The present study aims to investigate the distribution of selected potentially toxic elements (PTEs) in Kazakhstan's topsoils. Soil samples collected across a north-south gradient (n = 40) near main highways connecting major residential/industrial areas were characterized for their As, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn content as well as for soil physio-chemical properties. The majority of the soils had neutral pH (no significant relationship between pH and PTE concentrations). The soil organic carbon was higher at the northern and farther southern parts of the transect (along with higher concentrations of PTEs in soils). As, Mn, and Ni concentrations in soils were elevated in comparison to relevant background concentrations. Critical concentrations of As, Cd, Co, Mn, and Ni (with respect to regulatory limits) were found at multiple locations, with As being particularly of potential concern (range: 8.7–42 mg × kg⁻¹). The distance from the nearest settlement seems to influence the soil PTE concentrations, however the relationship is not statistically significant. In total, eight locations had statistically outlier PTE concentrations for Cd, Mn, Ni, and Zn. The overall results were comparable to similar studies across the world except that the Pb content of the study soils was less elevated. Studies on site characterization and human health risk assessment covering identified hotspots and PTEs are recommended.

本研究旨在调查哈萨克斯坦表层土壤中选定的潜在有毒元素（PTE）的分布。沿南北坡度收集的土壤样品（n = 40）在连接主要住宅区/工业区的主要高速公路附近对其As，Cd，Co，Cr，Cu，Mn，Ni，Pb和Zn含量以及土壤理化特性进行了表征。大多数土壤具有中性pH（pH和PTE浓度之间无显着关系）。在样带的北部和南部，土壤有机碳含量较高（以及土壤中PTE的浓度较高）。与相关背景浓度相比，土壤中的As，Mn和Ni浓度升高。在多个位置发现了As，Cd，Co，Mn和Ni的临界浓度（相对于法规极限），As尤其令人关注（范围：8.7–42 mg×kg ^-1）。离最近定居点的距离似乎会影响土壤PTE浓度，但是这种关系在统计上并不显着。总计，八个位置的Cd，Mn，Ni和Zn的PTE浓度在统计上都离群。总体结果与世界各地的类似研究相当，不同之处在于研究土壤中的铅含量较低。建议研究涵盖已确定的热点和PTE的场所特征和人类健康风险评估。