Air quality basics

Air quality refers to the degree to which the air is suitable or clean enough for humans or the environment.

Good air quality means the air is free of harmful substances. Air quality is commonly measured with the Air Quality Index (AQI) which rates the amount of pollution in the air based on airborne concentrations of major pollutants – the higher the AQI value, the poorer the air quality. See details about the NSW AQI

In New South Wales we report AQI based on visibility and 6 major airborne pollutants:

  • ground-level ozone
  • carbon monoxide
  • sulfur dioxide
  • nitrogen dioxide
  • particulate matter as PM10 and PM2.5.

Air pollution refers to the release of pollutants into the air that are detrimental to human health and the environment. For reporting purposes, AQI values above 100 are deemed to denote polluted air. Poor air quality and health are closely linked. The World Health Organisation estimates that air pollution is the single largest environmental health risk, killing up to 1 in 9 people globally.

We monitor outdoor (ambient) air pollution in our monitoring network. Find out what pollutants we measure, their health effects, and measurement methods we use in our network.