• Title/Summary/Keyword: Heavy-metals

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Heavy Metal Pollution in Sub-Saharan Africa and Possible Implications in Cancer Epidemiology

  • Fasinu, Pius Sedowhe;Orisakwe, Orish Ebere
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3393-3402
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    • 2013
  • The increasing scourge of cancer epidemiology is a global concern. With WHO emphasizing that 40% of all cancer cases are preventable, exposure to known and suspected carcinogens must be discouraged. The battle with communicable diseases and other third world challenges has greatly de-emphasized anti-cancer campaigns in sub-Saharan Africa. The abundant deposit of mineral resources in sub-Saharan Africa has attracted high mining activity with its negative environmental aftermath. Poor regulatory mechanisms have led to environmental contamination by products of mining including heavy metals. In addition to poor urban planning, the springing up of settlements in industrial areas has led to generation and exposure to more hazardous wastes consequent on poor disposal systems. Studies establishing close association between exposure to heavy metals and cancer epidemiology in sub-Saharan Africa are increasing. The current review assesses the level of environmental pollution by heavy metals in sub-Saharan Africa, and brings to the fore available evidence implicating such in the increasing cancer epidemiology in the sub-continent.

국내 토양공정법과 산처리 방법의 비교: 최종 pH와 용출률의 관계

  • 이평구;최선규;오창환;이재영
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.05a
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    • pp.46-51
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    • 2000
  • Environmental quality regulations are used to establish the maximum permissible concentrations of heavy metals before a site can be deemed to be polluted or contaminated. This paper compares the results obtained by 0.IN HCl extraction and acid extraction method(HNO$_3$+HClO$_4$.HCl). The leaching efficiency of 0.1N HCl extraction is directly proportional to the final pH of leachate, due to the different solubilities of the heavy metals at different pH values, The severe differences between 0.1N HCl-extractable and total metal contents result mainly from the buffering effect of carbonates, present in sediment. samples. Application of sequential extraction experiments to some sediments collected from gully pot in Seoul illustrates a much stronger scavenging effect by Fe and Mn-hydroxides, carbonates and organic phases. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be: Mn>Zn>>Co>Cd>>Cu>Pb>Cr>Fe, in spite of large differences in heavy metal content and localization. Changes in the physicochemical environments (such as acidification) caused by a traffic accident may result in the severe environmental pollution of heavy metals of surrounding area( surface water and rivers).

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Chemical forms of Heavy Metal Elements in Mine Wastes, Stream Sediments and Surrounding Soils from the Gubong Mine, Korea (구봉광산 일대 광미, 하상퇴적물 및 주변 토양에서의 중금속 원소의 존재 형태)

  • 김종옥
    • Economic and Environmental Geology
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    • v.32 no.3
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    • pp.261-271
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    • 1999
  • Mining activity in the Gubong gold mine started in 1908 and lasted up to recent days. Heavy metals derived from the activity may be porentially toxic to human life and envirinment of this area. Because metal toxicity depends on chemical associations into five operationally defined groups: exchangeable, carbonate, reducible, oxidizable, and residual fractions, and the Most of heavy metals have significant little significance (alomost<1%). And Cu is mainly associated with the oxidizable from. Total concentration of heavy metals, pH, and mineralogy affect the chemical forms of the metals. Heavy metal concentrations. Significant amounts of metal elements (5∼65.1% in Pb, 6.2∼39.7% in Zn, 8.7∼54.7% in Cd, and 3.6∼24.7% in Cu) were present in carbonate form from mine wastes, contaminated soils and sediments. High pH value and cerussite (Pb bearing carbonate mineral) in mine wastes, contaminated soils and sediments. High pH value and cerussite (Pb beraring varbonate mineral) in mine waste support this result. Areas with high corbonate bound from would have higher potentoal conamination, however, because elements of carbonate bound forms are easily mobilized under lower pH conditions in the surface envionments due to acid to rain soil acidification.

