• Nuclear Engineering and Technology
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• 제22권2호
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• pp.83-94
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• 1990

울진 1&2호기의 사용후 핵연료 중간저장을 위한 기존 저장조용량확장 방안으로서 maximum density rack (MDR)에 consolidated fuel을 저 장하여 현 9/3 노심에서 32/3으로 확장할 경우 방사능 농도가 적정기준 이하로 유지될 수 있는지 여부를 분석하였다. 이를 위해 본 연구에서는 정화계통의 연속적 운전방식과 주기적 운전방식에 대한 저장용수중의 방사능 농도계산을 위한 두 가지 계산 모델을 만들어 상호비교 하였다. 이 결과 두 경우 모두 32/3 노심저장에 대하여 기존 정화계통으로는 기준치인 5$\times$1-$^{-4}$ $\mu$Ci/ml이하로 유지시킬 수 없었다. 따라서 기존의 시설변경이 불가피하며 그 방안으로 사용후 핵연료 저장조에서의 양이온 탈염기 수를 증가시키는 방법이 타당한 것으로 나타났다.

• 한국산업보건학회지
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• 제18권1호
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• pp.32-40
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• 2008

Methyl bromide has been used as a representative fumigant for quarantine, and several poisoning cases have occurred recently by this chemical in Korea. The purpose of this study is to evaluate workers' exposures to airborne methyl bromide in the importing and exporting plant products quarantine companies. Air samples were collected 400/200 mg Anasorb 747TM and were analyzed by gas chromatograph /flame ionization detector according to the Occupational Safety and Health Agency (OSHA) Method PV2040. Geometric mean (GM) and arithmetic mean (AM) of total 27 workers' exposure concentrations to airborne methyl bromide were 1.12 ppm and 0.24 ppm, respectively. Two exposures(12.1 ppm and 12 ppm as 8hr-TWA) of total 27 workers' exposures exceeded the Korean standard (5 ppm) of Ministry Labor, while 4 exposures (15%) exceeded the Threshold Limit Value (TLV) (1 ppm) of American Conference of Governmental Industrial Hygienists (ACGIH). Seven samples (11%) of total 63 short-term air samples exceeded the OSHA Permissible Exposure Limit (PEL) 20 ppm (Ceiling). The opening (management) task in wood fumigation by tent showed the highest short-term exposure concentrations (AM: 18.6 ppm, GM: 0.58 ppm, maximum: 340.7 ppm). The maximum level in treatment task of the same process was 2.01 ppm. Methyl bromide concentrations in opening operation was significantly higher than that in treatment operation (p<0.05). In conclusion, the GM of workers' 8hr-TWA exposures to airborne methyl chloride in the importing/exporting plant quarantine industry was estimated below the ACGIH TLV (1 ppm). However, opening task in the fumigation of wood being covered with tent or fumigation of pant products in container showed the levels exceeding ACGIH TLV (1 ppm), and opening task in the fumigation of wood being covered with tent showed the level exceeding the Korean standard of Ministry of Labor (5 ppm).

• 한국산업보건학회지
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• 제7권2호
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• pp.289-297
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• 1997

Work-related low back pain(below LBP) is one of the major cause of morbidity, disability, limitation of activity and economic loss. Therefore the work-related LBP is one of the major issue in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the effective control programs of work-related LBP. The subjects were male workers employed at the welding and metal factory. The data was collected by self-reported questionnaire, interview and checking abdomen muscular and grasping power for two days on October, 1993. The contents of questionnaire were as follow: the experience of LBP, general characteristics, physical characteristics, employment status, type of work and working environment. The number of cases was 104 with a history of work-related LBP, so the prevalence of work-related LBP was 35.0%, and the number of controls was 140 without any history of LBP. As a result, marital status, educational level, abdomen muscular power, tenure, category of job, satisfaction of job, working posture, satisfaction for table and chair and lifting materials showed a statistical significance between the case and control groups. 284 Lifting jobs were quantified by NIOSH lifting equation method and ergonomic computer modelling methods. There were no significant differences in the action limit and disc compression force between group with LBP and without LBP. But in the lifting frequency and cumulative disc compression force there were significant differences. Therefore work-related LBP should be prevented by the ergonomic and environmental control.

