The Air Quality Index compiled by the Victorian Environment Protection Authority describes the concentration of various pollutants relative to environmental standards. The lower the index is, the better the quality of our air. The index is available for four areas in the Port Phillip Region (East, West, City and Geelong) and the Latrobe Valley.
The Air Quality Index is made up of separate indices for each pollutant. Two of these are presented here - Visibility Reduction, and Ozone. The Visibility Reduction Pollutant Index gives a measure of the amount of fine particles in the air. These particles scatter light and reduce how far we can see. The Ozone Pollutant index tracks the amount of ozone associated with summer smog, which is harmful to human health.
In the data tables, air quality associated with these pollutants is classified as Very Good, Good, Fair, Poor or Very Poor. Incidents of Poor visibility are generally higher during the cooler months of autumn and winter (from March to August), whereas ozone levels are generally higher during the summer (from December to February). However, during periods of smoke from bushfires or planned burns, there may be a lot of particles in the air, causing the Visibility Reduction index to reach the Poor or Very Poor category during summer or autumn.
Air pollution varies a great deal from hour to hour, day to day and season to season, according to weather and pollution sources. Daily forecasts for the next day’s air quality in Melbourne are available in major newspapers and on the EPA website.
More information on the air quality index can be found by visiting the EPA website:http://www.epa.vic.gov.au/air/bulletins/aqindex.asp
View underlying table as an Excel spreadsheet: Download Air quality, By Region from the Downloads Page.