- Burning of solid fuels like coal, wood
and cow dung.
- Dust mites, molds and pollens
- Smoking and usage of pesticides
- Heating appliances and also from
According to WHO data, more than 4
million people prematurely die from illness because of cooking with solid
fuels. The data further says that over 50% of deaths which happens prematurely
among children under 5 are due to indoor air pollution.
Outdoor Air Pollution:
Outdoor air pollution occurs when any
toxic substances, chemical or biological, contaminates the ambient outdoor air.
A common example of outdoor air pollution is smog which is nothing but a
combination of smoke and fog.
Outdoor Air Pollution Is Mainly Caused By:
- Emission of smoke from vehicles
- Smoke from industries
- Toxic fumes from solvents
- Forest fires
- Burning of fossil fuels
- Volcanic eruptions
- Decaying of plants and animals
- Chemical used in farming such as fertilizers,
WHO says 3.7 million deaths occurs due to outdoor air
pollution globally. 88% of these deaths occur in low and middle income
countries which contributes 82% of world population.
Pollutants are the agent which causes
pollution and can be either or combination of gaseous pollutants, odor and
Suspended Particulate Matters (SPM). Pollutants are generally categorized into
primary pollutants and secondary pollutants. While the former is emitted
directly into atmosphere and the latter is the resultant product when primary
pollutants reacts with environment.
Examples of Primary Pollutants and Their Sources Are:
- Carbon Monoxide (CO) : volcanic activity;
Combustion of coal, oil and gas
- Oxides of Nitrogen (NOx): Fuel
combustion and wood burning; Industrial boilers; Agriculture soil because of
fertilizers and also from livestock manure
- Oxides of Sulphur (SOx):
Thermal Power Plants.
- Toxic metals like lead, mercury ,
- Volatile organic compounds((VOC): Methane, Propane
- SPM : Ash, dust, pollen, cigarette
When primary pollutants react with
other elements in atmosphere and causes a chemical reaction then it is
Sulphuric acid H2SO4
Ozone which is at ground level is
formed from the reaction of nitrogen oxides and VOCs
pollution poses severe health risks in the lives of human being. Some of them
are Asthma, nausea, headache. Bronchitis, throat irritation and cough, skin and
eye rashes and it is also a source for major illness like cancer, birth
defects, Miscarriages , damage in nervous system, cardiovascular disease,
Toxic chemicals and gases causes acid
rain which damages natural resources. Over use of fertilizers causes deposition
of nitrogen. Crop production may be reduced and also it is a serious threat to