Heavy Metals

● Any metallic chemical element that has a relatively high density (> 5 g/cm 3) 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)

● Source of Heavy Metals:

Natural Sources:

» Geographical phenomena like volcanic eruptions, weathering of rocks, leaching into rivers, lakes and oceans due to action of water.

Anthropogenic Sources:

» Released into the water through anthropogenic activities such as mining, manufacturing, electroplating, electronics, discharge from auto exhaust, domestic waste, agricultural waste and fertilizer production.