Do you know more than 90 per cent of the world is living in places where the air pollution levels exceed the levels set by the World Health Organisation? The highest burden of air pollution is on the South East Asian and Western Pacific regions.
 
Air pollution is a mixture of microscopic particles and gases that can be either natural or artificial. These microscopic particles and the gases affect humans in many ways. Air-pollution can lead to respiratory and cardiovascular diseases and even deaths. Researchers have also established a strong connection between air pollution and the incidence of lung cancer.
 
Air pollution does not always mean 'outdoor pollution'. What many have not yet realised is that pollution can be 'indoor' as well. Household (indoor) air pollution is also dangerous and can lead to a range of diseases. It should also be noted that indoor pollution is one of the top five causes of premature deaths globally. Excessive use of artificial fragrances, sprays like aerosols, paints are the major reasons for increasing indoor pollution. 
 
How does air Pollution affect health?
Particulate matter (PM 10 and PM 2.5) is a complex pollutant and contains a variety of components in variable concentrations. Ozone (O3), Carbon Monoxide (CO), Nitrogen oxides (NOx) and Sulphur Dioxide (SO2) along with the Particulate Matter are the top five air pollutants.
 
When we inhale polluted air, particulate matter in the air like dust, aerosols and soot from fuel emissions and burning reach the alveoli or the air sacs in our lungs and then make its way into the bloodstream leading to inflammation.  Heart, blood vessels and brain are the first to face the brunt of air pollution.
 
Depending on the period you are exposed to air pollution other complications arise. Short- and long-term exposure to air pollution can lead to premature birth, low birth weight, dementia, diabetes and others.
 
Ozone, sulphur dioxide and other gases in association with other pollutants in the presence of sunlight can lead to chest congestion, shortness of breath and other respiratory complications.
 
Who should be weary of Air Pollution?
Air pollution affects everyone. But babies, children, pregnant women and the elderly are more susceptible to the adverse effects of air pollution. Children are more prone as their lungs are in the developing stage. Also, children spend more time outdoors and are more susceptible to flu and cold. When pregnant women are exposed to air pollution the chances of the foetus getting affected is very high. On the other hand, the elderly who have pre-existing health disorders are more susceptible to air pollution.
 
Many are living in a condition that increases their exposure to air pollution like residing in slums, industrial areas and at places which do not have proper ventilation.
 
Tips to protect yourself from Air Pollution
1. Download an app that will give details of air pollution in your area. When the pollution levels are high, you can prefer staying indoors and avoid going out.
2. Do not allow indoor smoking and fight for smoke-free public places. 2.
3. Do not exercise outdoors when the pollution levels are high.
4. Switch to public transport and reduce the usage of cars and bikes. Carpooling is also a good idea.
5. Never burn wood, trash or plastic as they are major pollutants to the air.
6. If you face any respiratory related problems consult your doctor. 

(The writer is consultant pulmonologist, Columbia Asia Hospital, Hebbal. Views expressed are his personal.)