• 한국동물위생학회지
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• 제33권3호
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• pp.299-302
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• 2010

This study was conducted to determine the content of heavy metals in meats available on the Korean markets. Trace metals (Pb, As and Cd) were detected in 4 kinds, 172 samples by inductively coupled plasma-mass spectrometry (ICP-MS). The values of heavy metals in meats were as follows; In beef, mean (minimum~maximum) values of the heavy metals were Pb: 0.075 (0.020~0.190)mg/kg, As: 0.010 (0.001~0.050)mg/kg and Cd: 0.43(0.07~2.11)${\mu}g/kg$. In pork, mean (minimum~maximum) values of the heavy metals were Pb: 0.065 (0.012~0.171)mg/kg, As: 0.004 (ND~0.021)mg/kg and Cd: 0.43(0.08~1.09)${\mu}g/kg$. In chiken, mean (minimum~maximum) values of the heavy metals were Pb: 0.060(0.016~0.211)mg/kg, As: 0.008 (ND~0.042)mg/kg and Cd: 0.42 (0.02~3.80)${\mu}g/kg$. In duck, mean (minimum~maximum) values of the heavy metals were Pb: 0.070 (0.011~0.157)mg/kg, As: 0.005 (0.001~0.011)mg/kg and Cd: 0.87 (0.15~3.75)${\mu}g/kg$. This results will be used as a basic data for the future legislation on the regulation and control of heavy metal in meats.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.51-56
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• 1996

The Bark lignin(alkali- and acid lignin), bark extractives(hot water-and $Na_2SO_3$ extractives) of Quercus acutissima and Pinus densiflora, and flavonoids were used to detect heavy metal adsorption. The adsorption ratio of heavy metals by lignin was assigned for 40 to 50%, but was not dependent on lignin kinds. However, in case of the addition of light metals such as $Ca^{++}$ and $Mg^{++}$ to lignin the adsorption ratio was increased by 20 to 40%, and $Pb^{++}$ was almost completely adsorbed. On hot water extractives, the adsorption ratio was very low because the substrate was water-soluble, so the substrate should be water-insoluble to adsorb the heavy metals. However, the adsorption ratios of $Cd^{++}$ and $Pb^{++}$ on $Na_2SO_3$ extractives were significantly increased, while those of $Zn^{++}$ and $Cu^{++}$, were similar to lignin. When four kinds of heavy metals were treated to $Na_2SO_3$ extractives together, more than 97% of $Pb^{++}$ and $Cu^{++}$ was adsorbed_ and $Zn^{++}$ was more adsorbed by 40%, and $Cd^{++}$ was not changed, comparing with the case that on kind of heavy metal was treated. There were differences between adsorption ratio of the kinds of flavonoids and heavy metals, and the adsorption ratio of heavy metals was assigned to 20 to 45% per 0.1g flavonoid.

• 생태와환경
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• 제41권2호
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• pp.166-173
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• 2008

오염물질을 제거하기 위한 방법 중 하나인 석회 처리를 통하여 청초호 표층 퇴적물에 함유된 중금속의 존재 형태 변화와 환경변화시 수층으로의 용출가능성을 알아보았다. 연속추출 방법을 사용하여 중금속의 화학적 형태를 분석하였고 수층으로의 용출 가능성은 흡착된 형태와 공침된 형태의 합으로 하였다. 석회 처리 전의 청초호 퇴적물에 함유된 Cd과 Cu 및 Zn의 존재형태는 호수 바닥과 같은 혐기성 상태에서 안정된 산화성 형태가 많았으나 석회 처리 시료에서는 이 부분의 비율이 줄어든 반면 용출되기 쉬운 부분인 흡착된 형태와 공침된 형태의 비율이 증가하였다. 이는 석회 첨가로 인한 공극수의 pH상승과 대기중에 노출로 인한 산화에 의한 것으로 판단된다. 수층으로 이동 가능한 부분의 비율은 Cd의 경우 석회함량 15%, Pb은 10%, Cu와 Zn은 20%에서 높게 나타나 중금속으로 오염된 퇴적물의 석회 처리는 퇴적물에 함유된 중금속의 용출을 증가시킬 가능성이 있는 것으로 사료된다.

