion due to activated colloidal crud. The Fickian diffusion model has been implemented as the reference corrosion model for the constituent component of the primary loop of the SMART reactor. The activated colloidal crud activity in the primary coolant and steam generator of the SMART reactor has been studied for different equilibrium corrosion rates, linear increase in corrosion rate, and dynamic RCP coastdown situation energy ratio b. The coolant specific activity of SMART reactor equilibrium corrosion (4.0 mg s^-1) has been found 9.63×10^-3 µCi cm^-3, 3.53×10^-3 µC cm^-3, 2.39×10^-2 µC cm^-3, 8.10×10^-3 µC cm^-3, 6.77× 10^-3 µC cm^-3, 4.95×10^-4 µC cm^-3, 1.19×10^-3 µC cm^-3, and 7.87×10^-4 µC cm^-3 for ²⁴Na, ⁵⁴Mn, ⁵⁶Mn, ⁵⁹Fe, ⁵⁸Co, ⁶⁰Co, ⁹⁹Mo, and ⁵¹Cr which are 14.95%, 5.48%, 37.08%, 12.57%, 10.51%, 0.77%, 18.50%, and 0.12% respectively. For linear and exponential coastdown with a constant corrosion rate, the total coolant and steam generator activity approaches a higher saturation value than the normal values. The coolant and steam generator activity changes considerably with kinetic corrosion rate, equilibrium corrosion, growth of corrosion rate (ΔC/Δt), and RCP coastdown situations. The effect of the RCP coastdown on the specific activity of the steam generators is smeared by linearly rising corrosion rates, equilibrium corrosion, and rapid coasting down of the RCP. However, the time taken to reach the saturation activity is also influenced by the slope of corrosion rate, coastdown situation, equilibrium corrosion rate, and energy ratio β.

• 한국터널지하공간학회 논문집
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• 제12권1호
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• pp.75-85
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• 2010

본 연구는 새로 개발된 쉴드 TBM 테일 보이드 동시주입용 무기계 가소성 그라우트의 현장적용 가능성을 평가하기 위하여 체적변화성 및 투수계수를 측정하였으며, 환경영향성 평가를 실시하였다. 또한, 무기계 가소성 그라우트의 현장 시험 시공에 앞서, 쉴드 TBM 모형주입장치 및 후방주입 공동충전 시험체를 이용하여 실내실험을 실시하였으며, 실제 서울 전력구 쉴드 TBM 시공현장에 시험시공을 수행하였다. 기중에서 14일 양생시킨 공시체를 이용해서 무기계 가소성 그라우트의 체적 변화성을 평가한 결과, 무기계 가소성 그라우트의 체적변화는 거의 발생하지 않았다. 그리고 투수계수를 측정하여 비교한 결과 무기계 가소성 그라우트의 우수한 차수효과를 확인 할 수 있었다. 어독성 시험과 용탈시험을 통한 환경영향성 평가를 수행한 결과, 무기계 가소성 그라우트의 경우 평균 pH가 8.0으로 측정되었으며, 96시간 경과 후 10%의 폐사율을 보였다. 용탈액에 대한 원자흡광분광 시험 결과 용탈에 의한 유해 중금속 성분은 수질관리 기준치 이하로 검출되었다. 가소성 그라우트의 현장 적용성 실험을 위하여 실내 모형실험을 수행한 결과 충전성은 확보되었으며, 실제 시공현장에 적용한 결과 우수한 주입성을 보였다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.19-19
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• 2021