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Distribution of heavy metals and cyanide in tailings, soils, and stream sediments around Gubong disused mine (구봉광산 주변 토양에서의 중금속과 시안의 분포)

  • 김선태;윤양희;박제안;심의섭
    • Journal of Korea Soil Environment Society
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    • v.4 no.1
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    • pp.35-47
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    • 1999
  • Mine tailings, soils. stream sediments around Gubong disused mine were analyzed in order to investigate their distribution and pollution levels of heavy metals and cyanide. The average contents of As, Cd, Cu. Hg, Pb, Zn, and CN ̄ in mine tailings were 6.93$\times$$10^{3}$, 56.9, 209, 5.03, 3.25$\times$$10^{3}$, 1.89$\times$$10^{3}$, 21mg/kg respectively. The pollution indices that calculated by the tolerance level of Kloke were 42~95 and the pH values were slightly alkaline in mine tailings. The contents of heavy metals and cyanide in field soils near the mine were higher than the paddy soils. The contents of heavy metals in the stream sediment were up to that of the tailings, so contamination from the mine tailings were serious.

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Heavy Metals in Water, Sediments and Molluscs along Coast Line Close to the Estuaries of Gum-Gang (River) and Mangyeong-Gang (만경강 및 금강 하구 지역 패류의 중금속 함량)

  • 유일수;이종섭;소진탁;김재진
    • The Korean Journal of Malacology
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    • v.7 no.1
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    • pp.87-93
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    • 1991
  • Heavy metals, Cd, Pb, Cu, Mn, Zn in water, sediments and molluscs along coast line of Hwang-hae(Yellow sea)were examined. The collection sited werer close to esturies of Kum-gang and Mankyeong-Gang, where industries have been rapidly developed along the rivers in recent in recent years. Cadmium and lead in water were 0.32ppb and 4.12 ppb respectively on Kun-san, but not on Jang hang. In general, Cd, Pb, Mn and Zn were detected in the regions of mouth paart of rivers, whereas none or far less amounts were detected from Puan, a control site: 20km apart from estury of Mangyeong Gang. Cd and Pb in sediments of Kunsan were 0.46ppm and 9.31ppm respectively and 0.36ppm and 0.41ppm in Shim-po, but far less amounts in Byeon san.Heavy metals in shellfish were: Cd 0.78ppm and Pb 0.42ppm in Kun san, 0.74ppm and 0.74ppm in Shim po, and showed higher values compare to other sites. In general, heavy metal contamination of sedimets and molluscs in each are were correlated with grade of the water pollution due to heavy metals.

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Quantitative Analysis of Heavy Metals in Packaging Papers

  • Jo, Byoung-Muk;Jeong, Myung-Joon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.5
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    • pp.45-51
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    • 2007
  • This study was carried out to investigate various heavy metal contents in packaging papers by pre-treatments for ICP-ES (Inductively Coupled Plasma Emission Spectrometry) analysis. Pre-treatment methods of heavy metals in this study include extraction, migration and decomposition methods (dry ashing, $HNO_3-HClO_4-HF,\;HNO_3,\;and\;H_2SO_4-HNO_3$). Test results were compared with conventional extraction (water) and migration (3% acetic acid) methods. The five representative heavy metals (Cd, As, Pb, Cr and Hg) were analyzed. For Cd, Hg, and As, the results were below detection limit of the instrumental technique. It was considered that the migration test was a better method compared to extraction test, but all the decomposition methods showed much higher detection values than the extraction or migration test. In case of recycled corrugated containers, 3% acetic acid solution extracted about 25% of chromium and 30% of lead compared to the content by decomposition methods. Among all decomposition methods, the nitric acid - perchloric acid - hydrofluoric acid treatment brought a slightly higher detection value than others, but there was no significant difference among them except sulfuric acid - nitric acid method.

