best ias books

Environment Pollution – Air Pollutants

Environmental Pollution

Primary Pollutants Persist in the form in which they are added to the environment for ex. DDT, Plastic
Secondary Pollutants Formed by interaction among primary pollutants viz. PAN by interaction of NOx & Hydrocarbons
Biodegradable Pollutants Waste products which are degraded by microbial action for ex. Sewage
Non-Biodegradable Pollutants Not decomposed by microbial action for ex. Plastic, Glass, DDT, Radioactive substances
Quantitative Pollutants Occur in nature & become pollutant when their concentration reaches beyond a threshold level for ex. CO2, NOx
Qualitative Pollutants  Do not occur in nature & are man-made for ex. fungicides, herbicides, DDT


Air Pollutants

Major Air Pollutants

 CO
  • By incomplete combustion of carbon based fuels, Automobile exhaust, Cigarette smoke
  • Combines with hemoglobin to form carboxyhaemoglobin, which is highly stable & reduces oxygen carrying capacity of blood
  • Slow our reflexes & make us confused & sleepy
CO2
  • Major greenhouse gas formed by respiration, burning of fuels, decomposition of lime, volcanic eruption
 CFCs
  • Released mainly from air conditioning systems & refrigeration
  • Detrimental to Ozone layer present in the stratosphere as CFC + UV >> Cl (Chlorine radicals which causes breakdown of Ozone)
Lead
  • Present in petrol, diesel, lead batteries, paints, hair dye products etc. (Affects children in particular)
  • Damages nervous system & cause digestive problems & in some cases causes cancer
O3
  • Formed when NOx particle from vehicle exhaust & volatile Hydrocarbons interact with each other in presence of sunlight
SPM
  • SPMs in air, when breathed in causes lung damage & respiratory problems
SO2
  • Produced from burning coal (60 %), mainly in thermal power plants + Petroleum products + in production of paper & smelting of metals
  • Major contributor to smog causing lung diseases
CH4
  • Mainly CH4 burns in fossil fuels + produced by burning of vegetation / rotting
Acid Rain
  • Ph < 5.6 (Rain with oxides of sulphur & nitrogen (SO2 & NO2)) – HNO3 + H2SO4
NOx
  • NO3-   Acts as a fertilizer to the soil
  • Automobile exhaust produces NO2 which damages plant leaves & retard rate of photosynthesis +  also causes red haze & lung irritation
Classical Smog
  • Occurs in cool humid climate
  • Chemically reducing hence called reducing smog
  • Smoke + fog + SO2

Ph value is a logrithmic index for hydrogen ion concentration in an aqueous solution, & each increasing Ph value diminish acidic nature of the solution by 1/10th

Photochemical Smog 
  • Occurs in warm, dry & sunny climate
  • Result from the action of sunlight on unsaturated HC & NOx produced by factories & automobile
  • Chemically oxidising hence called oxidising smog
  • Ozone + Acrolein + Formaldehyde + Peroxyacetyl Nitrate (PAN) are produced which cause serious health problems, severe plant damage, cracking of rubber & corrosion
  • Catalytic Converter – Prevent release of NO & HC to environment
GHGs
  • CO2, CH4, CFC, N2O, SF6, HFCs, PFCs, CCl4, CH3CCl3,  Water Vapour, O3
Formaldehyde
  • Mainly from carpets, particle boards & insulation foam  Causes irritation & allergies
 Radon
  • A gas naturally emitted by soil
  • Due to poor ventilation it is confined inside house & causes lung cancer

Fly Ash

  • Residue produced whenever combustion of solid material takes place, which rises with the gases in atmosphere & causes respiratory problems
  • Contains Aluminium silicates, SiO2 & Calcium oxide (CaO) + Toxic metals like lead, arsenic, cobalt etc.

 

Advantages of Fly Ash
  • Cement can be replaced by fly ash up to 35 % hence reducing cost of construction
  • Fly ash bricks are lighter in weight & offer high strength & durability
  • A better fill material for road embankments & concrete roads
  • Can be used in reclamation of wasteland, can increase crop yield & enhances water holding capacity of land

 

Sources of Air Pollutant Emission:  Industry > Transportation > Agriculture


Diseases By Air Pollutants

Yokkaichi asthma (SO2)

  • Burning of petroleum and crude oil releases large quantities of sulfur oxides which causes severe smog
  • Results in severe cases of chronic obstructive pulmonary disease, chronic bronchitis, pulmonary emphysema, and bronchial asthma

 

Pneumoconiosis / Black Lung Disease

  • an occupational lung disease caused by inhalation of coal dust, often in mines

 

Asbestosis

  • a lung disease, which leads to long-term breathing complications, caused by exposure to asbestos (No cure)

 

Silicosis

  • a lung disease that is caused by inhaling tiny bits of silica mainly by the workers working in silica industries or sand blasting sites

 

Emphysema

  • Breaking down of lung tissues due to air pollution & cigarette smoke leading to difficulty in expanding & contracting of lungs
India Yearbook English India Yearbook Hindi Economic Survey 2017

Leave a Reply

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

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>