**2. Heavy metal contamination**

Natural contamination of these heavy metals is a significant environmental issue due to its negative impacts all over the world. Because of rapidly increasing horticultural and metal enterprises, improper rubbish removal, manures, and pesticides, organic wastes that are being disposed of in water bodies, land soil, and the environment. A few metals have an effect on natural capacities and development, while others collect in at least one organ, creating a variety of real illnesses such as cancer. Each metal's toxicological and pharmacokinetics cycles in humans are depicted. In general, environmental auditing can tell us the effects of heavy metal bioaccumulation in the human body with context to biochemical and physiological changes, as well as the severe illnesses occurring from their exposure.

Climate is an environmental factor in which people, plants, beings, minute living beings. It comprises land, the atmosphere and the hydrosphere component. Earth is a framework that is characterized by the four pillars, the living organisms (biosphere), the atmosphere (air), the lithosphere (land) and water (hydrosphere) which are all employed in a combination. Natural toxins, just like contaminations, are synthetic substances that are available at more elevated levels than in any segment of the climate [8–10]. During the most recent years, the process of industrialization has developed at a rapid phase. This manner has expanded the interest for abuse of the Earth's regular assets which is a growing concern ecological contamination [11]. A few *Heavy Metal Contamination of Food Crops: Transportation via Food Chain, Human… DOI: http://dx.doi.org/10.5772/intechopen.101938*

poisons, such as inorganic particles, natural toxins, organometallic substances, vaporous poisons, radioactive substances and nano-based materials, have actually poisoned the climate [12, 13].

Heavy metals have existed on earth since the existence of earth. Because of an amazing increment in the usage of substantial metals which brought about a fast-approaching flood of metallic substances in both the earthbound climate and the oceanic climate [12]. The Heavy metal contamination has occurred due to anthropogenic activities, primarily due to metal mining, purification, foundries, and other metal-based ventures, as well as metal draining from various sources such as landfills, squander dumps, discharge, animals and chicken fertilizer, overflows, cars, and roadworks [7]. The usage of Heavy Metals (Heavy metals) in the industries like agriculture, pesticides, insect poisons, manures etc., has been an optional wellspring of heavy metal contamination. Eruptions from volcanoes, consumption of metals, from the environment are all examples of natural events that might increase heavy metal contamination. This contamination can travel from soil and water causing soil breakdown, and land degradation, which are all examples of natural factors that might increase heavy metal contamination [14].
