The current research plan was designed to investigate occurrence, source origin and association of heavy metals (HMs) in multi-matrix (road dust, soil and vegetation) samples along elevation gradients of Himalayan foothill, Pakistan. Therefore for this purpose, road dust (n = 28), soil (n = 42) and vegetation (n = 125) samples along different elevation gradients were collected and analyzed for HMs concentrations on flame atomic absorption spectrophotometer. Higher ∑HM concentrations were recorded in soil, dust and vegetation samples at the high elevation zones [Temperate (zone-3) and moist-temperate (zone-4)]. A clear elevation trends for cadmium (Cd), and manganese concentration in soil and Cd concentration in vegetation samples at zones were depicted but on site basis there was no clear elevation trends for the targeted metals. Stable Carbon isotopic method in soil reported that air-borne sources and geological rock outcropping are the main contributors and have shown strong positive relation with elevation, temperature, precipitation, sand, silt, and total organic carbon. Principal component analysis/multiple linear regression predicted multiple HMs pollution sources (long range atmospheric transport (LRAT), wet deposition, parent rock materials, vehicular emissions and to some extent air-borne sources) as contributor in soil, dust and vegetation samples. The geo-accumulation index (I_geo) in soil predicted that all four zones were confirmed as moderately to strongly polluted for Cd; unpolluted to moderately polluted for lead and designated as unpolluted zones for all other HMs. Further, the future in-depth studies regarding LRAT phenomenon is needed to study the fates, behaviors’ and deposition patterns of HMs in soil and vegetation.

当前的研究计划旨在调查巴基斯坦喜马拉雅山麓丘陵海拔梯度上的多基质（道路尘埃，土壤和植被）样品中重金属（HMs）的发生，来源和相关性。因此，为此目的，道路灰尘（n  = 28），土壤（n  = 42）和植被（n = 125）沿不同海拔梯度收集样品，并在火焰原子吸收分光光度计上分析HMs浓度。在高海拔地区[温带（3区）和温带（4区）]的土壤，灰尘和植被样品中记录到较高的∑HM浓度。描绘了区域中镉（Cd），土壤中的锰浓度和植被样品中Cd浓度的明显上升趋势，但根据现场情况，目标金属没有明显的上升趋势。土壤中的稳定碳同位素方法报告说，气源和地质岩层露头是主要因素，并且与海拔，温度，降水，沙，粉沙和总有机碳表现出强烈的正相关关系。主成分分析/多元线性回归预测了多种HMs污染源（远距离大气传输（LRAT），湿沉降，母岩材料，车辆排放物以及一定程度上的空气传播源）是土壤，粉尘和植被样品的来源。地理积累指数（我_地理）在土壤中预测，所有四个区被确认为中度到强烈污染镉; 未污染至中度污染的铅，并指定为所有其他HM的未污染区。此外，未来需要对LRAT现象进行深入研究，以研究土壤和植被中HM的命运，行为和沉积方式。