UPSC Express

About Heavy-Metals contamination

• Heavy metals are metallic elements with an atomic number greater than 20.
• They are trace elements having a density at least five times that of water.
• Some of these elements are necessary for growth, development and functioning of living organisms
• These include Copper, zinc, chromium, iron etc.
• Those which are unnecessary include cadmium, lead, mercury.
• However, beyond a certain limit all of them are toxic for plants, animals and humans.
• These elements penetrate the body by inhalation, ingestion and skin absorption.
• If heavy metals accumulate in body tissues faster than the body’s detoxification a gradual build-up of these toxins occurs.
• Vegetables provide the trace elements and heavy metals.
• Minor or trace elements are essential for good health if they come from an organic or plant source.
• In contrast, if they come from an inorganic or metallic source, they become toxic.
• Vegetables and fruits accumulate higher amounts of heavy metals because they absorb these metals in their leaves.

Effects of heavy metals in food

• cardiovascular, kidney, nervous, bone diseases,
• decreasing immunological defences,
• intrauterine growth retardation,
• impaired psychosocial faculties,
• disabilities associated with malnutrition
• upper gastrointestinal cancer

Effects of heavy metals in air

• Manganese, lead and nickel are neurotoxins that damage the brain.
• Children are particularly vulnerable to the effects of lead.
• Exposures to even low levels of lead early in life have been linked to effects on IQ, learning, memory and behavior.
• Toxic metals are responsible for rising cases of brain strokes among youngsters in the city.