The concentrations of zinc, copper, lead and cadmium owing to vehicles were analyzed in roadside soils during all the four seasons from Faisalabad-Gojra road (M-4) and Gojra-Jhang road (GJR) in the Punjab, Pakistan. Results indicated that all the polluted sites along the roadside had comparatively higher metal concentrations as compared to control, nevertheless, spatio-temporal variations in metal concentrations were apparent in different soil samples. The spatial differences in metal concentrations were strongly associated with vehicle density at the Gojra Interchange site and Forest Park site along M-4 and GJR roads, respectively. Among seasons, metal ions exhibited the following order: summer > autumn > spring > winter, indicating that high temperature might have released more metal ions. The metals were recorded in contaminated soil in the order of Zn > Cu > Pb > Cd along both roads. This investigation emphasizes the need for proper environmental management particularly the improvement of roads and proper checking of vehicles running on these regards.

中文翻译：

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两条主要道路上土壤中金属污染物的时空异质性。

在巴基斯坦旁遮普邦的Faisalabad-Gojra公路（M-4）和Gojra-Jhang公路（GJR）的四个季节中，对路边土壤在整个四个季节中由于车辆造成的锌，铜，铅和镉的浓度进行了分析。结果表明，与对照相比，路边的所有污染场所的金属浓度都相对较高，但是，在不同的土壤样品中，金属浓度的时空变化是明显的。金属浓度的空间差异分别与沿着M-4和GJR公路的Gojra交汇处和Forest Park处的车辆密度密切相关。在各个季节中，金属离子表现出以下顺序：夏季>秋季>春季>冬季，这表明高温可能释放出更多的金属离子。在两条道路上，金属均以Zn> Cu> Pb> Cd的顺序记录在受污染的土壤中。这项调查强调必须进行适当的环境管理，尤其是改善道路和对这些方面行驶的车辆进行适当的检查。