HEAVY METAL TOXICITY AND THEIR HARMFUL EFFECTS ON LIVING ORGANISMS – A REVIEW

Abstract

The contamination chain of heavy metals almost always follows cyclic order in the environment as industry, atmosphere, soil, water, foods and human. As it is clear that chronic exposure to heavy metals and metalloids at low levels cause the adverse effects. Heavy metals have been proved to be toxic to human and environmental health. Heavy metal toxicity is regarded as major threat and there is several health risks associated with it. Sometimes they may act as pseudo elements of the body but event at certain times they may interfere with metabolic processes. Few metals, like aluminum, can be removed by elimination activities, while some of the metals get accumulated in the body and food chain, exhibiting a chronic nature. Different public health procedures have been taken to control, prevent and treat metal toxicity which occurs at various levels, such as occupational exposure and environmental factors. Metal toxicity depends on the dose absorbed, route of exposure and duration of the exposure, which can lead to different disorders and results in excessive damage due to oxidative stress induced by free radical formation. This review provides insight into the sources of heavy metals and their harmful effects on environment and living organisms.

Key words: heavy metals, metal toxicity, oxidative stress, free radicals