수산자원보호구역의 유기물과 중금속 분포특성을 파악하기 위하여 2017년 2월 남서해연안 5개 수산자원보호구역(가막만, 여자 만, 득량만, 완도연안, 영광연안) 54개 정점에서 표층 퇴적물을 채취하여 입도, 강열감량(IL), 화학적산소요구량(COD), 산휘발성황화물(AVS) 및 중금속(As, Cd, Cr, Cu, Fe, Hg, Pb, Zn)을 분석하였다. 평균입도(Mz)는 평균 7.4±0.1Ø 였으며, 주로 세립한 니(mud) 퇴적물로 구성되어 있었다. IL, COD와 AVS의 평균농도는 각각 4.63±0.96 %, 13.0±3.1 mgO2/g·dry, 0.092±0.124 mgS/g·dry 였으며, 영광연안이 다른 보호구역에 비해 낮았다. 중금속의 평균농도는 각각 As 7.5±0.9 mg/kg, Cd 0.04±0.02 mg/kg, Cr 70.2±9.7 mg/kg, Cu 15.3±2.8 mg/kg, Fe 3.3±0.5 %, Hg 0.014±0.003 mg/kg, Pb 25.0±6.0 mg/kg, Zn 99±14 mg/kg 였으며, 보호구역내 대부분 만 안쪽에서 높고 만 외측 및 외측연안에서 낮은 특성을 보였다. 퇴적물기준 (sediment quality guidelines, SQGs), 오염부하량지수(pollution load index, PLI), 생태계위해도지수(ecological risk index, ERI)를 사용하여 퇴적물 중 금속 오염도를 평가한 결과, 남서해연안 수산자원보호구역 퇴적물은 수산생물 및 저서생물에 영향을 주지 않는 안전한 중금속 농도를 유지 하고 있었다.

본 연구는 2018년 경기도내 대형마트, 온라인에서 유통 중인 해조류 및 해조류가공품 80건을 대상으로 중금속 4종(납, 카드뮴, 비소, 수은)의 오염도를 모니터링하고, 해조류 섭취에 따른 위해도를 평가하였다. 현재 해조류에 설정된 중금속 기준은 납의 경우 미역(미역귀 포함)에만 0.5 mg/kg 이하로 설정되어 있으며, 카드뮴은 김(조미김 포함)과 미역(미역귀 포함)에 0.3 mg/kg 이하로 설정되어있다. 검사 결과 기준이 설정된 제품은 모두 기준치 이내로 적합한 것으로 나타났다. 중금속 중 특히 비소의 경우 대부 분의 해조류에서 대체로 높은 함량을 나타내었으며, 유기비소와 달리 독성이 강한 것으로 알려진 무기비소의 함량이 다소 높은 톳과 모자반을 함유한 가공식품에 무기비소 기준을 신설하여 2018년부터 시행중에 있다. 본 연구에서 진행된 톳 제품은 시행일 전에 제조되어 기준 적용 대상은 아니었지만, 건조 톳 8건 중 4건은 수산물, 4건은 기타 수산물가공품으로 분류되어 있어 명확한 유형 분류 기준이 먼저 필요할 것이다. 노출량에 따른 위해도는 안전한 수준으로 나타났으나, 현재 우리나라에서 섭취하는 해조류의 종류에 비해 중금속 기준이 설정이 되어있는 해조류는 미비하기 때문에, 본 연구 결과는 향후 해조류의 중금속 관리 기준 설정을 위한 기초자료로 활용할 수 있을 것 이다.

