尼日利亚伊巴丹电子垃圾回收作业附近有毒金属造成的土壤污染。
Soil Pollution by Toxic Metals near E-waste Recycling Operations in Ibadan, Nigeria.
作者信息
Adesokan Michael D, Adie Gilbert U, Osibanjo Oladele
机构信息
Department of Chemistry, Faculty of Science, University of Ibadan, Ibadan, Nigeria.
出版信息
J Health Pollut. 2016 Sep 13;6(11):26-33. doi: 10.5696/2156-9614-6-11.26. eCollection 2016 Sep.
BACKGROUND
Unsound recycling of e-waste releases toxic metals into environmental media and has deleterious health consequences to humans as the metals transfer to humans through the food chain, direct contact and inhalation.
OBJECTIVES
This study assessed soil contamination with lead (Pb), copper (Cu), chromium (Cr), nickel (Ni) and cadmium (Cd) arising from crude e-waste recycling.
METHODS
Forty-eight soil samples were collected from the vicinity of high-, medium- and low-activity recycling operations in Ogunpa in Ibadan, Nigeria as well as from the botanical garden of the University of Ibadan for background samples. Total extractable metals were leached with aqua regia and the leachates were analyzed using flame atomic absorption spectrometry. Speciation analysis was also conducted on soil samples that showed high concentrations of metals to determine the distributions in various phases.
RESULTS
All soil samples were determined to be sandy loam in composition with pH and organic matter ranging from 7.1-7.9 and 1.56-1.81%, respectively. Metal concentrations (mg/kg) for soils from the study area ranged as follows: Pb, 269 - 5650; Cu, 203 - 3483; Cr, 3.30 - 42.4; Ni, 0.14 - 24.0; and Cd, below detection limit - 2.50. The results indicated enrichment in soil by all metals, especially Pb and Cu, which were many times higher compared with background concentrations. Additionally, average Pb and Cu concentrations were higher than regulatory limits for soil set by selected countries across the globe. Speciation studies indicated that about 65% and 88% of Pb and Cu, respectively, were liable to potential mobility with slight changes in natural conditions. Other metal concentrations, although with higher concentrations compared with background levels, were within the permissible limits in soils accepted by many countries across the globe. There were significant correlations between all metals, suggesting that they may have been released from a common source.
CONCLUSIONS
Soils from the study area require urgent clean-up, especially for Pb and Cu, to safeguard human health and the environment.
背景
电子垃圾回收不当会将有毒金属释放到环境介质中，由于这些金属通过食物链、直接接触和吸入进入人体，会对人类健康产生有害影响。
目的
本研究评估了原始电子垃圾回收造成的土壤中铅（Pb）、铜（Cu）、铬（Cr）、镍（Ni）和镉（Cd）的污染情况。
方法
从尼日利亚伊巴丹奥贡帕高、中、低活动量回收作业附近采集了48个土壤样本，并从伊巴丹大学植物园采集了背景样本。用王水浸出总可提取金属，并用火焰原子吸收光谱法分析浸出液。还对金属浓度高的土壤样本进行了形态分析，以确定各相中金属的分布。
结果
所有土壤样本经测定均为砂壤土，pH值为7.1 - 7.9，有机质含量为1.56 - 1.81%。研究区域土壤中的金属浓度（mg/kg）范围如下：铅，269 - 5650；铜，203 - 3483；铬，3.30 - 42.4；镍，0.14 - 24.0；镉，低于检测限 - 2.50。结果表明所有金属在土壤中均有富集，尤其是铅和铜，其含量比背景浓度高出许多倍。此外，铅和铜的平均浓度高于全球选定国家设定的土壤监管限值。形态研究表明，分别约65%的铅和88%的铜在自然条件稍有变化时就易于发生潜在迁移。其他金属浓度虽然高于背景水平，但在全球许多国家认可的土壤允许限值范围内。所有金属之间均存在显著相关性，表明它们可能来自同一来源。
结论
研究区域的土壤需要紧急清理，尤其是铅和铜污染土壤，以保障人类健康和环境安全。
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