• Advances in environmental research
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• 제6권4호
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• pp.241-254
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• 2017

This study was conducted to investigate the levels of heavy metals in twelve species of vegetables and assessment of health risk. Samples were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd and Pb in vegetables species were 0.37-5.4, 0.03-17, 0.35-45, 0.01-2.6, 0.001-2.2, and 0.04-8.8 [mg/kg, fresh weight (fw)], respectively. The concentrations of As, Cd and Pb in most vegetable species exceeded the maximum permissible levels, indicating unsafe for human consumption. Health risks associated with the intake of these metals were evaluated in terms of estimated daily intake (EDI), and carcinogenic and non-carcinogenic risks by target hazard quotient (THQ). Total THQ of the studied metals from most of the vegetables species were higher than 1, indicated that these types of vegetables might pose health risk due to metal exposure. The target carcinogenic risk (TR) for As ranged from 0.03 to 0.48 and 0.0004 to 0.025 for Pb which were higher than the USEPA acceptable risk limit (0.000001) indicating that the inhabitants consuming these vegetables are exposed to As and Pb with a lifetime cancer risk. The findings of this study reveal the health risks associated with the consumption of heavy metals through the intake of selected vegetables in adult population of Bangladesh.

• 한국산업보건학회지
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• 제16권2호
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• pp.161-171
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• 2006

The objectives of this study were to ergonomically evaluate varying tasks performed in a general hospital and to propose their improving measures based on the evaluation results. The tasks found in the hospital were largely classified into two groups of manual materials handling and awkward posture related tasks. Ergonomic tools of NLE, 3-D SSPP and RULA were used for evaluating workload of the tasks. The major findings are: 1) L5/S1 compressive force of patient transferring by one person exceeded the maximum permissible limit(6,400N) by NIOSH. The L5/S1 compressive forces for most of the patient transferring tasks by 2-4 persons were larger than the action limit (3,400N), and the tasks by five persons were analyzed to be safe in the view of L5/S1 compressive force; 2) patient repositioning tasks by 2-3 persons were hazardous on the basis of L5/S1 compressive force, while most of the tasks by 4-5 persons were safe; 3) many tasks performed in wards were found to be stressful, most of which resulted from improper heights of their working tables or working points. Of varying tasks in general hospitals, patient transferring was the most stressful. Based on the results of this study and high prevalence of musculoskeletal disorders from other studies, it is recommended that the ergonomics program be introduced and enforced for doing improving activities systematically

• Ocean and Polar Research
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• 제28권4호
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• pp.385-393
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• 2006

Screening performance of the existing intake screens (drum and travelling screen) on mass impingement of marine animals, a euphausiid, Euphausia pacifica and a scyphozoan medusae, Aurelia aurita that have often clogged intake screens of the Uljin Nuclear Power Plant, was tested. The maximum tolerable densities of marine animals in the inflowing seawater upon the screen were estimated with two different approaches. First the maximum density of jellyfish was calculated from (1) passing amount of seawater per unit time through the screens and (2) the covered area of animals on the screens clogged. The maximum density of krill tolerable in the drum screen was cited from a simulated record of Uljin NPP, then those in the travelling screens were also calculated using the data of drum screen and ratio of seawater amount passing through the screens under the condition of 0.5m water column (W.C.) of the differential pressure (AP) produced by screens, an established permissible limit of ${\Delta}P$. Secondly, the screening performances were also tested by hydrodynamic measurements with various screen models in a circulating water channel equipped with a speed-controlling pump and a differential pressure gauge. From the first approach, the maximum tolerable densities of drum and travelling screen were calculated as 2.0 and $1.5ind/m^3$ for the Jellyfish and 900 and $680ind./m^3$ for the euphausiid, respectively. These densities estimated from the second approach were 2.1 and $0.8ind/m^3$ for the jellyfish and 1059 and $504ind/m^3$ for the euphausiid, respectively. These estimates were compared with the data from historic clogging events to evaluate the practical performance of these intake screens. The comparisons suggest a newly improved intake-screen of which performance should be at least seven times (approximately) better than the existing ones ior the krill and 3.2 times for the jellyfish, respectively, for preventing mass impingement, and for maintaining the condition of the differential pressure between the screens below 0.3 m W.C.

• 공업화학
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• 제29권4호
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• pp.413-418
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• 2018

붕산, 5붕산암모늄, 붕산/5붕산암모늄 첨가제로 처리한 편백목재 시험편의 연소가스 발생에 관한 시험을 하였다. 4 wt%의 붕소 화합물 수용액으로 각각 편백목재 시험편에 붓으로 3회 칠하였다. 실온에서 건조시킨 후, 콘칼로리미터(ISO 5660-1)를 이용하여 연소가스를 분석하였다. 그 결과, 붕소 화합물로 처리한 시험편의 두 번째_최대산소 소모율은 0.1067~0.1246 g/s로서 공시험편보다 5.3~18.9% 감소했다. 붕산, 5붕산암모늄으로 처리한 시험편의 비소화면적은 2.0~19.0% 감소하였다. 그러나, 붕산/5붕산암모늄으로 처리된 경우 비감쇠면적이 공시험편보다 21.2% 증가하였다. 붕소 화합물로 처리한 시험편의 최대일산화탄소 농도는 0~25% 감소되었다. 이것은 직업안전위생관리국(Occupational Safety and Health Administration, OSHA) 허용기준의 1.6~2.2배의 치명적인 독성을 발생하는 것으로 측정되었다. 붕소화합물은 일산화탄소 감소에는 효과적이었으나 OSHA의 허용기준에는 미치지 못하였다. 붕소화합물은 편백나무의 연소성을 두 번째_최대산소 소모율에 대하여 5.3~18.9%, 최대일산화탄소 발생에 대하여 0~25% 억제하였다.

