The Sydney region extends from the southern boundary of the Wollondilly shire in the south to the northern boundary of the Hawkesbury and Wyong shires in the north, and includes the southern part of the Central Coast urban centre.
The Sydney region is a large basin with complex topography. The Hawkesbury basin is a sub-region on its western side, separated from the rest of the Sydney region by the Blacktown ridge. The north and south of the Hawkesbury basin have different patterns of pollutant concentration, largely because the sea breeze usually blows from the northeast. It is therefore useful to consider the Sydney region as having three sub-regions: east, north-west and south-west.
Monitoring and reporting
We monitor air quality in each of Sydney’s sub-regions. The monitoring network has five stations in the east, four in the north-west and six in the south-west. Download the network site information (XLSX 31KB).
Using data from these stations, we provide hourly values of pollutant concentrations and an Air Quality Index (AQI).
For details of our monitoring program, see the National Environment Protection Measure air-monitoring plan for New South Wales (PDF 2.4MB).
You can also find more air-quality information for the Sydney region in OEH’s annual air quality monitoring reports.
Early studies of air quality in the Sydney region included the Sydney Oxidant Study (in the late 1970s), the Metropolitan Air Quality Study (MAQS, 1992–1995) which focused on photochemical ozone and fine-particle pollution, and the Ambient Air Quality Research Project (1996-2001) which studied air toxics.
The Air Pollution Economics: Health costs in the Greater Sydney Metropolitan Region (PDF 394KB) study published in 2005 estimated the cost to health of ambient air pollution.
The Ozone State of Knowledge study, completed in 2010, consolidated and expanded knowledge on ground level ozone pollution and events contributing to high ozone levels in the Sydney, Illawarra and the lower Hunter regions.
Recent research studies which have expanded the evidence base on the composition and sources of particle pollution in Sydney include the Sydney Particle Study (completed in 2013) and the 15-year Sydney Particle Characterisation Study (published in 2017).
Research into trends, sources and impacts of air pollution is ongoing as part of the Sydney Air Quality Study. Air quality forecasting for Sydney is progressively being improved as part of the Enhancing Air Quality Forecasting in NSW research program.
The Air Emissions Inventory for the Greater Metropolitan Region in NSW, which is updated every five years, provides detailed information on sources of air emissions in Sydney.