• 한국안전학회지
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• 제24권2호
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• pp.100-104
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• 2009

In this study, the space gamma dose rates in the apartments structured with concrete were measured in accordance with construction year. In addition, the environmental radiation rates coming from the subway platforms and the road tunnels were analyzed in the equivalent dose by multiplying the absorbed dose with the radiation weighting factors. The space gamma dose rates measured in apartments were higher than those of outdoor which was $0.08{\sim}0.11uSv/h$ in the natural conditions. Especially, the older construction year is, the higher becomes space gamma dose rate. The average gamma dose rates in the subway platforms were measured. In the case of Busan and Daegu subway, the earlier the opening year is, the higher becomes dose rate. However, the dose rates of Seoul subway Lines were high overall, regardless of opening year. Seoul subway Line 6 showed the highest value of 0.21uSv/h. The gamma dose rate in road tunnels was higher than one of the outdoor and increased with opening year like as apartment. In dose rate comparison of the concrete structures with the outdoor, therefore, the space gamma dose rate of indoor is higher than one of the outdoor and the older structures have a higher dose rate.

• 대한임상독성학회지
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• 제9권2호
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• pp.56-60
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• 2011

Purpose: The optimal dose of oximes for use in the treatment of organophosphorus pesticide poisoning has not been conclusively established. In this retrospective study, we assessed the effectiveness of the use of high-dose pralidoxime infusion in treating organophosphorus pesticide poisoning. Methods: From January 1998 to December 2009, 71 patients visited the hospital Emergency Department (ED) as a result of organophosphate pesticide intoxication. All of these patients received an initial bolus of 2 g of pralidoxime as the first step of treatment. Patients who then received continuous infusion of pralidoxime at a dose of 500 mg/hr were entered into study group 1 (low dose), and those treated by continuous infusion of pralidoxime at a dose of 1000 mg/hr were entered into study group 2 (high-dose). Plasma cholinesterase activities for each patient were evaluated at ED arrival and re-evaluated 24 hours after pralidoxime infusion. The effectiveness of the two treatment modalities was gauged by comparing the required duration of mechanical ventilation, time spent in the intensive care unit (ICU) and total time spent in the hospital. Results: The mean duration of mechanical ventilation was $9.98{\pm}6.47$ days for group 1 and $4.39{\pm}6.44$ days for group 2. The respective mean duration of time spent in ICU and the total number of days in the hospital were $16.38{\pm}18.84$ days and $21.87{\pm}20.16$ days for group 1, and $7.83{\pm}9.99$ days and $11.71{\pm}13.53$ days for group 2. Highdose pralidoxime treatment was associated with shorter required durations for mechanical ventilation, ICU and hospital stay. In addition, plasma cholinesterase reactivation rates were higher for those patients receiving high-dose pralidoxime treatment. Conclusion: The results suggest that high-dose pralidoxime treatment has greater efficacy for patients suffering from organophosphorus pesticide poisoning.

• Journal of Radiation Protection and Research
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• 제24권3호
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• pp.123-129
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• 1999

저선량 $\gamma$선 조사한 토마토 2품종, 서광과 하우스모모타로 종자의 발아와 초기생육 및 후속 고선량에 대한 생육효과를 조사하였다. 저선량에 의한 발아와 생육촉진효과는 품종에 따라 달랐다. 발아율의 경우 서광은 모든 저선량 조사구에서 증가되었으나, 하우스모모타로는 오히려 감소되었다. 유묘초장은 저선량 조사에 의해 증가되었으며 두 품종 모두 4 Gy와 8 Gy 조사구에서 가장 효과적이었다. 생육 2개월 후 서광의 초장은 억제되었으나 생체중은 4 Gy와 2 Gy에서 증가되었고, 하우스모모타로의 초장은 12 Gy와 20 Gy에서, 생체중은 20 Gy와 4 Gy에서 가장 높은 증가효과를 보였다. 토마토 식물체의 고선량 피폭에 의한 생육장해는 사전 저선량 조사에 의해 감소되었는데 서광의 경우 2 Gy와 8 Gy 조사구에서 저항성이 높았으며 하우스모모타로의 경우 모든 저선량 조사구에서 저항성 효과가 나타났으며 특히 2 Gy와 12 Gy 조사구에서 높았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.126-126
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• 2009