Characteristics of Heavy Metal Emissions from Stationary Sources (고정오염원에서의 중금속 배출특성 연구)

  • Park, Jung-Min;Lee, Sang-Bo;Cha, Jun-Seok;Kwon, Oh-Sang;Lee, Sang-Hak
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.5
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    • pp.574-583
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    • 2008
  • The results of HAPs emission data using TRI (Toxic Release Inventory), SODAM (Source Data Management system) were investigated and the emissions of 7 heavy metals from their sources and emission processes were also analyzed. Questionnaire for source data analysis as well as the stack sampling were carried out for 17 factories among 6 selected industrial types. The annual amount of emissions was estimated based on the measured concentration and flow rates. All sources were operated with high efficiency control devices and the concentration levels of all heavy metals were shown to be below 0.1 to of regulation standard. The highest emission source of heavy metals was steel manufacturing industry with the annual emission of 342.9 kg/yr and followed by hazardous waste incinerator, paint manufacturing, nonferrous metal manufacturing, rolling & press goods manufacturing and storage battery manufacturing. In the case of Hg, the emissions were quite significant from electric acros of steel manufacturing industry, although the concentration level was below the emission standard, showing the necessity of specific care for its management.

Natural and Anthropogenic Heavy Metal Deposition to the Snow in King George Island, Antarctic Peninsula

  • Hong, Sung-Min;Lluberas, Albert;Lee, Gang-Woong;Park, Jun-Kun
    • Ocean and Polar Research
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    • v.24 no.3
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    • pp.279-287
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    • 2002
  • Successive 24 snow samples, collected from a 1.2m snow pit at a site on the summit of Main Dome in King George Island, Antarctic Peninsula, were measured for heavy metals such as Pb, Cd, Cu, and Zn and other chemical species. The mean concentrations of heavy metals are 3.48pg/g for Pb, 0.10pg/g for Cd, 16.6 pg/g for Cu and 15.8 pg/g for Zn, respectively. Pb and Cd concentrations observed in our samples are very comparable to those reported for recent snow at other Antarctic sites, while Zn and Cu levels are much higher than those at other sites. The annual fallout fluxes of all heavy metals approximately calculated are, however, much greater in King George Island than at other sites. With respect to the estimates of natural contributions, sea salt spray is found to be a major contributor to Cd and Zn inputs to the snow and minor to Cu inputs. On the other hand, the anthropogenic input can account for a large part of Pb concentrations. A tentative estimate represents that local emissions could be responsible for more than half of the excess Pb flux to the snow in King George Island.

A Study on the Fixation of Heavy Metals with Stabilized Soils in the Landfill Liner (폐기물매립지 차수재로서 고화토의 중금속 고정능력 평가에 관한 연구)

  • 노희정;이재영
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.145-149
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    • 2000
  • We performed the geotechnical experiments of the hydraulic conductivity and compressive strength test with the stabilized soil in the laboratory, proved that it is useful to use the stabilized soil as an alternative for natural clay soil. Also, for mixing adding materials in the stabilized soil, it was determined that 1) the optimal mixing ratio of cement : bentonite : stabilizing agent was 90:60:1 of mass ratio(kg) for 1㎥ with soil, 2) it was also possible to use low quality bentonite(B\circled2) classified by swelling grade because of little difference from results of the hydraulic conductivity and compressive strength test with high quality bentonite(B\circled1). According to the results of the fixation ability of heavy metals(Pb$^{2+}$, Cu$^{2+}$, Cd$^{2+}$, Zn$^{2+}$) with soil and additives, authors can conclude that the higher pH condition had the more removal efficiency of heavy metals. B\circled1 and cement had especially high removal efficiency of heavy metals in a whole pH because of high alkalinity.alinity.

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Mineralogical Characteristics and Removal of Heavy Metals from Gum-poong Mine Tailings (금풍광산(鑛山) 광물(鑛物)찌꺼기의 광물(鑛物)학적 특성(特性) 및 중금속(重金屬) 제거(除去))

  • Cha, Jongmun;Park, Jayhyun;Kang, Heon Chan
    • Resources Recycling
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    • v.21 no.6
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    • pp.51-57
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    • 2012
  • The objective of this study was to research the mineralogical characteristics and removal of heavy metals of tailings from Gum-poong mine. From the result of mineralogical analysis, there are several sulphide minerals such as chalcocite, aresenopyrite, pyrite, sphalerite and galena. Cd and Zn have a good positive correlation from the statistical relation between Cd and other heavy metals(Cu, Pb, Zn). Residual heavy metals(As, Cd, Cu, Pb, Zn) from the Gum-poong tailings were removed under the warning criteria from the result of froth flotation with K.A.X.(Potassium Amyl Xanthate) and Aerofloat 211.