• Applied Biological Chemistry
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• 제33권2호
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• pp.138-142
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• 1990

담수토양중(湛水土壤中) 살균제(殺菌劑) IBP, 살충제(殺蟲劑) fenitrthion, 살초제(殺草劑) butachlor의 분해(分解)에 미치는 각종중금속(各種重金屬) Cd, Cu, Cr, Ni, Zn의 영향(影響)에 대하여 연구검토(硏究檢討)하였다. 토양중(土壤中) 3농약(農藥)의 분해(分解)는 5종(種)의 중금속첨가(重金屬添加)에 의하여 현저히 억제(抑制)되었으며, 억제(抑制)된 정도(程度)는 butachlor>IBP>fenitrothion순(順)이었다. MPN법에 의하여 계측(計測)한 fenitrothion과 butachlor 분해균(分解菌)의 균수(菌數)은 중금속(重金屬) 첨가(添加) 토양(土壤)에서가 무첨가토양(無添加土壤)에서보다 적었다. 토양중(土壤中) 3농약(農藥)의 분해(分解)에 미치는 영향정도(影響程度)는 중금속(重金屬)의 종류(種類) 및 농도(濃度), 농약(農藥)의 종류(種類)에 따라 현저한 차이(差異)를 나타내어, fenitrothion의 분해(分解)를 Cr>Zn>Cd>Ni>Cu순(順)으로 억제(抑制)시켰다. IBP의 분해(分解)는 $Cr>Cu{\geqq}Zn{\geqq}Cu$순(順)으로 억제(抑制)받았으나, Ni는 분해(分解)에 거의 영향(影響)을 주지 않았다. 그리고 butachlor의 분해(分解)는 Cr>Cu>Cd>Ni>Zn순(順)으로 억제(抑制)되었다.

• Animal cells and systems
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• 제10권4호
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• pp.211-217
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• 2006

Heavy metals are well known as important environmental pollutants and also considered as endocrine disrupters. This study was performed to evaluate the direct effects of heavy metals such as cadmium (Cd), zinc (Zn), mercury (Hg), lead (Pb), cobalt (Co), and arsenic (As) on the various steroidogenic enzymes in frog ovarian follicles. Ovarian follicles from Rana catesbeiana were isolated and cultured for 18 hours in the presence of frog pituitary homogenate (FPH, 0.05 gland/ml) or various steroid precursors with or without heavy metals (0.01-100 ${\mu}M$), and steroid levels in the follicle or culture medium were measured by radioimmunoassay (RIA). Thus, the steroidogenic enzyme activities were indirectly evaluated by measuring the converted steroid levels from the added precursor steroid. Among heavy metals, Hg, Cd and Zn significantly inhibited FPH-induced pregnenolone ($P_5$) production by the follicles ($EC_{50},\;4.0{\mu}M,\;25.6{\mu}M\;and\;5.7{\mu}M$, respectively ), and also suppressed the conversion of testosterone (T) to estradiol $17{beta}\;(E_2)\;(EC_{50},\;4.2{\mu}M,\;7.5{\mu}M\;and\;80.0{\mu}M) while Pb, Co and As are not or less effective in the inhibition. Other enzymes such as $C_{17-20}$ lyase and $17{\beta}$-hydroxysteroid dehydrogenase ($17{\beta}$-HSD) were suppressed only in the high concentration of Hg, Cd and Zn. Taken together, these data demonstrate that cytochrome P450 side chain cleavage (P450scc) and aromatase are much more sensitive to heavy metals than other steroidogenic enzymes and Hg, Cd and Zn show stronger toxicity to follicles than other heavy metals examined.

• Advances in Traditional Medicine
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• 제10권3호
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• pp.141-149
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• 2010

A concern of safety issue for traditional herbal medicine is the possibility of some herbs containing heavy metals responsible for several cases of metal poisoning. In our previous study, the physiological levels of heavy metals, such as Cd, Cu, Hg and Pb, were examined to evaluate a potential risk in patients taking herbal medicine. In this study, the levels of 12 heavy metals, including non-metallic element, Se, were analyzed in hair and compared to the results from the previous study. In the previous study, the levels of Cd, Cu, Hg and Pb in hair showed a significantly lower odds ratio than 1. In this study, however, all metals did not show any significant odds ratio higher or lower than 1 even if 5 of 12 metals showed lower odds ratio than 1. In addition, the levels of metal concentrations, especially for Cu, Fe, Pb and Zn, exceeding the WHO reference values were observed in hair. However, any evidence for metal accumulation in hair caused by taking herbal medicines for long duration was not observed in analysis of multiple regression and odds ratio from case-control study. This result would show another possibility for a role of herbs as a non-enzymatic chelator inhibiting the gastrointestinal absorption of heavy metals.

