## 1 Introduction  
The balance in the ecosystem is significantly disrupted by the infiltration of invasive alien plant species (IAPS), negatively affecting valuable native plant species, resulting in biodiversity loss [1]. The favorite hotspot for IAPS is polluted soils due to lack of competitors and also because IAPS have the potential to withstand harsh conditions, whereas native plants fail to tolerate and propagate [2]. These plants develop specific physiological and biochemical mechanisms to function normally on lands polluted with heavy metals, forming heavy metal-resistant populations [3]. Heavy metals are non-degradable pollutants, and their hyperaccumulation is a matter of great concern because of their contamination and toxicity in the natural environment [4]. Soil and air contaminated with heavy metals affect the quality of the environment and pose threats to living organisms and human beings. In soil, heavy metal pollutants leach to plant roots through absorption, thereby entering the living system, subsequently bioaccumulating and magnifying in the upper trophic levels. Its effect is more pronounced and explicitly lethal for living biota [5]. Heavy metals such as cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), etc. are added to soil and air through different sources and are considered a problem of great concern [6]. Likewise, increasing urbanization and industrialization throughout the globe make this an urgent issue [7] due to severe threats to the environment by discharging different pollutants in effluents [8]. Vehicular emissions are considered the main source contaminating areas near to roads and many other accessible urban and rural areas [8]. The most common metals released by vehicles via different processes include Cd, Pb, zinc (Zn), nickel (Ni), Cu, and iron (Fe) [9; 10; 11]. Pb and Cd are nonessential heavy metals, as they are naturally not found within organisms, and have no metabolic function in biological systems. Zn and Cu are essential heavy metals that are required in small quantities for normal plant growth. However, excess quantities can be lethal, causing different abnormalities [12]. Physiological functions such as nutrient absorption, photosynthesis, and gaseous exchange in plants are reduced/ceased by metal toxicity. It can also reduce growth, yield, and dry matter accumulation [13]. These metals cause cancer, cardiovascular and neurological disorders, diabetes, and atherosclerosis [14]. Possible sources of these metals are fossil fuel combustion; wear and tear of automobile tires; metals in catalysts; degradation of various vehicle parts, especially pains; and many other industrial operations [15]. In phytoremediation, plants extract soil pollutants and accumulate them in various functional parts [16]. The roads and industrial zone soils are multi-element contaminated soils, and cleaning of such soils can be negatively influenced if the hyper-accumulator cannot adapt to soils with high concentrations of several toxic elements [10]. Bioaccumulation (BAF) and translocation factor (TF) have been applied for evaluating the plant's ability to absorb heavy metals from the soil and translocate to different plant parts. BAF is a ratio of heavy metal concentration in biota to that in soil. It is an appropriate measure of the capability of native plants for heavy metals uptake, e.g., [17; 18; 19; 20]. Nevertheless, very few studies have explored the effects of invasive plant on heavy metals contamination in the soil resulting from traffic emissions in roadside and industrial farmlands, e.g., [21; 22; 23; 24; 25]. _Xanthium strumarium_ L., belonging to the family Asteraceae, is one of the emerging invasive plant species currently invading croplands and non-cropped areas in Khyber Pakhtunkhwa, Pakistan [26]. This plant species originated in South or Central America, and spread gradually towards North America, where it grows near rivers and shores, dispersing through water and animals [27].