Environment and Environmental Problems Part-2

Food Web

  • It is formed by interconnections of different food chains.
  • It shows in graphic form "Who Eats Whom" in an ecosystem.
  • Due to the interlinking of food chains, food webs are never straight.
  • The food web offers additional pathway for food availability. In the event that one species is wiped out, the predator could feed on a different species.


  • The concentration of harmful chemical increases with every next trophic level in a food chain. It is called Bio-magnification
  • The human body accumulates these substances at the highest quantity. Since humans occupy the top level in any food chain.

Environmental Problems

  • Changes in environment affect us and our activities change the environment around us. Environmental problems caused by humans:
  • (a) Depletion of the Ozone Layer and waste disposal.
    (b) Pollution due to mismanagement of waste disposal.

Ozone Layer

  • High UV radiation breaks down oxygen into oxygen atoms. These oxygen atoms when combine with oxygen, they form ozone.

Depletion of Ozone Layer

  • The ozone layer protects the Earth from the sun’s ultraviolet (UV) radiation.
  • In 1985, it was discovered that the ozone layer's thickness over Antarctica had dropped. This is defined as ozone depletion and was termed as Ozone hole. 
  • The overuse of chlorofluorocarbons in aerosols, air conditioners, and other products leads to ozone depletion.
  • Ozone is formed as a result of a following photochemical reaction.

  • Ozone depletion would allow ultraviolet rays to enter the earth's atmosphere, resulting in blindness, skin cancers, and genetic abnormalities.

Reason of Ozone Depletion

  • Ozone depletion in the upper atmosphere was caused due to excessive usage of CFCs (Chloro Flouro Carbon), a synthetic, inert chemical, such as Freon, which are used as refrigerants and in fire extinguishers.
  • A single chlorine atom can destroys 1, 00,000 Ozone molecules.
  • A great work was done by U.N.E.P. (United Nations Environment Programme) in negotiating the Kyoto Protocol, which demands that all nations' CFC production must stop at levels last seen in 1986.

Garbage Management

  • Involves all the activities and actions required to manage waste from its inception to its final disposal.
  • Ensures environmental best practices are followed along with proper monitoring and regulation.

Methods of Waste Management

  • Incineration: Burning of waste on high temperature to form ash is called incineration. This process is carried out in an incinerator. Incineration is used to destroy household, chemical and biological wastes.
  • Open dumping: A conventional method in which solid wastes dumped in selected areas of a town. It actually cause pollution
  • Land fillings: Wastes are dumped in low living areas and are compacted by rolling with bulldozers
  • Composting: Organic wastes are filled into a compost pit (2m × 1m × 1m). It is then covered with a thin layer of soil. After about three months the same garbage filled inside the pit changes into organic manure.
  • Recycling: The solid wastes are broken down into its constituent simpler materials. These materials are then used to make new items. Even non-bio degradable solid wastes like plastic, metal can be recycled.
  • Reuse: A very simple conventional technique of using an item again and again. For example; paper can be reused for making envelops, etc…