• 자원리싸이클링
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• 제22권5호
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• pp.3-12
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• 2013

수요확대가 전망되고 공급구조가 경직된 금속자원은 각국의 산업구조 및 자원확보 역량에 따라 리스크 관리가 필요하다. 이를 위해 금속자원의 위기성 평가가 다양화되고 있는데, 주로 희토류 등 희유금속이 위기물질 혹은 중요물질(Critical materials, Critical metal, Critical raw materials)로 선정되고 있다. 본 연구에서는 기술변화 및 수급불균형 등을 고려한 위기물질 선정체제 및 관리현황에 대해 살펴보고자 한다. 유럽, 미국 등은 신재생에너지 보급 확대에 따른 원재료 리스크를 평가하고 있으며, 일본은 자국 내 성장동력산업을 중심으로 핵심 원재료를 파악하고 있다. 영국은 자원채굴에 따른 환경부하를 고려하여 광종별 위기성을 평가하였다. 그리고 이러한 위기물질들의 가격시그널의 미약성, 비탄력적 공급구조, 기술변화에 민감한 수요변동성 등의 특징을 분석하였다.

• 지질공학
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• 제12권2호
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• pp.203-214
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• 2002

벤토나이트의 중금속 흡착에 대한 다양한 실험적 조건을 만족시키기 위하여 박스-벤켄(Box-Benken)의 통계적 모델을 적용하였다. 모델에 의하여 pH, 중금속의 초기농도, HCO$_3$을 변수로 하고, 각 변수에 대한 농도를 3차원으로 설정하여 벳치 실험을 실시하였다. 실험에 선택된 중금속은 Pb, Cu, Zn, Cd 4종이다. 중금속의 흡착거동에 대한 각 변수들의 영향을 표면반응 분석을 통하여 3차원으로 모델링하였다. 중금속의 흡착제거에 중금속의 초기농도와 pH가 거의 비슷한 정도로 큰 영향을 미치고 중탄산은 큰 영향을 미치지 못한다. 중금속간의 흡착경쟁은 Pb>Cu>Zn>Cd의 순서를 보인다. 아울러 pH 변화가 중금속 흡착에 미치는 영향을 실험적 및 열역학적 분석을 통하여 알아보았다. 중금속의 수산화 화합물과 탄산염 복합체의 형태로 침전이 흡착제거에 중요한 변수임이 밝혀졌다. WATEQ4F 열역학 프로그램에 의한 종분포 모델링 결과가 흡착실험결과와 다소 상이함을 보이므로 프로그램의 열역학 자료의 수정이 필요하다.

• 대한금속재료학회지
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• 제50권9호
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• pp.677-684
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• 2012

A feasible way to fabricate in-situ Al/TiC composites was investigated. An elemental mixture of $Al-TiO_2-C$ pellet was directly added into an Al melt at $800-920^{\circ}C$ to form TiC by self-combustion reaction. The addition of CuO initiates the self-combustion reaction to form TiC in $1-2{\mu}m$ at the melt temperature above $850^{\circ}C$. Besides the CuO addition, a diluent element of excess Al plays a significant role in the TiC formation by forming a precursor phase, $Al_3Ti$. Processing parameters such as CuO content, the amount of excess Al and the melt temperature, have affected the combustion reaction and formation of TiC, and their influences on the microstructures of in-situ Al/TiC composites are examined.

• Environmental Engineering Research
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• 제24권2호
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• pp.331-338
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• 2019

Particulate matter (PM) was collected using micro-orifice uniform deposit impactors from a residential (RES) site and an industrial (IND) site in Ulsan, South Korea, in September-October 2014. The PM samples were measured based on their size distributions (11 stages), ranging from $0.06{\mu}m$ to over $18.0{\mu}m$. Nine trace metals (As, Se, Cr, V, Cd, Pb, Ba, Sb, and Zn) associated with PM were analyzed. The PM samples exhibited weak bimodal distributions irrespective of sampling sites and events, and the mean concentrations of total PM (TPM) measured at the IND site ($56.7{\mu}g/m^3$) was higher than that measured at the RES site ($38.2{\mu}g/m^3$). The IND site also showed higher levels of nine trace metals, reflecting the influence of industrial activities and traffic emissions. At both sites, four trace metals (Ba, Zn, V, and Cr) contributed to over 80% of the total concentrations in TPM. The modality of individual trace metals was not strong except for Zn; however, the nine trace metals in $PM_{2.5}$ and $PM_{10}$ accounted for approximately 50% and 90% of the total concentrations in TPM, respectively. This result indicates that the size distributions of PM and trace metals are important to understand how respirable PM affects public health.