경남 양산의 천성산에서만 생육하는 산림청·국립수목원 지정 희귀식물(Critically Endangered, CR) 주걱댕강나무 개체군을 대상으로 20개소의 방형구(10×10m, 100m²) 내 개체의 특성(개체수, 개화, 결실 등), 종자의 활력검정, 차광처리에 따른 생육 특성 및 우리나라 전역의 생육가능성에 대해 알아보았다. 20개소의 대상지에서 확인한 개체수는 총 3,270개체이며, 평균 개체밀도는 1.635/m²이다. 평균 수고는 1.1m 정도이며, 평균개화율은 27.37%이고 개화는 1.0~1.8m(평균수고 1.39m) 수고에서 집중되었다. 한편, 결실률은 평균 1.67%로 매우 낮았다. 종자의 크기는 평균 너비 0.27mm, 높이 0.18mm 정도로 너무 작아 X-ray 촬영을 통한 충실검정은 확인할 수 없었다. 종자를 1% Agar배지에 종자를 치상한 후 온도조건(15, 20, 25℃)에 따른 실험 및 온도(15, 20, 25℃)와 GA3 농도(100, 250, 500PPM)처리 실험 모두 발아율은 0%였다. 결실률이 매우 낮고, 종자 발아율 또한 낮으며 지하경을 뻗는 특성으로 보아 종자는 휴면종자이며 영양생장을 취하는 것으로 판단된다. 차광처리에 따른 생육 특성 실험 결과, 신초는 평균 30.6mm 성장, 엽록소 평균 함량 25.30, 잎의 수 평균 8.32개, 잎 길이 평균 35.93mm, 잎 폭 평균 20.37mm정도 성장하여 엽면적은 평균 761.10mm로 나타났다. 생육은 조도계를 활용한 실 차광률로 볼 때, 67.8% > 82.8% > 88.2% > 43.2% > 91.9%의 순서로 나타났다. 주걱댕강나무 자생지 내 수관열림도가 21.86%로 이를 차광률로 환산할 경우 70%내외의 차광률에서 생육이 효율적인 것을 확인하였다. 기후대별로 5개소에 이식한 주걱댕강나무는 이듬해까지 모두 생육이 원활하였다. A. spathulata를 Diabelia ionostachya종들과 가까운 유연관계를 가진다는 연구에서 D. ionostachya 샘플은 위도상 강원도 고성군에 속하고 있어 우리나라 대부분 지역에서 식재가 가능할 것으로 판단된다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.21-21
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• 2021

주걱댕강나무는 경남 양산의 천성산에서만 생육하는 산림청·국립수목원 지정 희귀식물(Critically Endangered, CR)로 현지외 보전 및 대체 서식지 조성을 위해 번식 특성에 대해 알아보았다. 종자번식의 경우 450립의 종자를 저장방법에 따라 파종한 결과 노천매장 3.56%, 저온건조저장 0.67%, 습사저온저장 0.22%로 발아율이 매우 저조하였으며, 배양토 조건에 따라 직파 실험한 결과 모래 2.44%, 원예용 상토 2.22%, 현지내 산림토 1.11%, 현지외 산림토 0%로 이 또한 발아율이 매우 저조하였다. 삽목번식의 경우 숙지삽은 모래+펄라이트 36.1%, 모래 31.1%, 원예용 상토 20.0%로 나타났으며, 휴면지 삽수의 발근촉진제 처리 효과는 IBA 1,000PPM에서 37.8%, IBA 7,000PPM 30.0%, 무처리 28.9%, IBA 5,000PPM 27.8%의 발근율을 보였고 신초길이, 뿌리의 수, 뿌리 길이는 전반적으로 발근촉진제 처리와 함께 농도가 높아질수록 뿌리 성장이 왕성한 것으로 나타났다. 녹지삽은 모래 80%, 모래+펄라이트 76.7%, 피트모스+마사토 73.3%, 피트모스+펄라이트+버미큘라이트 70.0% 순이며, 왕모래와 왕모래+마사토는 26.7%와 36.7%로 다소 저조하였다. 녹지삽수의 굵기는 4mm이상 구간에서 발근율이 73.3%로 가장 높았으며, 녹지삽수의 길이는 7~8cm 구간에서 80.0%로 가장 높게 나타나 삽수의 굵기가 굵고 8cm내외의 길이가 효율적인 것으로 나타났다. 근삽은 발아율이 88.3~96.7%로 모든 배양토에서 높게 나타났다. 근삽수 직경 7~8mm에서 100%이며 3~4mm 또한 91%로 나타났다. 근삽수 길이는 4~5cm와 10~11cm에서 100%, 6~7cm 88.1%, 8~9cm 94.4%로 나타나 4~5cm를 제외하고는 삽수 길이가 길수록 신초 생장과 발근이 비례하는 것을 확인하였다. 주걱댕강나무는 실생보다 삽목번식이 더 효율적이며, 그 중 근삽이 가장 발근율이 높다. 배양토는 모래 단용구를 제외하고는 평균 95%이상으로 나타났으며, 근삽수는 직경이 굵고 길수록 신초 생장과 발근이 왕성하다. 따라서, 현지외 보전을 위해 향후 휴면성의 종자 발아 연구가 필요하며, 영양번식을 할 경우 근삽이 가장 효율적인 것을 확인하였다.

