Understanding air pollution

what causes air pollution

According to WHO, 92% of the world’s population live in areas where the air quality levels exceed prescribed WHO limits. To add to that, our own capital city of New Delhi has been topping the pollution charts. India’s air pollution level have overtaken even China (the country with the highest level of pollution). It therefore becomes imperative for us to understand a few things related to ‘air pollution’ like, what is air pollution, what causes it, and how can we as ordinary citizens make a difference.

The post below is an attempt on our part to help each one of us understand how a small effort at our end can make a difference.


What is pollution?

‘Pollution’, literally refers to contamination by foreign substances. The contamination could be of air, water, or soil amongst others and is usually responsible for interfering with the well-being and health of humans, marine and wild life, and mother earth.

Air pollution:

‘Air pollution’ a term that isn’t alien to us, is transboundary in nature i.e. it travels and affects areas beyond just that of its origin or source. Today, air pollution is considered one of the largest environment risks for humans. Responsible for 1 out of 8 deaths globally, it has been linked to health disorders like cancer, respiratory disorders, stroke, and heart diseases amongst others. While referring to air pollution, it is important to understand that pollution isn’t restricted to outdoor air, the air indoors can be almost as harmful as that outside. Do read our posts on ways to manage indoor air pollution – Purify indoor air with plants and NASA’s list of top 10 air purifying plants.


The pollutants in the air can be either natural i.e. caused by factors like dust and forest fires or synthetic, i.e. man made like smoke from burning fossil fuels. These can be in the form of gases, solids or liquid and can be either primary or secondary in nature:

  1. Primary: These are the ones that are directly released into the atmosphere from their sources
  2. Secondary: These are the ones that are formed due to the reaction of the primary pollutants with other elements in the atmosphere and include things like acid rain and smog

The pollutants that really pose a major threat to health are particulate matters, carbon monoxide, sulfur dioxide, nitrogen dioxide and ozone. Particulate matter, also commonly referred to as PM or particle pollution, are small sooty deposits that are suspended in the air and can be either solid or in the form of liquid droplets. These are the ones that form a blackish deposit on buildings and can be in varying sizes. While some of these particles can be seen with naked eye there are many others that can’t and when inhaled, these go and settle deep into the lungs, thereby causing various health issues. The main source of these in cities is known to be traffic fumes. (http://www.explainthatstuff.com/air-pollution-introduction.html).

Main contributors to air pollution in cities:

Of course burning of fossil fuels and emission of toxic gases from industries is hugely responsible for air pollution but there are multiple other factors that attribute to it:

  1. Fumes from vehicles: The fumes released from cars include toxic gasses like carbon monoxide, hydrocarbons, oxides of nitrogen, particulates etc. Needless to say, when inhaled these are responsible for multiple health issues. How do you avoid it? Car pool, use public transport like the metro, buy a bike, use a car sharing service like Uber, and if you must buy a car, make sure you buy the most fuel efficient and if possible, an electric car. We understand that electric vehicles aren’t a practical choice in India yet, but some options do make sense especially if you don’t have to drive long distances on a daily basis. If you drive your own car, check out our post on 5 simple ways to save fuel, which will help you reduce your carbon footprint daily.
  2. Fogging, fumigations, or use of other pesticides: With the health issues related to mosquitoes on the rise, as a natural resort most societies are opting for fogging. However, as per a report in the The Indian Express, fogging (a process that entails release of chemicals) was not only found to be ineffective in entirely killing mosquitoes (it is known to kill only adult mosquitoes and not the larvae) but it also ends up consuming tremendous amount of diesel. The fumes from diesel again end up releasing particulates into the air that as mentioned earlier are harmful for health.
  3. Sending waste to landfills: Today landfills are choking with garbage and a lot of that garbage includes plastic – something that can take thousands of years to decompose, and while it decomposes in landfills, it releases toxic gases like Methane. This is an example of improper waste management, and you can help by regularly composting.
  4. Burning waste: Another example of improper waste management – garbage is often burnt. The process itself sends out a concoction of chemicals into the air as smoke.

Curbing air pollution seems like an uphill climb, but all it needs is a few steps forward by each of us, rather than a thousand steps taken by one person.


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