Information and communication technologies are developing rapidly as IC chip size becomes smaller and information processing becomes faster. With this development, digital circuit technology is being widely applied to mobile phones, wireless LANs, mobile terminals, and digital communications, in which high frequency range of GHz is used. In highdensity electronic circuits, issues of noise and EMC(Electro-Magnetic Compatibility) arising from cross talk between interconnects or devices should be solved. In this study, sheet-type electromagnetic wave absorbers that cause electromagnetic wave attenuation are fabricated using composites based on soft magnetic metal powder and silicon rubber to solve the problem of electromagnetic waves generated in wireless communication products operating at the frequency range of 2.4 GHz. Sendust(Fe-Si-Al) and carbonyl iron(Fe-C) were used as soft magnetic metals, and their concentrations and sheet thicknesses were varied. Using soft magnetic metal powder, a sheet is fabricated to exhibit maximum electromagnetic attenuation in the target frequency band, and a value of 34.2dB(99.9 % absorption) is achieved at the target frequency.

This study aims to evaluate the concentration of biomarkers for heavy metals and volatile organic compounds (VOCs) for the residents living in the Gwangyang industrial complex to compare with residents in the residential area as a control. A total of 810 healthy adults participated in this study, and their urinary and blood samples were analyzed for metals, including As, Pb, Cd, or Hg, and VOC compounds. All study participants also completed questionnaire surveys to collect more detailed information on personal lifestyles, dietary and drinking habits, residential housings types, and their health conditions. The geometric means of urinary levels of Cd were 1.06 g/g creatinine for those living in the vicinity of Gwangyang industrial complex and 1.41 g/g creatinine for those in residential areas (p<0.05). Furthermore, urinary mean levels of Hg were 1.39 μg/g creatinine in the industrial area and 1.23 μg/g creatinine in the control area, respectively. The concentrations of individual VOCs in blood were significantly different between the two population groups. Therefore, urinary levels of Cd and Hg were significantly higher in the local residents compared to the Gwangyang industrial areas. A further study is needed to identify adverse health effects due to environmental exposures to heavy metals, VOCs, and other pollutants in the Gwangyang industrial complex areas in the future.

Heavy metals in stream water and sediments around industrial complex were studied in order to assess the contamination and to identify the potential source of metals. High variability has been observed for both dissolved and particulate phases in stream water with coefficient of variation (CV) ranging from 1.3 to 2.8. The highest metal concentrations in both phases were observed in Gunja for Ni and Cu, in Jungwang for Zn and Pb and in Shiheung for Cd, respectively. These results indicate that the different metal sources could be existing. The concentrations of the heavy metals in sediments decreased in the order of Cu>Zn>Pb>Cr>Ni>As>Cd>Hg, with mean of 2,549, 1,742, 808, 539, 163, 17.1, 5.8, 0.07 mg kg-1, respectively. Mean of metal concentrations (except for As) in sediments showed the highest values at Shiheung stream comparing with other streams. In sediments, the percent exceedance of class II grade that metal may potentially harmful impact on benthic organism for Cr, Ni, Cu, Zn, Cd, Pb was about 57%, 62%, 84%, 60%, 68%, 81% for all stream sediments, respectively. Sediments were classified as heavily to extremely polluted for Cu and Cd, heavily polluted for Zn and Pb, based on the calculation of Igeo value. About 59% and 35% of sediments were in the categories of “poor” and “very poor” pollution status for heavy metals. Given the high metal concentrations, industrial wastes and effluents, having high concentrations of most metals originated from the manufacture and use of metal products in this region, might be discharged into the stream through sewer outlet. The streams receive significant amounts of industrial waste from the industrial facilities which is characterized by light industrial complexes of approximately 17,000 facilities. Thus, the transport of metal loads through streams is an important pathway for metal pollution in Shihwa Lake.

