**2. Accumlation of heavy metals in vegetables**

Mechanical, biochemical, and biological processes, as well as doings of human, could releases heavy metal into the environment and may cause heavy metal contaminants to accumulate inside living creatures in the food chain [9, 10]. HMs diffuse into the soil, air, as well as water bodies, wherever they could be had or eaten by crops/ plants, bio-accumulating into upper consumers, and then biomagnified [11–13]. HMs cannot be easily removed from the top of the food chain once they have entered it, and they are thus cycled throughout the entire food web. Numerous hyperaccumulated plants provide nourishment for both humans as well as animals. As a result, the rotation from soil to humans thru plants and back into the soil following the expiry of upper consumers provides a pathway for HMs to persist in the environment for extended time periods, causing a variety of negative impacts. Ingestion vegetables containing HMs may provide potentially harmful health risks to lifeforms [14, 15] (**Figure 1**).

Heavy metals come in the food chain from a variety of sources. Cd, for example, took up from the soil by the roots and transferred to the body of plant. In the instance of Pb, the heavy metal is absorbing by plants through air pollution, whereas As and Hg can be received from dirt water. Some heavy metals having a capacity to accumulate in the tissues (liver, feathers, muscles, kidney, and other organs) of upper customers during the transit from one segment of the food chain to the next. Metal are liberated into the soil, water, and air from their parental material. These HMs are found in soil in decipherable, non-soluble, and moderately soluble forms, with the soluble forms being most harmful since they are quickly captivated by plants through roots before spreading all over the whole plant organs. Metal toxicity is caused through the disruption of cellular metabolic processes [16–19]. Hazardous metals are changed to persistent oxidation states in the acid standard and combine with particular proteins and enzymes when they reach the stomach from contaminated foods. The stabilised

*Heavy Metal Contamination in Vegetables and Their Toxic Effects on Human Health DOI: http://dx.doi.org/10.5772/intechopen.102651*

**Figure 1.** *Vegetables get contaminated through various ways.*

metal compounds interact with cysteine's sulphydryl groups (-SH) as well as methionine's sulphur atoms (-SCH3), causing protein molecules to breakdown [18, 20].
