Global Center for Environmental Remediation, The University of Newcastle, Callaghan, 2308, Australia.
Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad, 38040, Pakistan.
Environ Monit Assess. 2019 Jan 12;191(2):65. doi: 10.1007/s10661-019-7212-y.
Assessment of trace elements is inevitable to reduce stress on environment due to urbanization and industrialization. Rawalpindi, the fourth largest city of Pakistan, rapidly moving towards industrialization and has a large number of automobiles. In the present study, the urban area of Rawalpindi was divided into five parts: Gawal Mandi, Pir Wadhai, Soan Adda, Chah Sultan, and Central Ordinance Depot (COD), to determine distribution of trace elements. Soil samples were collected from 5 to 20 cm depth. After drying and sieving, samples were digested using di-acid (HNO and HClO at 2:1). Concentrations of heavy metals were determined using atomic absorption spectrophotometer (AAS). Principal component analysis (PCA) was performed to reduce multidimensional space of variables and samples. Observed mean concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn were 164, 33.4, 295, 336, 634, 236, 1572, and 546 mg kg, respectively. Mean concentrations of all the heavy metals in urban area soil were higher than the WHO permissible limits. Correlation coefficient analysis showed positive correlation among Cd, Co, Cu, Ni, and Pb, whereas no obvious correlation for Cr and Mn was found with any other heavy metal. Zn was positively correlated with Co, Ni, and Mn, whereas negative correlation was found with Cr. Results showed that Pir Wadhai and COD were the most and least contaminated parts of the city, respectively, and this is attributed to the presence and absence of heavy traffic loads and industrial effluents. Graphical abstract ᅟ.
由于城市化和工业化的发展，评估微量元素是减少环境压力的必然要求。巴基斯坦的第四大城市拉瓦尔品第正在迅速向工业化迈进，拥有大量的汽车。在本研究中，将拉瓦尔品第市区分为五个部分：Gawal Mandi、Pir Wadhai、Soan Adda、Chah Sultan 和 Central Ordinance Depot（COD），以确定微量元素的分布情况。从 5 到 20 厘米的深度采集土壤样本。干燥和过筛后，使用二酸（HNO 和 HClO 比例为 2:1）对样品进行消解。使用原子吸收分光光度计（AAS）测定重金属浓度。进行主成分分析（PCA）以降低变量和样本的多维空间。观察到 Cd、Co、Cr、Cu、Mn、Ni、Pb 和 Zn 的平均浓度分别为 164、33.4、295、336、634、236、1572 和 546mg/kg。市区土壤中所有重金属的平均浓度均高于世界卫生组织的允许限值。相关系数分析表明，Cd、Co、Cu、Ni 和 Pb 之间呈正相关，而 Cr 和 Mn 与其他重金属之间没有明显的相关性。Zn 与 Co、Ni 和 Mn 呈正相关，而与 Cr 呈负相关。结果表明，Pir Wadhai 和 COD 是城市污染最严重和污染最轻的区域，这归因于是否存在大量交通负荷和工业废水。
