Progressive industrialization and utilization of metals in industries have resulted as rise in heavy metal distribution throughout the environment. Industrial wastes, such as liquid and gaseous discharges and discard the dumps, are an essential component of heavy metal contaminating the environment, contaminating water bodies and the ecosystem as a whole. As people are exposed to these toxicants, they accumulate in their bodies. The concentration of metal (dose) and time of exposure, the individual’s gender as well, age, and current health state about an individual are only a few of the variables that affect how harmful heavy metals are. Due to their acute toxicity, contaminants such as heavy metals, including nickel, cadmium, arsenic, and mercury. Chromium, lead, along with so on are particularly concerning for public health. Even at low doses, these metals are strong enough to cause an array of organ failures. Studies show an analogy between heavy metals and malignant tumours. High levels of metal exposure have been linked to possible health risks in a number of ways. Even though and these substances don’t have any kind ecological function, it’s harmful consequences never the less exist and are detrimental to the health of humans in one way or another. They may occasionally function as a pseudonymous component of the body or even hinder metabolism of body. The amount that was obtained, the exposure direction, and the length of becoming exposed—acute or chronic all affect the toxicity of metals. Due to oxidative stress brought on by the formation of harmful free radicals, this can cause several disorders in addition to causing irreparable harm. To manage, prevent, and treat the toxicity of heavy metals resulting across a variety within sources, including exposure at work, accidents, along with environmental causes, a number of public health initiatives have been implemented. This chapter gives a complete overview of the harmful effects of heavy metals including bismuth, cadmium, cobalt, iron, lead, mercury, tin, thallium, aluminium, antimony, arsenic, and bismuth, as well as their toxicity mechanisms and health impacts. The effects that some dangerous metals have on proteins and enzymes, both physiologically and biochemically have been addressed as well.