• Natural Product Sciences
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• 제26권1호
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• pp.50-58
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• 2020

The study was conducted for quantitive determination of macronutrients, micronutrients and heavy metals present in Spilanthes acmella Hutch and Dalz, a traditionally used important medicinal plant. The results illustrated the presence of substantial amounts of essential nutrient elements in different parts of the plant. K and Mg were detected in the range between 36.35 ± 1.01 to 67.78 ± 1.33 g/kg and 2.17 ± 0.13 to 7.02 ± 0.84 g/kg of DWS respectively. While the essential micronutrients Fe, Na, Mn, Zn and Cu were detected in the range between 62.62 ± 12.72 to 856.95 ± 76.61 mg/kg, 365.47 ± 23.84 to 633.03 ± 38.12 mg/kg, 51.66 ± 7.77 to 186.33 ± 13.92 mg/kg, 41.87 ± 2.85 to 53.89 ± 3.79 mg/kg and 18.49 ± 2.07 to 48.71 ± 4.89 mg/kg of DWS respectively. Besides, heavy metals (Cd, Ni and Pb) detected in some of the plant samples were beyond the maximum permissible limit (MPL) of FAO/WHO for herbal medicines. The concentrations of the essential nutrient elements except zinc were significantly different in different parts of the plant (p < 0.001). Further variation in the concentrations of the elements in the plant was observed with respect to seasonal changes and geographical conditions. Nevertheless the findings corroborate ethnomedicinal significance of the plant and signify the possibilibity of utilizing its standardized products for preparation of food supplements as well as multidimensional therapeutic herbal medicines.

• 한국축산식품학회지
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• 제37권1호
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• pp.79-86
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• 2017

Aflatoxin $M_1$ ($AFM_1$) after its bioconversion from aflatoxin $B_1$ in animal liver becomes the part of milk while heavy metals get entry into milk and milk products during handling in the supply chain. Aflatoxin $M_1$ and heavy metals being toxic compounds are needed to be monitored continuously to avoid any ailments among consumers of foods contaminated with such toxicants. Thirteen commercially available infant formula milk (IFM) brands available in Pakistani markets were analyzed for the quantitative determination of $AFM_1$ and heavy metals through ELISA and atomic absorption spectrophotometer, respectively. $AFM_1$ was found positive in 53.84% samples while 30.76% samples were found exceeding the maximum EU limit i.e. $0.025 {\mu}g/kg$ for $AFM_1$ in IFM. Heavy metals lead (Pb) and cadmium (Cd) were found below the detection limits in any of the sample, whereas the concentrations of iron (Fe), zinc (Zn) and nickel (Ni) ranged between 45.40-97.10, 29.72-113.50 and <$0.001-50.90 {\mu}g/kg$, respectively. The concentration of Fe in all the tested brands was found in normal ranges while the concentrations of Zn and Ni were found exceeding the standard norms. Elevated levels of $AFM_1$, Zn and Ni in some of the tested IFM brands indicated that a diet completely based on these IFM brands might pose sever health implications in the most vulnerable community i.e., infants.

• 한국식품과학회지
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• 제37권4호
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• pp.519-524
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• 2005

국내산 소금과 수입산 소금의 무기질 및 중금속 함량의 차이와 이들 소금이 새우젓의 무기질 및 중금속 함량에 미치는 영향을 파악하였으며, 실제 시판되고 있는 새우젓을 산지별로 구입하여 무기질 및 중금속 함량을 분석하였다. 국산 천일염과 그것으로 제조한 새우젓은 중국산에 비해 Cu, K, Mg의 함량이 많았으며, 중국산 천일염과 그것으로 제조한 새우젓은 Mn, Na함량이 높은 것으로 나타났다. 그러나 시판새우젓에서는 산지에 따른 무기질의 차이가 나타나지 않았다. 중금속을 분석한 결과 시판 소금은 Pb, Hg 및 As는 검출되지 않았으나, Cd는 식품공전의 규정(<0.5ppm) 이하인 0.07-0.30ppm의 함량으로 검출되었다. 20 종의 시판 새우젓의 경우, Cd가 0.1 ppm(ND-0.5 ppm)의 함량으로 검출되었으며, 실험실 제조 새우젓의 경우, Pb이 0.3ppm(ND-0.8ppm)의 함량으로 검출되었으며, 다른 중금속(As, Hg, and Ni)은 검출되지 않았다.