• 한국환경복원기술학회지
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• 제27권3호
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• pp.45-56
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• 2024

Heavy metals emitted from urban development do not decompose in the soil and remain for long periods, continually impacting the environment. Since the mid-1990s, there has been increasing societal concern in South Korea regarding soil contamination, prompting various legislative revisions to reduce pollution. This study utilizes the Environmental Impact Assessment Support System (EIASS) to investigate projects in the metropolitan area that have exceeded the Ministry of Environment's soil contamination concern levels from 1989 to 2022 and to examine improvements in the environmental impact assessment (EIA) process. The results reveal that the average concentrations of nine contaminants-cadmium (Cd), copper (Cu), arsenic (As), mercury (Hg), lead (Pb), hexavalent chromium (Cr6+), zinc (Zn), nickel (Ni), and fluoride (F)-have all increased over the years. Among these, Zn had the highest relative proportion, with 37.5% of the 40 sites exceeding environmental concern levels. Investigation of 19 specific projects at these exceedance sites showed that only 7 had documented analyses of contamination causes and remediation plans, and just one had contracted additional remediation services, though results from these efforts were found to be lacking. Furthermore, since 2019, a significant proportion of these sites were involved in residential developments, likely due to government initiatives in new city development and extensive housing supply plans. This research emphasizes the importance of public disclosure of the processes and outcomes of remediation efforts on historically contaminated soils prior to project development. It discusses improvements to the EIA by reviewing current legislation and international examples. The findings of this study are expected to heighten public awareness about heavy metal contamination and enhance transparency in soil remediation efforts, contributing to sustainable environmental management and development.

• Journal of Nutrition and Health
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• 제57권3호
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• pp.349-364
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• 2024

본 연구는 AHP를 적용하여 영양교사 및 영양사의 학교급식 식단 작성 시 고려 요인들의 상대적 중요도를 학교급별로 비교함으로써 효율적인 학교급식 식단 구성 방안에 대한 기초자료를 제공하고자 하였다. 모집단인 전국 유·초·중·고·특수학교 20,548개교를 대상으로 표본을 추출하여 총 395부 중 166부를 회수하였고, SPSS 통계 프로그램을 이용하여 CR이 0.2 이하인 응답에 대해 분석을 진행하였다. AHP를 이용하여 학교급식 식단 구성의 각 분야별 상대적 중요도를 분석한 결과 조리 인력 및 시설, 기호도, 영양의 균형, 조리 과정, 식재료 순으로 높게 나타났으며, 각 분야의 가장 중요한 하위 영역은 조리종사자의 숙련도, 급식대상자의 기호도, 영양소 섭취 기준, 위생, 식품비 예산이었으며, 이는 각 학교급에서 가장 높은 비율을 차지하였다. 더불어 급식 대상자의 기호도, 영양소 섭취 기준, 식품비 예산은 식단 작성 시 어려운 점의 상위 3가지 항목과도 일치해 식단 작성 시 반영이 어려울수록 상대적 중요도가 높게 나타남을 확인할 수 있었다. 본 연구는 향후 학교급식 식단 구성 및 관리 업무 효율 증대에 기여하며 정책 운영 방향 설정을 위한 기초자료로 활용될 수 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.547-561
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• 2024

In this study, we aim to investigate the precise alterations in the gut microbiota during the onset and advancement of diabetic nephropathy (DN) and examine the impact of Ruminococcus gnavus (R. gnavus) on DN. Eight-week-old male KK-Ay mice were administered antibiotic cocktails for a duration of two weeks, followed by oral administration of R. gnavus for an additional eight weeks. Our study revealed significant changes in the gut microbiota during both the initiation and progression of DN. Specifically, we observed a notable increase in the abundance of Clostridia at the class level, higher levels of Lachnospirales and Oscillospirales at the order level, and a marked decrease in Clostridia_UCG-014 in DN group. Additionally, there was a significant increase in the abundance of Lachnospiraceae, Oscillospiraceae, and Ruminococcaceae at the family level. Moreover, oral administration of R. gnavus effectively aggravated kidney pathology in DN mice, accompanied by elevated levels of urea nitrogen (UN), creatinine (Cr), and urine protein. Furthermore, R. gnavus administration resulted in down-regulation of tight junction proteins such as Claudin-1, Occludin, and ZO-1, as well as increased levels of uremic toxins in urine and serum samples. Additionally, our study demonstrated that orally administered R. gnavus up-regulated the expression of inflammatory factors, including nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) and Interleukin (IL)-6. These changes indicated the involvement of the gut-kidney axis in DN, and R. gnavus may worsen diabetic nephropathy by affecting uremic toxin levels and promoting inflammation in DN.