ions are introduced into the human body, including the consumption of food that has been contaminated with heavy metals, the ingestion of water that has been contaminated with heavy metals, skin contact, and the inhalation of air that has been contaminated with heavy metals [6; 7]. Heavy metal compounds are accountable for covalent bonds, which are known to be extremely hazardous in metalloid compounds. The propensity of heavy metals to covalently attach to organic groups is well documented, leading to the formation of lipophilic compounds or ions [8]. These metallic compounds are lipophilic, allowing them to effortlessly traverse cell membranes and gain entry into cells [9]. The interaction of these metallic compounds with cell organelles can result in toxic effects. The imperative requirement to eliminate heavy metals from polluted water and soil arises from their elevated toxicity [10].  
Several technologies have been created to decrease the existence of detrimental heavy metals in water [11]. For the treatment of heavy metals, the most common approach is physicochemical, including filtration, ion exchange, reverse osmosis, desorption, and precipitation [12]. Precipitation, in particular, is widely acknowledged for its effectiveness in eliminating As, Cu, Cr, Pb, and Cd [12]. This method operates through the alteration of wastewater pH levels. It should be noted, however, that these physicochemical techniques are often associated with high costs and the generation of secondary chemical sludge [12; 13]. In light of the limitations outlined above, it is of utmost importance to develop techniques that are both cost-effective and environmentally friendly, as these are essential to the removal of heavy metals from water and soil [14].  
As a result of their commendable cost-effectiveness and environmentally sustainable nature, an extensive range of techniques and strategies for bioremediation have been identified, including, but not limited to, biosorption, bioreduction, bioaccumulation, mycoremediation, bacterial bioremediation, and phytoremediation [10]. Specifically, bioremediation has demonstrated an economical and ecologically sound approach to extracting heavy metals from contaminated sites [15]. In addition to rice and wheat husk, activated carbon, lignite, agricultural waste, bananas and citrus peels, and green-synthesized nanoparticles have been used as active biosorbents to effectively remove and eradicate heavy metal pollution [16]. In addition, it has been established through scientific research that living microorganisms, encompassing microalgae as well as bacteria, and plants are significantly efficacious in the role of bioremediation agents [10]. This is primarily attributed to their remarkable attributes of possessing high heavy metal tolerance properties, which have been demonstrated to be key determinants of their effectiveness in this regard [17]. The surface of bacterial cells is replete with a myriad of functional groups that are intimately involved in the binding of heavy metals, which may occur either to the cell membrane or in a reduced state. This intricate interplay effectively serves to mitigate the deleterious effects of heavy metal toxicity [18; 19].  
This review is focused on heavy metal contamination in water and soil, with natural and anthropogenic sources. Moreover, this review is also focused on the heavy-metal-mediated carcinogenicity and microbial-based techniques for the removal of certain heavy metals such as As, Cr, Cd, Pb, and Cu from contaminated water and soil.