X-ray high-voltage generator is the most important part that can decide the radiation exposure dose affecting a patient or operator according to the characteristic. If decrease of X-ray radiation exposure dose and output characteristic of high-voltage generator is unstable, a patient or operator must be exposed to more radiation. This study measures and analyzes the exposure dose reproducibility and output characteristic according to a change of tube current on the various rectification methods of diagnostic X-ray equipment. It can find that quality bastardize and output is increased if voltage of X-ray tube is increased. Exposure dose reproducibility according to output of X-ray equipment is extremely excellent in inverter type, and is stable in order of following three-phase, a single-phase and condenser method. This study can find that the reply incidence of high-voltage generator is generated due to difference in rectification method, noise occurs in X-ray due to that, quality of an image is decreased due to that, and medical diagnosis can be failed due to that.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1220-1224
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• 2003

In this paper, we measured the radiation dose of a fuel handling machine of the CANDU type Wolsong nuclear reactor directly during operation, in spite of the high radiation level. In this paper we will describe the sensor development, measurement techniques, and results of our study. For this study, we used specially developed semiconductor sensors and matching dosimetry techniques for the mixed radiation field. MOSFET dosimeters with a thin oxide, that are tuned to a high dose, were used to measure the ionizing radiation dose. Silicon diode dosimeters with an optimum area to thickness ratio were used for the radiation damage measurements. The sensors are able to distinguish neutrons from gamma/X-rays. To measure the radiation dose, electronic sensor modules were installed on two locations of the fuel handling machine. The measurements were performed throughout one reactor maintenance cycle. The resultant annual cumulative dose of gamma/X-rays on the two spots of the fuel handling machine were 18.47 Mrad and 76.50 Mrad, and those of the neutrons were 17.51 krad and 60.67 krad. The measured radiation level is high enough to degrade certain cable insulation materials that may result in electrical insulation failure.

• Toxicological Research
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• 제25권2호
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• pp.79-84
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• 2009

Cerium oxide nanoparticles (size: 30 nm) were prepared by the supercritical synthesis method, Acute oral toxicity and tissue distribution of the nanoparticles were evaluated by a single administration in rats. Oral administration of the nanoparticles to the rats did not lead to death when the animals were treated by a dose of 5 g/kg (high dose) as well as 100 mg/kg (low dose). Abnormal clinical signs, changes in serum biochemistry and hematology were not observed in high-dose treated group compared to the vehicle control group. Lesions in liver, lung and kidney were not observed in high-dose treated group by histopathological examination. Tissue distribution analysis in liver, kidney, spleen, lung, testis and brain was performed on day 1, day 7 and day 14 after treatment. The average values of the accumulated cerium oxide nanoparticles were elevated in all tissues but statistical significance was only shown in lung. Low levels of tissue distributions after a single oral administration seem to be the low bioavailability of the nanoparticles.

• Clinical and Experimental Reproductive Medicine
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• 제39권4호
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• pp.144-152
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• 2012

Objective: Concerns are growing about the decrease in male reproductive health. Caffeine is one of the popular nutrients that has been implicated as a risk factor for infertility. In the present study, we examined whether in utero and lactational exposure to caffeine affects the reproductive function of the offspring of rats. Methods: Pregnant rats received caffeine via drinking water during gestation (26 and 45 mg/kg) and lactation (25 and 35 mg/kg). Body and reproductive organ weight, seminiferous tubule diameter, germinal epithelium height, sperm parameters, fertility rate, number of implantations, and testosterone level of the offspring were assessed from birth to adulthood. Results: Significant dose-related decreases were observed in the body and reproductive organ weight, seminiferous tubule diameter, and germinal epithelium height of the offspring. Sperm density had declined significantly in offspring of the low-dose and high-dose groups, by 8.81% and 19.97%, respectively, by postnatal day 150. The number of viable fetuses had decreased significantly in females mated with male offspring of the high-dose group at postnatal days 60, 90, 120, and 150. There were also significant reductions in testosterone levels of high-dose group offspring from birth to postnatal day 150. Conclusion: It is concluded that maternal caffeine consumption impairs gonadal development and has long-term adverse effects on the reproductive efficiency of male offspring rats.

