넙치, Paralichthys olivaceus 수정란의 부화율을 이용하여 중금속(Pb, Cr, As)의 독성 영향을 조사하였다. Pb, Cr, 및 As (0, 10, 100, 500, 1,000, 2,500, 5,000 ppb)에 수정란을 48 h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. 중금속을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Pb, Cr, 및 As에 대해 농도 의존적으로 감소하였으며, 각각 100, 100, 500 ppb 이상의 농도에서 유의한 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Pb, Cr 및 As의 반수영향농도(EC50)를 이용한 독성은 Cr¤As¤Pb 순으로 나타났다. Pb와 As의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타냈으며, Cr에 대한 NOEC는 10 ppb, LOEC는 100 ppb를 나타내었다. 이들 결과로부터 자연생태계 내에서 Pb과 As의 농도는 100 ppb, Cr 농도는 10 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 독성 영향이 나타날 것으로 판단된다. 본 연구 결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 평가방법은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.

The aim of this study was to calculate the health risks which children were exposed to trace metals through several pathways including air, floor dust, wipe and hand wipes in elementary-schools and academies. The samples were collected at children's facilities (50 elementary-schools and 46 academies) in summer (Aug ~ Sept, 2008), winter (Dec 2008 ~ Feb, 2009) and Spring (Mar ~ Apr, 2009) periods. The lifetime Excess Cancer Risks (ECRs) were estimated for carcinogen trace elements such as As, Cd, and Cr. For carcinogens, the Excess Cancer Risk (ECR) was calculated by considering the process of deciding Cancer Potency Factor (CPF) and Age Dependent Adjust Factor (ADAF) of the data of adults. Hazard Quotients (HQs) were estimated for the non-carcinogens trace metals like Cd, Cr, Hg and Pb. The average ECRs for young children were 1×10^-9~1×10^-8 (50%th percentile) level in all facilities. Non-carcinogens did not exceed 0.1 for all subjects in all facilities. For trace metals their risk based on health risk assessment was also observed to be acceptable.

The purpose of this paper was to provide the co-relation lapping conditions of a spectacle metal components. The main elements of lapping conditions were composed of rotation velocity, lapping time, graphite kinds, product quantity and faulty product ratio those were co-related and influenced at each other. The optimal working conditions of lapping were controled the each lapping conditions, mutual relations and reciprocal actions. It was studied the optimal lapping conditions those graphite kinds-rotation velocity-faulty product ratio, rotation velocity-lapping time, rotation velocity-product quantity. Based on these results, the optimal conditions were that the level of graphite was midiμm and rotation velocity was 40∼(60rpm.

In this study, voltammetry system for realizing high sensitivity nano-labeled sensor of detecting heavy metals was designed, and optimal system operating conditions were determined. High precision digital to analog converter (DAC) circuit was designed to control applied unit voltage at working electrode and analog to digital converter (ADC) circuit was designed to measure the current range of at counter electrode. Main control unit (MCU) circuit for controlling voltammetry system with 150 MHz clock speed, main memory circuit for the mathematical operation processing of the measured current value and independent power circuit for analog/digital circuit parts to reduce various noise were designed. From result of voltammetry system operation, oxidation current peaks which are proportional to the concentrations of Zn, Cd and Pb ions were found at each oxidation potential with high precision.

넙치(Paralichthys olivaceus) 수정란의 부화율에 대한 중금속(Cd, Cu, Zn)의 급성독성을 조사하였다. Cd, Cu 및 Zn (0, 10, 100, 500, 1000, 2500, 5000 ppb)에 수정란을 48h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. Cd, Cu 및 Zn을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Cd, Cu 및 Zn에 대해 농도 의존적으로 감소하였으며, 각각 1000, 100, 100 ppb 이상의 농도에서 유의적이 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Cd, Cu 및 Zn의 반수영향농도(EC50)를 이용한 독성은 Zn¤Cu¤Cd 순으로 강한 것으로 나타났으며, 이들 중금속에 대한 EC50는 각각 584, 1015, 1282 ppb를 나타내었다. Cd에 대한 NOEC는 500 ppb를 나타냈고 LOEC는 500 ppb를 나타내었다. Cu와 Zn의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타내었다. NOEC와 LOEC 결과로부터 자연생태계 내에서 Cu와 Zn 농도는 100 ppb, Cd 농도는 500 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 감소할 것으로 판단된다. 본 연구결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 시험은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.

