Heavy Metals

Heavy Metals Latest News

Heavy metals are polluting the Cauvery River and its fish, researchers from Tamil Nadu have reported.

About Heavy Metals

• The term ‘heavy metal’ refers to any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations. 
• Examples of heavy metals include mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (Tl), and lead (Pb). 
• Heavy metals are natural components of the Earth’s crust. They cannot be degraded or destroyed. 
• To a small extent they enter our bodies via food, drinking water, and air. 
• As trace elements, some heavy metals (e.g. copper, selenium, and zinc) are essential to maintain the metabolism of the human body. 
• However, at higher concentrations they can lead to poisoning.
• Heavy metal poisoning could result, for instance, from drinking-water contamination (e.g. lead pipes), high ambient air concentrations near emission sources, or intake via the food chain. 
• Heavy metals are dangerous because they tend to bioaccumulate. 
  • Bioaccumulation means an increase in the concentration of a chemical in a biological organism over time, compared to the chemical’s concentration in the environment. 
  • Compounds accumulate in living things any time they are taken up and stored faster than they are broken down (metabolized) or excreted. 
• Heavy metals can enter a water supply by industrial and consumer waste, or even from acidic rain breaking down soils and releasing heavy metals into streams, lakes, rivers, and groundwater.
• Mercury, lead, and cadmium are of greatest concern because of their ability to travel long distances in the atmosphere.

Source: TH

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