본 연구는 인삼과 산양삼의 부위별 중금속 분포양상을 조사하여 중금속 식이노출 저감화 방안을 모색하고자 하였다. 인삼과 산양삼은 지역별 배분을 통해 각각 14개 지역 및 5개 지역에서 시료를 채취하였으며, 각 부위별 중량 및 중금속 함량을 분석하였다. 중금속 분석을 위해 microwave 장치를 이용해 전처리한 후 납, 카드뮴 및 비소는 ICP-MS로 측정하고 알루미늄은 ICP를 이용한 분석법을 확립하였다. 인삼의 겉껍질은 전체의 16.2% 중량비를 차지하였으며, 산양삼의 겉껍질 및 잔뿌리는 각각 전체의 21.8%, 16.8%의 중량비를 차지하였다. 각 부위별 중량비와 중금속 농도를 고려하여 각 부위별 중금속 분포도를 산출하였다. 인삼 및 산양삼의 겉껍질은 전체에 차지하는 중량비에 비해 높은 중금속 함유량을 보이고 있었으며, 인삼의 경우 납의 40.3%, 카드뮴 25.9%, 비소 47.6%, 알루미늄 89.9%가 겉껍질에 잔존하고 있었으며 산양삼의 경우 납 27.2%, 카드뮴 28.2%, 비소 48.3%, 알루미늄 56.8%가 겉껍질에 존재하였다. 알루미늄을 제외하고 산양삼의 잔뿌리내 중금속 분포량은 겉껍질과 유의적 차이가 없었다. 따라서, 인삼 및 산양삼의 겉껍질을 벗기고 섭취 한다면 중금속 식이노출량을 크게 줄일 수 있음을 확인하였다.

The physical treatment such as chemical precipitation or adsorption was usually added after biological treatment in wastewater treatment process since it was enforced to reduce the concentration of phosphate for wastewater effluent to 0.2 mg/L as P which was well known as one of main nutrient causing eutrophication in waterbody. Therefore, the new material functioned for both adsorption and disinfection was prepared with Fe and Cu, and TiO2, respectively, by changing the ratio of concentration referred to tri-metal (TM). According to SEM-EDS, TiO2 was 30~40% composition for any TM regardless of any synthesis condition. However, the ratio of composition for Fe and Cu was dependent on the initial Fe and Cu concentration, respectively. The removal efficiency of phosphate was obtained to 15% at low initial concentration and the maximum uptake (Q) was calculated to ~11 mg/g through Langmuir isotherm model using TM1 which was synthesized at 1000 mg/L, 1000 mg/L, and 2 g (10 g/L) for Fe(NO3)3, Cu(NO3)2, TiO2, respectively. In disinfection test, the efficiency of virus removal using TM was increased with increase of dosage of TM and can be reached 98% at 0.2 g.

The recent development of information and communication technologies brings new changes to automobile traffic systems. The most typical example is the advancement of dedicated short range communication(DSRC). DSRC mainly consists of an intelligent transportation system(ITS), an electronic toll collection system(ETCS) and an advanced traveler information system(ATIS). These wireless communications often cause unnecessary electromagnetic waves, and these electromagnetic waves, in turn, cause frequent system malfunction. To solve this problem, an absorber of electromagnetic waves is suggested. In this research, various materials, such as powdered metal and iron oxides, are used to test the possibility for an effective absorption of the unnecessary electromagnetic waves. The various metal powders are made into a thin sheet form by compositing through processing. The electromagnetic characteristics(complex permittivity, complex permeability) of the fabricated sheet are measured. As a result, we achieve –6.5 dB at 940 MHz(77.6 % absorption rate) with a 1.0 mm-thickness electromagnet wave absorber, and –9.5 dB at 940 MHz(88.8 % absorption rate) with a 2.0 mm-thickness absorber.

가속화되는 산업화로 인해 중금속 이온의 침출이 환경문제로 떠오르고 있다. 수질 정화를 위한 몇 가지 방법 중 기능성 고분자 섬유를 이용한 흡착은 효율적이며 경제적이라는 장점이 있다. 특히, 폴리아크릴로나이트릴(polyacrylonitrile, PAN)은 금속 이온을 흡착할 수 있는 작용기가 많아 관심을 끌고 있다. PAN은 쉽게 전기방사를 통해 고분자 나노 섬유화될 수 있으며 높은 표면적을 가질 수 있다. 본 총설에서 다룰 복합 PAN 섬유는 폐수 처리를 위한 또 다른 유형의 고분자이다.