*Heavy Metal's Environmental Impact DOI: http://dx.doi.org/10.5772/intechopen.103907*

Heavy metal ions are extremely harmful to both plants and animals in the soil environment, as they are absorbed by plants and eventually reach animals and people [15]. A set of metals and metalloids having an atomic density larger than 4000 kg/ m3 is referred to as "heavy metal" (four times the density of water). Heavy metals are present in rocks, soil, plants, and animals and occur naturally in the environment. Metals can be found in a variety of forms, including dissolved ions in water or vapor, as well as minerals in rocks, sand, and soil. These materials can also form bonds with organic and inorganic molecules, as well as cling to airborne particles. Metals are released into the air and water by both natural and manmade mechanisms [16]. The vast range of issues surrounding the presence of HMs in the food chain and their effects on human health necessitates more research in this area as part of a holistic approach to the environment in which humans live. The anthropogenic pollution of heavy metals in ancient mining regions refers to areas where the concentration of one or more heavy metals exceeds normal values in most soils, as well as some agricultural products used as plant food, such as vegetables and fruit, and even animal products (meat, eggs, and milk) [17]. It's also crucial to identify the various sources of heavy metals in the environment and establish their total concentration. Element speciation, profile distribution, and spatial distribution are common methods for distinguishing between anthropogenic and geogenic sources of potentially toxic elements, but they are insufficiently reliable to distinguish between sources of element concentration on their own and should be combined with additional information such as parent rock composition or known anthropogenic sources [18]. Heavy metals have been found to disrupt cellular organelles and components in biological systems, including the cell membrane, mitochondria, lysosomes, endoplasmic reticulum, nuclei, and several enzymes involved in metabolism, detoxification, and damage repair [19]. Nanoscale

#### **Figure 1.**

*Sources, migration and toxicity of heavy metals [23].*

zero-valent iron is a promising alternative for heavy metal cleanup, with high efficiency and low economic costs [20]. It has a bigger specific surface area, reduction reactivity, and high surface energy. Such dangerous forms of heavy metals may survive in our environment for longer periods, and once they come into touch with the land, water, and soil, they may pose harm to living things [21].

Currently, the study region is endowed with significant mineral resources that span the whole state. Illegal mining of these minerals has resulted in the occurrence of HMs in soil and water supplies. Land application of fertilizers, animal manures, sewage sludge, pesticides, mining tailings, mechanic wastes, and disposal of heavy metal wastes are further sources of HMs [22]. Heavy metals are thought to arise from two basic sources: natural inputs (such as parent material weathering) and human inputs (such as metalliferous industries and mining, automobile emissions, agricultural practices, and so on) [23]. As a result, identifying metal sources is critical before implementing various pollution cleanup measures. The majority of current research is done on mid-to large-scale (for example, mining areas, industrial areas, large cities, etc.) as shown in **Figure 1** [23].
