Abstract：
The present study focused on to determine the concentration and health risk of heavy metals (Cu, Pb, Zn, Cd, Hg, Cr) in e-waste contaminated soils collected from different provinces of Pakistan. Further, the impact of heavy metals on soil enzyme activities and microbial community was also investigated. The concentration (mg/kg) of Hg, Zn, Fe, Cu, Pb, Cd, and Cr ranged between 0-0.258, 2.284-6.587, 3.005-40.72, 8.67-36.88, 12.05-35.03, 1.03-2.43, and 33.13-60.05, respectively. The results revealed that Lahore site of Punjab province indicated more concentration of heavy metals as compared to other sites. The level of Cr at all sites whereas Hg at only two sites exceeds the World Health Organization standards (WHO) for soil. Soil enzyme activity exhibited dynamic trend among the sites. Maximum enzyme activity was observed for urease followed by phosphatase and catalase. Contamination factor (Cf), Pollution load index (PLI), and geo-accumulation index (Igeo) results showed that all the sites are highly contaminated with Cu, Cd, and Pb. Hazard index (HI) was less than 1 for children and adults suggesting non-carcinogenic health risk. Principle component analysis results depicted relation among Cr, Fr, catalase, and actinomycetes; Cd, OM, urease, and bacteria, and Pb, Cu, Zn, Hg, and phosphatase, suggesting soil enzymes and microbial community profiles were influenced by e-waste pollution. Therefore, there is a dire need to introduce sustainable e-waste recycling techniques as well as to make stringent e-waste management policies to reduce further environmental contamination.
摘要：
本研究的重点是确定重金属(Cu，Pb,Zn,Cd,Hg,从巴基斯坦不同省份收集的电子垃圾污染土壤中的Cr）。Further,还研究了重金属对土壤酶活性和微生物群落的影响。Hg的浓度（mg/kg），Zn,Fe,Cu,Pb,Cd,Cr的范围分别为0-0.258、2.284-6.587、3.005-40.72、8.67-36.88、12.05-35.03、1.03-2.43和33.13-60.05。结果表明，与其他地点相比，旁遮普省拉合尔地点的重金属浓度更高。所有地点的Cr水平，而只有两个地点的Hg水平超过了世界卫生组织（WHO）的土壤标准。土壤酶活性呈动态变化趋势。观察到脲酶的最大酶活性，其次是磷酸酶和过氧化氢酶。污染因子（Cf），污染负荷指数（PLI），和地质累积指数（Igeo）结果表明，所有站点都受到Cu的高度污染，Cd,和Pb。儿童和成人的危险指数（HI）小于1，表明非致癌健康风险。主成分分析结果描述了Cr，Fr,过氧化氢酶,和放线菌；Cd，OM,脲酶,和细菌，还有Pb,Cu,Zn,Hg,和磷酸酶，表明土壤酶和微生物群落分布受电子垃圾污染的影响。因此,迫切需要引入可持续的电子废物回收技术，并制定严格的电子废物管理政策，以减少进一步的环境污染。
