Air Pollution In Australia: Where Is It Worst?

Australia's air quality is generally considered to be among the cleanest in the world, with cities like Hobart, Darwin, and Canberra topping the list. However, the country is vulnerable to short-term extreme pollution spikes due to natural factors such as bushfires and dust storms. Human-influenced factors, such as combustion in vehicle engines, road traffic, industrial processes, power generation, and domestic wood heaters, also contribute significantly to air pollution in Australia. Sydney, one of Australia's most populous cities, has been ranked low in terms of air quality, with the western suburbs of Sydney, particularly areas like St Marys and Campbelltown, experiencing high levels of pollution. Other cities like Melbourne and those in New South Wales, especially Armidale and Tamworth, have also faced air quality issues.

Sydney and Melbourne are among the cities with the worst air pollution

Australia's air quality is generally considered to be among the cleanest in the world. However, the country is vulnerable to short-term extreme pollution spikes caused by bushfires and dust storms. During these episodes, some parts of Australia have temporarily experienced some of the worst air quality globally.

In 2019, 13 of the top 15 most polluted cities for annual PM2.5 concentration were in New South Wales. That year, Armidale was Australia's most polluted city for PM2.5 pollution, followed by Tamworth and Canberra. Sydney, the capital of New South Wales, is also susceptible to poor air quality.

Melbourne, the capital of Victoria, experienced extremely high levels of air pollution during the devastating Australian bushfires of 2019-2020. On January 14, 2020, Melbourne's air pollution briefly registered as the highest worldwide, with hazardous levels of PM2.5 peaking at 470 μg/m3. During that same day, the city's PM2.5 levels recorded a 24-hour average of 234 μg/m3, exceeding the shared 24-hour exposure limit of the World Health Organization (WHO) and the Australian government by almost ten times.

Melbourne's annual average concentration of fine particulate matter (PM2.5) was a relatively low 6.5 μg/m3 in 2019, meeting both Australian and World Health Organization annual targets. However, the city is not immune to poor air quality, as it experiences relatively low but persistent levels of various pollutants year-round. Common outdoor air pollutants in Melbourne include carbon monoxide (CO), sulphur dioxide (SO2), nitrogen oxides (NOx), ozone (O3), and particulate matter (PM2.5 and PM10).

Hobart, Darwin and Canberra have the cleanest air

Australia's air quality is generally among the cleanest in the world, although the country is vulnerable to short-term extreme pollution spikes due to bushfires and dust storms. However, even at relatively low levels, air pollution can have serious health impacts, including decreased lung function, increased respiratory symptoms, and a higher risk of cardiovascular disease, lung cancer, shortened life expectancy, and premature death.

In 2019, 13 out of the top 15 most polluted cities for annual PM2.5 concentration were in New South Wales, with Armidale, Tamworth, and Canberra being the top three. Despite this, Canberra's air quality is considered relatively clean compared to other state capitals, with an average PM2.5 concentration of 15 μg/m3 in 2019, which is below the national standard.

Hobart, the capital of Tasmania, also maintains relatively clean air. While specific data on the city's air quality is limited, Tasmania's isolated location contributes to its overall clean air.

Darwin, located on the northern coast of Australia, experiences a tropical monsoon climate with a dry season from May to October and a wet season from November to April. The city generally enjoys healthy air quality throughout the year, but like the rest of the country, it is vulnerable to short-term air pollution spikes due to bushfires and dust storms. Darwin's main pollutant of concern is particulate matter (PM), specifically PM2.5 and PM10, which can have significant health impacts even at low concentrations. According to the Northern Territory's Environment Protection Authority (EPA), Darwin averaged a PM2.5 concentration of 9 μg/m3 in 2019, slightly exceeding the national air quality standard of 8 μg/m3.

In summary, while Canberra, Hobart, and Darwin experience relatively clean air compared to other parts of Australia, they are still susceptible to short-term air pollution spikes due to natural and human-made sources, including bushfires, dust storms, vehicle emissions, industrial processes, and domestic wood heating.

Bushfires and dust storms cause extreme pollution spikes

While Australia's air quality is generally good, the country is vulnerable to short-term extreme pollution spikes caused by bushfires and dust storms. During these events, some parts of Australia have temporarily experienced some of the worst air quality in the world.

Dust storms are relatively common in Australia, typically occurring during spring when cold fronts arrive. Some dust storms are more extreme than others, such as Sydney's "Red Dawn" in 2009, which impacted air quality beyond Sydney. The thick dust reduced visibility below 1 km for several hours, peaking at 400 m. It caused the closure of roads and disrupted flights and ferries.

