PMF IAS Test Series for UPSC Prelims Banner Ad
PMF IAS Test Series for UPSC Prelims Banner Ad

Persistent Organic Pollutants (POPs), Chlorinated Hydrocarbons (Organochlorides)

Persistent Organic Pollutants (POPs)

  • POPs are defined as “chemical substances that persist in the environment, bioaccumulate through the food web, & pose a risk of causing adverse effects to human health & the environment”.
  • Persistent organic pollutants (POPs) are chemicals of global concern due to their potential for:
    • long-range transport,
    • persistence in the environment,
    • ability to bio-magnify & bio-accumulate in ecosystems,
    • Have significant negative effects on human health & the environment.
  • The most commonly encountered POPs are organochlorine pesticides, such as
    • Dichlorodiphenyltrichloroethane (DDT),
    • Endosulfan,
    • Polychlorinated biphenyls (PCB: resistant to extreme temperature & pressure. PCBs were used widely in electrical equipment like capacitors & transformers),
    • Dioxins (toxic by-products produced when organic matter is burned), etc.
  • DDT was widely used a few decades ago as an effective pesticide & insecticide.
  • It was later identified as POP, & its usage was phased out in almost all developed countries.
  • DDT is banned for agricultural use in India; however, it continues to be used for fumigation against mosquitoes (disease vector control) in several places in India In India.

Stockholm Convention on Persistent Organic Pollutants

  • It is an international environmental treaty.
  • It came into effect in 2004.
  • It aims to eliminate or restrict the production & use of persistent organic pollutants (POPs).

Chlorinated Hydrocarbons (Organochlorides)

  • CHCs are hydrocarbons in which one or more hydrogen atoms have been replaced by chlorine E.g., DDT (dichlorodiphenyltrichloroethane), endosulfan, chloroform, carbon tetrachloride, etc.

Applications of Chlorinated Hydrocarbons (CHC)

  • CHCs are used in the production of polyvinyl chloride (a synthetic plastic polymer used to make PVC pipes).
  • Chloroform, dichloromethane, dichloroethane, & trichloroethane are useful solvents.
  • These solvents are immiscible with water (not forming a homogeneous mixture when mixed with water) & effective in cleaning applications such as degreasing & dry cleaning.
  • DDT, heptachlor & endosulfan are were widely used as pesticides.

Effects of Chlorinated Hydrocarbons (CHC)

  • DDT accumulated in food chains & caused eggshell thinning in certain bird species.
  • In India, traces of DDT spray used three decades ago can still be found on the walls of homes.
  • DDT residues continue to be found in mammals across the planet.
  • In Arctic areas, particularly high levels are found in marine mammals.
  • The traces of persistent organic pollutant are found in the breast milk of several mammals.
  • In females, the concentration is lower due to the transfer of the compounds to their offspring through lactation.

Sharing is Caring !!

Newsletter Updates

Subscribe to our newsletter and never miss an important update!

Assured Discounts on our New Products!

Leave a Reply

Your email address will not be published. Required fields are marked *


Never miss an important update!