In 2015 the former Office of Environment and Heritage conducted a study on air quality trends in the Illawarra. This study is documented in the report titled Air Quality Trends in the Illawarra (PDF 4.6MB).
This report describes how air quality has changed in the Illawarra over the past two decades. It draws on data from the department's air quality monitoring network, emission inventories, air quality modelling and particle speciation studies. It also describes the local airshed and identifies areas of future research to expand our understanding of air pollution and its impacts.
What did the report find?
Good air quality by international standards
Air quality in the Illawarra is similar to other Australian cities and is generally good by international standards. Over the past 5 years (2010-2014) air quality in the Illawarra was 'very good or good' for 78% to 85% of the time, 'fair' for 13% to 20% of the time, and 'poor or worse' for 1% to 7% of the time. Information about how these Air Quality Index categories correspond to different levels of health risk is available from NSW Health.
Poor air quality generally occurs as a result of high levels of particle or ozone pollution. Years affected by bushfires, dust storms and high temperatures usually have the greatest number of 'poor or worse' air quality days.
Improving air quality
Air quality in the Illawarra has been generally improving over time. Carbon monoxide, nitrogen dioxide, sulfur dioxide and lead levels have decreased since the 1990s and are all consistently below national standards.
Particle and ozone levels
Particle (PM10 and PM2.5) and ozone levels vary from year to year, often higher in hotter, drier years. They can exceed national standards from time-to-time, posing health risks.
Health effects from particle and ozone pollution are known to occur at levels below the current national standards, so continued efforts to reduce air pollutants will provide additional health benefits.
Air quality affected by regional and other sources
Air quality in the Illawarra is affected by sources in the region as well as sources outside the region.
High ozone levels can occur due to the combined effect of local emission sources and air pollutants transported by wind down the coast from Sydney.
Bushfires outside the region can contribute to high ozone and particle levels, as occurred in the October 2013 bushfires.
Regional dust storms are responsible for some of the highest peaks in particle pollution, as occurred in the September 2009 dust storm which affected much of New South Wales.
Sources of air pollution
Major sources of air pollution in the Illawarra include:
- EPA-licensed industry,
- household activities (notably residential wood heating),
- commercial businesses,
- road transport, non-road equipment and transport (construction and mining equipment, rail locomotives and ships),
- natural sources (such as emissions from forested areas, bushfire smoke and wind-blown dust from exposed areas).
You can learn more about sources of air pollution in the Illawarra by using the EPA Air Emissions in My Community web tool.
Future air quality
Future air quality in the Illawarra will be affected by population growth, changes in transport and industrial activity levels, and changes in climate.