Bushfires, especially during the summer fire season, are another key reason for pollution spikes in Australia. These fires emit smoke and harmful particles into the air, degrading air quality. For example, during the “Black Summer” bushfires of 2019-2020, the air pollution was 15 times worse than levels considered safe by the WHO. This was linked to 429 premature deaths and more than 3000 hospitalisations due to smoke-induced breathing problems or heart issues.

Following the severe 2019-2020 summer bushfires, the Queensland air quality monitoring network was expanded to provide more communities with access to local particle measurements during bushfire smoke episodes. Queensland Health has developed recommended health actions based on particle levels to inform the community about protecting their health during smoke or dust events.

Overall, despite Australia's generally good air quality, bushfires and dust storms can cause extreme pollution spikes with significant health impacts, including decreased lung function, increased respiratory symptoms, and an elevated risk of cardiovascular disease, lung cancer, shortened life expectancy, and premature death.

Air pollution is worse in areas where Australians on lower incomes live

Australia's air quality is generally considered to be among the cleanest in the world. However, the country is vulnerable to short-term extreme pollution spikes caused by natural events such as bushfires and dust storms. These events can temporarily push some parts of Australia into experiencing some of the worst air quality globally.

While Sydney and Melbourne, two of Australia's biggest cities, are often cited as having the worst air pollution, it is the people in lower-income areas that are disproportionately affected by air pollution. This is due to several factors, including the concentration of major pollutant emitters, such as power plants, factories, and highways, in low-income communities. Decision-makers know that these communities are unlikely to have the resources or political power to oppose the location of these emitters. Additionally, low-income neighborhoods offer financial incentives for industries, such as cheaper land, low-cost labor, and better transportation access.

The health impacts of air pollution can be severe, even at relatively low levels of exposure. People with asthma are particularly vulnerable to air pollution, and they can experience symptoms such as respiratory issues almost immediately. However, the effects of air pollution on other diseases, such as cardiovascular disease and cancer, may not manifest until years or decades later.

Western Sydney, for example, has been identified as an area with high pollution levels, largely due to the geographical peculiarity of wind patterns. The wind carries particulate matter generated in the metropolitan Sydney basin down towards south-west Sydney, where it settles during the night. This creates a compounding health risk for the residents of that area, who are predominantly from lower-income households.

To address these disparities, experts suggest better land use and urban planning. For instance, childcare centers should be located away from arterial roads to reduce children's exposure to air pollution. However, some solutions may inadvertently create new problems, such as moving childcare centers to areas with higher rents or smaller land parcels.

Western Sydney has high pollution due to diesel trucks

Sydney has been ranked as the Australian city with the worst air quality, falling behind other major cities such as London and Beijing. While bushfires and dust storms are significant contributors to poor air quality across Australia, diesel trucks are a major source of air pollution in Western Sydney.

Sydney, being one of Australia's most populous cities, experiences high traffic volumes, which contributes to its poor air quality. Diesel trucks, in particular, emit a cocktail of particulate matter, with 80-95% classified as ultrafine PM2.5 particles. These fine particles, which are smaller than a human hair, can have severe health impacts. The World Health Organization (WHO) states that no amount of exposure to PM2.5 is safe, and it has been linked to respiratory issues, cardiovascular disease, lung cancer, and even premature death.

Western Sydney, especially Melbourne's western suburbs, experiences significant truck pollution. Trucks use main residential streets in the inner west to access the Port of Melbourne, exposing residents to harmful diesel exhaust. The impact of this pollution is evident as, in 2019, 1780 Australians died prematurely from PM2.5 vehicle emissions, a figure higher than the annual national road toll.

While newer diesel trucks emit significantly fewer particles than older models, the challenge remains to remove the older trucks from the roads. Electric vehicle conversions have been explored, but the high costs and uncertainty about the old trucks' fate have hindered progress. Additionally, the government's Clean Air Strategy has committed funds to identify and implement solutions to particulate pollution, but it remains to be seen how effective these measures will be in improving Western Sydney's air quality.

In conclusion, Western Sydney's high pollution levels are largely attributed to diesel truck emissions, which have severe health consequences for residents. While efforts are being made to mitigate this issue, such as through the adoption of electric trucks and government initiatives, more decisive action may be required to ensure the air quality in Western Sydney improves and the health of its residents is protected.

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