Qualité de l’air à Perth

Is Perth polluted?

The capital city of Western Australia, located on the south-west coast of the state, Perth is Australia’s 4th most populated city, following Sydney, Melbourne, and Brisbane. Like much of Australia, Perth experiences generally healthy air quality most of the year round, in comparison to global locations. However, Perth can also experience occasional short-term, extreme air pollution episodes most often caused by wildfires and dust storms. Historically, the main pollutants of concern within Perth have been photochemical oxidants (measured as ozone), and particulate matter pollution. This is because these two pollutants most often exceed the Australian air quality standards, known as the National Environment Protection (Ambient Air Quality) Measure (Air NEPM). Ozone is a gaseous secondary pollutant, meaning that it is not produced directly from any one source, but rather it is formed through chemical reactions between other airborne pollutants known as ‘precursors’, such as nitrogen oxides (NO_x) and volatile organic compounds (VOCs), in the presence of sunlight. Accordingly, high Perth ozone levels are most likely to occur during hot and sunny conditions. Perth’s ozone levels are most often highest during the summer months, while haze from particulate matter is most commonly high during the colder winter months, particularly when domestic wood heaters are being used with higher demand.¹

Live air quality information can be viewed in the Perth air quality map at the top of this page, which also contains real-time wildfires updates. These, along with a 7-day Perth air quality forecast are available to follow on-the-go using the IQAir AirVisual air pollution app.

What are the health effects of air pollution in Perth?

Exposure to high levels of ozone can cause short term irritation of the airways, and minor lung function changes; elevated ozone concentrations have also been associated with increased hospital admissions, and premature mortality.² Exposure to particulate matter, which describes miniscule airborne particles measuring less than 2.5 or 10 microns in diameter (abbreviated as PM2.5 and PM10 respectively), are particularly hazardous to human health due to their microscopic size enabling them to penetrate deep into the human system when inhaled. PM can travel into the lungs, and tiny PM2.5 can go further into the bloodstream, causing a range of health effects. Exposure to PM pollution can cause short-term effects, including irritation of eyes, nose and throat, and aggravation of existing conditions such as asthma; while long-term effects can increase a risk of cardiovascular and respiratory disease, such as chronic obstructive pulmonary diseases (COPD) like emphysema and bronchitis, lung cancer, and increased risk of premature mortality.

What are the main sources of Perth air pollution?

The two main causes of air pollution in Perth are vehicle emissions and smoke, which may come from activities including bushfires and domestic wood heaters.² These pollution sources are anticipated to intensify over time, along with predicted population growth in Perth increasing the demand for both heating and vehicular transport. In addition, as global temperatures increase as part of climate change, the conditions will become increasingly favourable to severe wildfires, increasing the risk of severe particulate smoke pollution.

Is Perth threatened by fire?

Like the rest of Australia’s air quality, Perth and Western Australia are vulnerable to experiencing wildfires on an annual basis. The time at which various parts of Australia are most vulnerable to fires varies with seasonal weather patterns; in general, northern Australia is at highest risk of fires during the dry season, usually through winter and spring, while southern Australia, the season for bushfires peaks during summer and autumn. Given Perth’s southwestern location, is at highest risk during the spring and summer months.³

Australia experienced particularly severe wildfires across the country during the summer of 2019-2020, following several months of drought, low rainfall and record breaking temperatures. Perth was not spared, and experienced an out-of-control bushfire in mid-December 2019 north of Perth. The fire burned through over 11,000 hectares of land, leading to evacuations of the area.⁴ Despite the highly destructive nature of bushfires to both people and natural and built landscapes, experts estimate that the health impacts from smoke exposure resulting from fires had a much larger impact on human wellbeing than the fires themselves. A study in the Medical Journal of Australia estimated that while 33 people were reported as tragically killed by the Black Summer’s bushfires, a further 417 premature deaths may have been caused by the smoke, along with 3,151 additional hospitalisations for cardiorespiratory problems, and 1,305 additional attendances for asthma attacks.⁵

What is Perth doing about air pollution?

Western Australia’s air quality is managed by the state government’s Department for Environmental Regulation. In 2000, Perth’s Department of Environmental Protection published its Perth Air Quality Management Plan (AQMP), which was intended to govern Perth’s air quality over the subsequent 30 years.⁶ Following the Plan’s publication, the Western Australian Government and Air Quality Coordinating Committee have published regular scorecards on the city’s progress regarding the AQMP. Initiatives being carried out as part of the Plan’s execution, include the “Burnwise” campaign, which promotes awareness and information about the efficient use of domestic wood heaters, to minimise smoke emissions; promoting sustainable transport over private vehicles, such as cycling and walking through various events and campaigns; and supporting research programs into the effects of air pollution on health.⁷

The Western Australia government also runs a network of 15 air quality sensors state-wide, 9 of which are installed within the Greater Perth Region. These 9 air monitoring stations include those in Perth’s suburbs of Caversham, Duncraig, Quinns Rocks, South Lake, Swanbourne and Wattleup, as well as the southern city of Mandurah, city of Rockingham, and the more inland station Rolling Green.⁸ The WA Government monitors air quality within its state, to check progress against Australia’s national air quality standards, known as the National Environment Protection (Ambient Air Quality) Measure (Air NEPM). The NEPM standards provide short term (such as 24-hour) and annual target levels that various air pollutants should not exceed, to minimise Australians’ health risks from pollution exposure.

The WA Government then reports these measurements to the public using a Perth Air Quality Index, which follows the wider Australian air quality index guidelines. The Perth AQI expresses pollutant levels as a percentage of their respective standard: for example, an AQI of 100 represents the maximum allowable level of that pollutant under its NEPM standard, and 200 AQI would represent an exceedance twofold. Where multiple pollutants are measured at a single location, the pollutant with the highest AQI will dictate that location’s overall AQI indicator. The Perth AQI scale is color-coded, to further help quickly communicate air quality’s health hazard at a glance. 0-33 represents “Very Good” air quality (blue), while 200+ represents “Extreme” air pollution.⁹

+ Article resources

[1] Department of Environment, Perth. “Research on Health and Air Pollution in Perth”. Department of Environment Regulation website, May, 2003.
[2] Western Australia Government Department for Environmental Regulation. “Perth Air Quality Management Plan”. WA Government DER website, December, 2000.
[3] Australian Government Bureau of Meteorology. “Bushfire weather”. Australian Government Bureau of Meteorology website, n.d.
[4] Helen Davidson. “Western Australia bushfire out of control as temperatures expected to surge above 40C”. The Guardian, December 14, 2019.
[5] John Pickrell. “Smoke from Australia’s bushfires killed far more people than the fires did, study says”. The Guardian, March 20, 2020.
[6] Western Australia’s Department of Environmental Protection. “Perth Air Quality Management Plan”. Western Australia Government website, December, 2000.
[7] Government of Western Australia & Air Quality Coordinating Committee. “Perth air quality management plan report card (2012-13)”. WA Government website, 2014.
[8] Government of Western Australia Department of Water and Environmental Regulation. “2019 Western Australian air monitoring report”. WA Government Department of Environmental Regulation website, October 2020.
[9] Government of Western Australia. “Air quality index”. Government of Western Australia website, n.d.