• Toxicological Research
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• 제18권3호
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• pp.285-292
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• 2002

The repeated toxicity of Gleditschia-saponin produced and provided by S.S. Bio-Tech Bench Co. was evaluated in Sprague-Dawley rats. Gleditschia-saponin was administered to rats by oral route at dose levels of high (180 mg/kg/day), medium (90 mg/kg/day) and low (45 mg/kg/day) once a day for 14 days. Saline was administered to another group of rats as control. Each group was consisted of 5 male and female rats. There were no dose-related changes in clinical findings, food and water consumption, organ weights, urine analysis, biochemical examination and hematological findings in all groups of animals treated with Gleditschia.- saponin, except body weights. Body weighs in male and female rats were increased significantly (p < 0.05) from day 4 to 14 in low, middle and high dose groups than control group. Body weight in high dose group was increased higher than control or low, middle dose groups on day 14. Gross and histopathological findings revealed no evidence of specific toxicity to Gleditschia.-saponin. Therefore, it was concluded that Gleditschia-saponin had no toxic or side effects in Sprague-Dawley rats in an repeated oral toxicity tests.

• Toxicological Research
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• 제6권2호
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• pp.131-142
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• 1990

The selective toxicity of lead was tested in central catecholaminergic nervous system of postnatally lead exposed rats. Three groups of animals were prepared; 1) rats exposed to low dose of lead (0.05%PbAc); 2) rats exposed to high dose of lead(0.2%PbAc); 3) age-matched normal control rats. At2, 4, 6 and 8 weeks of age brain and body weight gain, and lead concentrations in brain tissues were measured. At the same ages tyrosine hydroxylase and Na-K ATPase activities were measured in the 4 brain areas of each animal. Body weight gain was decreased after 6 weeks of age in rats exposed to high dose of lead. Concentrations of lead in whole brain tissues were increased from 0.37 to 0.83 (ng/mg wet tissue) in these animals. in lead exposed rats, tyrosine hydroxylase activities were higher but Na-K ATPase activities were lower than those of age-matched control animals. Brain areas where tyrosine hydroxylase activities were detected without concomitant changes of Na-K ATPase activities were pons-medulla (2 weeks of age) and telencephalon (6 weeks of age) in rats exposed to low dose of lead, and those in rats exposed to high dose of lead were midbrain (4 and 6 weeks of age). These data indicate that catecholaminergic nervous system in the brain areas described above could selectively be affected by lead.

• 한국안전학회지
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• 제8권4호
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• pp.165-174
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• 1993

For the safety assessment of the demonstration-scale incineration plant for treating the combustible radioactive wastes, radiation doses of a worker and a residential individual were estimated. The demonstration plant showed a good performance of trial-burn tests using non-radioactive tracers with resulting In high mass reduction of around 40 times and very low emmission of dusts through a stack, which promised a high decontamination factor in an order of 10$^{7}$ . Based on the result s obtained from the trial-burns in the process, the estimation of radiation dose for workers and general publics near the plant was made using dose pathway calculation theories. The parametric values for calculation were selected from design and operational results of the process and from more conservative conditions In reference data. The estimated annual doses for workers and residential indivisuals were 3.07 $\times$ 10$^{-4}$ and 4.35 X 10$^{-8}$ $\mu$Sv/y, respectively, which were high enough to operate the process when comparing with the allowable dose limit in the regulation. The dose calculation models were quite applicable with showing an excellent safety for the process.