This study analyzed the total number of 19,636 patients and radiation technologists, 11,433 of male and 8,203 of female by examined body parts, age, types of detectors, the using contrast enhancement and working condition of the technologists, regular staffs or rotation-duty staffs, based on the K-DOS program distributed by FDA with the DLP value of diagnostic evaluation. The result shows that the effective radiation dose was 0.7mSv~41.7mSv for each region and male patients had more radiation exposure than females. And the amount of exposure was also affected by the types and the method of detectors. Furthermore, the regular staffs took the role of helping the patient to get reduced amount of radiation exposure than rotation duty-staffs. Computed tomography (CT) use has increased dramatically over the past several decades. In this reason, to support the patients and the workers’ health in the field, the hospitals should apply specialized regular working radiation technologist system and manufacturing companies of those CTs should develop low medical radiation exposure devices.

Di-n-butyl phthalate (DBP), diisononyl phthalate (DINP) and di-(2-ethylhexyl) adipate (DEHA) are ubiquitously distributed chemicals that are widely used as plasticizers and also found at low levels in foods. The aims of this study were to determine whether perinatal exposure to DBP, DINP and DEHA could alter normal patterns of neonatal development. Dams were provided with pulverized soy-free diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day 15 to postnatal day 21. Exposure to the high doses of DBP, DINP and DEHA during gestational period significantly decreased food consumption and body weight gain of dams. These chemicals reduced neonatal body weight as well as that of the after maturation. Also, exposure to DINP of all the doses used and the higher doses (2,400 and 12,000 ppm) of DEHA decreased AGD at PND 1 in male neonates, though that to DBP did not affect AGD in males. In female neonates, an increase in AGD was observed in DBP- and DINP-exposed animals at the highest doses. Moreover, these chemicals affected survival rate of pups at PND 5, and delayed onset of eye opening in all chemical-exposed groups at PND 17. These results suggest that perinatal exposure to these chemicals may affect the normal development and / or growth of offspring.

The exposed strain of C. riparius treated with di (ethyl- hexyl)-phthalate (DEHP) did not result in a consistent relationship between mortality or sex ratio and chemical concentrations. And after treating with DEHP, the emergent female from the exposed st

The effect of CO2 concentration (500, 3,000, 6,000㎕/ℓ) on the mycelial growth and fruit body primordium formation of Ganoderma lucidum on nutrient agar medium was examined. Optimum CO2 concentration for vegetative growth was above 3,000㎕/ℓ. Fruit body initiation was accelerated at higher than 3,000㎕/ℓCO2 exposure but the maximum number and size of primordia, and primordium color were not influenced by CO2 concentrations. Whereas each atypical fruiting structure forming stock culture showed different fruiting time under each concentration of CO2 exposure.

본 연구는 자동노출제어 (AEC; Automatic Exposure Control)를 이용한 복부 일반 X선 검사에서 체질량지수 (BMI; Body Mass Index)가 입사표면공기커마 (ESAK; Entrance Surface Air Kerma)에 미치는 영향에 대해 알아보았다. 연구방법은 AEC를 이용하여 복부 일반 X선 검사를 시행 받은 321명을 대상으로 키, 몸무게, BMI와 ESAK의 관계 및 BMI범주 (Underweight, Normal, Overweight, Obese 1, Obese 2)에 따른 평균 ESAK값을 비교하였다. 연구의 결과 몸무게 (R2=0.777, p<.001)와 BMI (R2=0.835, p<.001)는 ESAK와 양의 상관관계가 있었던 반면, 키 (R2=0.075, p<.001)와 BMI는 뚜렷한 상관관계를 확인할 수 없었다. BMI범주에 대한 평균 ESAK는 통계적으로 유의한 차이를 보였으며, 사후분석을 통해 유의수준 0.05에 대해 5개의 부집단이 존재하여 모든 BMI범주 간 ESAK값의 차이가 있는 것을 알 수 있었다. 또한, 인접한 BMI간 ESAK값 증가폭이 Underweight에서 Obese 2로 갈수록 점차 늘어나 BMI가 증가할수록 피폭선량이 급격하게 증가되는 것을 알 수 있었다. 따라서 복부 일반 X선 검사에서 AEC를 사용할 경우 BMI가 증가함에 따라 과도한 선량이 조사될 수 있음을 인식하고 검사조건을 고정하여 촬영하는 등의 노력을 통한 선량저감화가 필요할 것으로 판단된다.

유방촬영의 경우 대부분 양쪽 유방에 대해 연속촬영이 시행되고 있으며, 검사 시 규정하고 있는 3 mGy의 평균유선 선량 보다 낮다 하더라도 추가 검사 및 연속촬영으로 인해 실제는 더 많은 선량을 받게 된다. 또한 검사 유방 외에 주변장기선량에 대해 인지하기 어렵다. 이에 본 연구는 유방영상시스템에서 수학적 모의피폭체를 이용하여 필터의 두께 변화(25, 30, 50 μm)에 따른 주변장기 선량분포와 검사측 유방을 기준으로 한 상대적 흡수선량률을 알아보았다. 그 결과 검사 반대 유방의 선량이 검사 유방을 기준으로 79.26∼86.31%정도로 많은 영향이 미치는 것으로 나타났으며, Mo/Mo, W/Rh 조합에서 실제 사용되고 있는 필터 두께 30 μm, 50 μm 보다 얇은 25 μm를 사용했을 때 검사 반대 유방과 주변장기의 상대적 흡수선량률이 낮게 나타났다.