The AQI or Air Quality Index is very effective tool to communicate the air quality status in terms that are easy to understand by the people. This is the transformation of above stated pollutants into the value of single number and colour and nomenclature.

The Index is centered around five chief pollutants:

  • Particulate Matter
  • Ozone
  • Nitrogen Dioxide
  • Carbon Monoxide

A monitoring station should be able to give you the concentration of a particular pollutant at that moment in time, and its average over a period of time – for CO and O3, the average is taken over eight hours, while for the other three, it is a 24-hour average. The unit of measurement is microgram (or milligram in the case of CO) per cubic meter.

India has set standards for what it thinks are appropriate warnings for a particular level of pollutant. Here’s what the code is:


Air Pollution in India: Real-time Air Quality Index Visual Map:

To avoid Unhealthy Air:

You can take simple steps to reduce your exposure to unhealthy air. First, you need to find out whether AQI levels are a concern in your area. This can be done by looking in website AIRNow and also from EnviroFlash or local media. If the AQI for ozone, particle pollution, carbon monoxide, or sulfur dioxide is a concern in your area, you can learn what steps to take to protect your health by checking the charts on the following pages. Two important terms you will need to understand are:

  • Prolonged exertion. This means any outdoor activity that you’ll be doing intermittently for several hours and that makes you breathe slightly harder than normal. A good example of this is working in the yard for part of a day. When air quality is unhealthy, you can protect your health by reducing how much time you spend on this type of activity.
  • Heavy exertion. Breathing hard because of intense outdoor activities. When air quality is unhealthy, you can protect your health by reducing how much time you spend on this type of activity, or by substituting a less intense activity—for example, go for a walk instead of a jog. Be sure to reduce your activity level if you experience any unusual coughing, chest discomfort, wheezing, breathing difficulty, or unusual fatigue.

What next?

CSE believes that the newly-released Air Quality Index is an important step forward to build awareness and protect public health.

Expansion and improvement of air quality monitoring network across cities to generate real time air quality data is one priority. Besides this, ensuring good quality monitoring, disseminating daily air quality index and health advisory widely through print, electronic media as well as other communication channels will be needed to make the Index effective. Other measures demanded by CSE include implementation of pollution contingency measures to bring down peak pollution levels during severely polluted days. “Cities need pollution emergency measures to be implemented when air pollution level remains elevated for consecutive days to bring down the peak exposure levels,” says the think tank.

According to CSE, short and medium term action plans are needed in all cities to meet air quality standards and initiate a public awareness campaign and pollution emergency measures are needed to address this public health crisis.

The global story

With this step forward, India has joined the global league of countries like the US, China, Mexico, France and Hong Kong that have implemented smog alert systems. These countries not only issue smog alerts, but also implement pollution emergency measures to bring down the peak pollution levels. Indian cities need the same roadmap.

Key measures taken by some countries to deal with air pollution: