Air Pollution Facts

The quality of air has been under a lot of discussion since Diwali. Delhi was shrouded in a thick blanket of toxic smog with the air quality index crossing the 1,000 microgram mark for the first time in South Delhi. The air quality index (AQI) remained 21 times higher than the recommended levels (which is 25 μg/m³ for a 24-hour mean) for more than 4 days.

“Air pollution is a major contributing factor in the deaths of around 600,000 children under five every year — and it threatens the lives and futures of millions more every day,” UNICEF executive director Anthony Lake said in a press release post Diwali. Delhi’s air quality index is read between poor, very poor and unhealthy throughout the year, any source of additional pollution will put the health of its residents in severe harm’s way.


What are the basics we need to know about air pollution and air quality to become aware about the situation?

First things first, we need to know the difference between clean air and polluted air. Presence of any substance with harmful or poisonous effects in the air causes air pollution. In urban areas, most common form of air pollutants are from vehicles and burning of wood or biofuel. We can be exposed to two kinds of air pollution, outdoor air pollution or ambient air pollution and indoor air pollution or household air pollution. Outdoor air pollution is caused by vehicular exhaust, trash burning, emissions from coal fired power plants, dust from construction sites, agricultural waste burning, and household biomass burning. The major source of indoor air pollution comes from cooking and heating burning wood, cow dung, coal and other biomass fuels. Household chemicals, pet dander, mold, tobacco smoke are also some of the major sources of household air pollution.

How do we know when the air is polluted?

Daily reporting of air quality is done using the AQI. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. AQI is published by government agencies to communicate to the public, the current and forecasted levels of air pollution. As the AQI increases, an increasingly large percentage of the population is likely to experience severe adverse health effects.


Why is air pollution a problem?

Air pollution is linked to a number of health issues, which includes coughing, wheezing, reduced lung function, asthma attacks, COPD (Chronic Obstructive Pulmonary Disease), strokes, and adverse pregnancy outcomes. Long-term exposure to high levels of air pollution can also cause cancer. Poor quality of air is very dangerous to vulnerable populations like children, the elderly, and those with pre-existing conditions. People with cardio-vascular disease (pre-existing health issues with heart), lung disease including asthma, children under the age of 5 and elderly above 50 are at a greater risk. New and expectant mothers should also take precautions to protect the health of their babies as exposure to air pollution has impacts on the fetus. Apart from the direct impact on human health, air pollution can cause damage to animals, trees, plants, crops and water sources in the environment, and also be responsible for damaging buildings and other structures.

What measures can we take to reduce the harmful effects of air pollution?

The first step is to stay indoors and reduce outdoor activity as much as possible, especially when AQI is unhealthy. In addition to staying indoors, reducing exertion can reduce the amount (dose) of air pollutants inhaled. Outdoor air pollution levels change day to day and almost every hour, so in order to effectively adjust our behavior to reduce exposure and risk, we must know when and where air pollution levels are higher than recommended. Air monitoring stations across many metro cities like Delhi, Gurgaon, and Pune measure the AQI and share the information with the public. This information can be found at and should be used to ensure that children and elderly limit their outdoor time during unhealthy levels. Other measures to reduce exposure include using anti-pollution masks, having indoor plants which can improve the quality of the air, and using air purifiers to clean the air.


The Do’s and Don’ts – On high air pollution days

autoAvoid auto-rickshaws.

Though a cost-friendly mode of transport, savings in the short-term can prove to be harmful in the long run. Research done by IIT-Delhi and University of California, Berkeley, shows that travel by an auto rickshaw leads to 20 times more exposure to ultrafine particles as compared to travel in a closed environment like a car. This is especially important for children, elderly, and patients with existing health conditions.

trafficAvoid peak traffic times.

Beating traffic is more than just about avoiding traffic jams. Pollution levels are highest during peak times. Additionally, the idling of engines and stop and go traffic causes an increase in particulate matter (PM10).

walkLimit your night time and early morning outdoor activities.

If you like to go out running or for your morning walk in the morning, be aware that you are being exposed to high levels of pollutants. This is because night time cool temperatures create an atmospheric inversion effect, which traps the polluted air under a blanket of warm air and prevents it from escaping.

How can we help in addressing the air pollution crisis?

We can start the initiative from our homes – by conserving energy and using more energy-friendly products. Carpooling, using public transport, and bicycles will reduce our contribution to vehicular pollution. Using environment-friendly paints and cleaning products whenever possible will reduce the release of toxic chemicals into the air; as will preventing burning of dry leaves, garbage, wood, rubber or plastic. Discouraging the use of fire crackers in festival season and planting more trees can also help.

The first step towards a cure is to understand the issue, find ways to address them and finally take action. “Change starts with you, but it doesn’t start until you do”. So inform your family and friends on how air pollution is a major health threat and how together we can reduce it.

2 responses to “Air Pollution Facts”

  1. Thank you for raising such a topical issue on the CEH Blog. Air pollution remains a silent threat which puts us all at risk. I have enjoyed seeing the responses to the call for improving air in Delhi at the PHFI Gurgaon office foyer and look forward to these responses being collated into a follow up post for the blog. It would be interesting to see how the PHFI members propose fighting the malady in the air!

    Great to see the blog up and running. Please provide options like Feedburner or other email subscription systems which allow us to sign up for blog post updates.

  2. Isabella says:

    I couldn’t resist commenting. Exceptionally well written!

Leave a Reply

Your email address will not be published.