Movement and accumulation of cadmium in male Sprague-Dawley rats, fed with brown rice from nearby Janghang smeltery area were investigated. The rat fed with five different cadmium level diets made with Cdpolluted during 12 weeks. The brown rice-polluted with 0.87 ppm Cd (PBR) was sampled from products in the Janghang smeltery area. Diets of brown rice group were brown rice (BR, 0.002 ppm Cd), each 50% of BR and PBR (BR+PBR 50%, 0.44 ppm Cd) and PBR (PBR 100%, 0.87 ppm Cd). To compare with BR+PBR 50%, the another group diet composed the feed (FE, 0.002 Cd ppm) and each 50% of FE and PBR (FE+PBR 50%, 0.44 ppm Cd). Accumulation of Cd, Zn and Cu in blood, liver and kidney rats was measured by GF-AAS. The weight gain in BR groups and FE groups were different 0.22-0.26 and 1.08-1.26 g/day, respectively. Daily intake cadmium was 10.77 and 22.36 μg/rat in BR+PBR 50% and PBR 100%, and 8.83 μg/rat in FE+PBR 50%. Cadmium contents in diets were higher, and total intake of the heavy metals was more increased on the whole. Weights of liver and kidney in FE+PBR 50% group was 2.64 and 2.27 folds higher than those in BR+PBR 50% group. Cadmium contents in blood were increased with intake of BR diet, but Zn and Cu were decreased with them. In the diet groups with the same Cd concentration, Cd content of FE+PBR 50% was higher 1.27 times than that of BR+PBR 50%. In the diet group of BR, BR+PBR 50%, and PBR 100%, the increase of Cd concentration was significantly different to the increase of Cd content in the livers. In the same condition of Cd concentration, Cd contents were higher in the BR+PBR 50% group. In the diet groups of BR, BR+PBR 50%, and PBR 100%, the increase of Cd content in the kidneys led to the increase of Zn and Cu contents. In the same condition of Cd concentration, the diet group with the addition of BR was shown to be 3.11 times higher than with the addition of FE. In view of the results so far achieved, It was closely related with Cd, Zn, and Cu content.

양식활동이 활발한 반폐쇄적인 내만에서 퇴적물의 지화학적 특성을 파악하기 위하여 2010년 4월 가막만 전역의 19개 정점에서 표층 퇴적물을 채취하여 퇴적물 중의 금속(V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Hg, Pb, As), 비금속(P, Se) 및 악티늄족 중 U원소의 분포특성을 파악하였다. 또한, 퇴적물기준 및 농축계수를 이용하여 금속원소의 오염도를 평가하였다. V, Cr, Fe, Co 및 Ni 등은 석영희석 효과, Cd 및 U은 유기물 희석효과, Mn, Ag, As 및 Se는 만의 북부 및 남부해역 정점들에서 표층퇴적물의 강한 환원환경경하에서 이산화망간 및 황산염이 유기물 분해의 산화제로 이용되면서 화학적 재분배에 의해 농도분포가 결정되어지는 것으로 보여진다. 미국 퇴적물 오염 기준(SQGs)에 의한 오염평가는 As의 경우 만의 중앙부를 제외한 대부분의 정점, Ni은 전 조사정점에서 ERL을 초과하였다. 농축계수(EF)를 이용한 평가는 Ni, Ag, Cd 및 As가 평균 EF가 1을 약간 초과하는 단계를 보였으며, 이외의 성분은 1과 유사하거나 혹은 그 이하 양호한 수준을 나타내었다.