Toxicological Scenario of Heavy Metals on Human Health: Current Status

Abstract

Heavy metals are persistent environmental contaminants and naturally occurring elements of the Earth's crust. There are several ways that humans might be exposed to heavy metals, such as through the food chain, consuming contaminated water or soil, or breathing in air or dust particles. Their bioaccumulation may have a variety of harmful impacts on various organ systems and bodily tissues. The characteristics of the particular metal, dose, route, length of exposure (acute or chronic). The ability of heavy metals to disrupt antioxidant defense mechanisms, mainly through their interaction with intracellular glutathione (GSH) or sulfhydryl groups (R-SH) of antioxidant enzymes like superoxide dismutase (SOD), catalase, and other enzyme systems. Although arsenic (As) is believed to bind directly to critical thiols, alternative hydrogen peroxide production processes have also been postulated. Numerous biological processes, such as cell development, proliferation, survival, metabolism, and apoptosis, are known to be impacted by heavy metals, which also disrupt signaling pathways. It has been demonstrated that nuclear factor erythroid 2-related factor 2 (Nrf2) functions as a double-edged sword in response to arsenic-induced oxidative stress. Nrf2 is an essential regulator of antioxidant enzymes, the degree of oxidative stress, and cellular tolerance to oxidants.