Australia's Air Pollution Crisis: Why It's So Bad

Australia's air quality is generally considered to be good, with the country experiencing low levels of air pollution year-round. However, during extreme events such as bushfires and dust storms, some parts of Australia have temporarily experienced some of the worst air quality in the world. These events can cause short-term spikes in pollution levels, leading to significant health impacts, including respiratory and cardiovascular issues, and even premature deaths. While industrial emissions are typically well-controlled, specific regions continue to face challenges due to emissions from smelting operations and other industrial activities. Additionally, vehicle emissions, road traffic, power generation, and domestic wood heaters also contribute to air pollution in Australia.

Bushfires and dust storms cause short-term extreme pollution spikes

Although Australia's air quality is generally good, it is vulnerable to short-term extreme pollution spikes due to bushfires and dust storms.

Bushfires, especially during the summer months, are a key reason for these pollution spikes. These fires emit smoke and tiny harmful particles into the air, degrading the 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 resulted in 429 premature deaths and over 3000 hospitalisations due to breathing problems or heart issues caused by smoke inhalation. Bushfires can generate high levels of PM2.5, the most hazardous pollutant to human health, which can penetrate deep into the human system and cause a range of health effects, including decreased lung function, increased respiratory symptoms, and a higher risk of cardiovascular disease, lung cancer, and chronic bronchitis or emphysema. Human activities such as deforestation can also severely impact the occurrence and intensity of bushfires.

Dust storms are another significant contributor to short-term extreme pollution spikes in Australia. These storms are most likely to occur during spring when Australia experiences cold fronts, and they can have a significant impact on air quality. For example, Sydney's "Red Dawn" in September 2009 was a particularly dramatic dust storm that reduced visibility to less than 1 km for several hours, causing road closures and disruptions to flights and ferries. Dust storms are more common in regions with low soil moisture and sparse vegetation coverage, and their frequency and intensity may increase with climate change.

While bushfires and dust storms are natural contributors to short-term extreme pollution spikes, human-influenced factors also play a role. Significant human-influenced air pollution sources include combustion in vehicle engines, road traffic, industrial processes, power generation, and domestic wood heaters. Domestic wood heating is a major pressure on air quality during the winter months in Australia, contributing at least 50% of winter ambient particulate matter.

Industrial emissions in Port Pirie and Mount Isa

Australia's air quality is generally considered to be among the cleanest in the world. However, the country is susceptible to short-term extreme pollution spikes caused by natural events such as bushfires and dust storms. Human-influenced sources of air pollution include combustion in vehicle engines, industrial processes, power generation, and domestic wood heaters.

Mount Isa, a mining town in Queensland, is known for its heavy industry. The town's mine stacks, which dominate the skyline, emit sulphur dioxide produced during the copper smelting process. Mount Isa Mines' Air Quality Control Centre has been monitoring sulphur dioxide and metal levels since 1975. The company must adhere to strict regulations set by the Queensland Government Environmental Authority (EA) to manage sulphur dioxide emissions and ensure the air quality in Mount Isa remains safe for residents.

Port Pirie, located in South Australia, is home to one of the world's largest lead smelters, operated by Nyrstar. The smelter has been in operation for over 130 years and is the main employer in the city. Nyrstar holds a licence under the Environment Protection Act 1993 and is subject to regulations to minimise the risk of air emissions and improve environmental outcomes. Despite upgrades to the smelter in recent years, high blood lead levels remain a concern for the local population, especially in young children.

In summary, while Australia generally enjoys relatively clean air quality, industrial emissions in Mount Isa and Port Pirie contribute to localised air pollution. These emissions are closely monitored and regulated to mitigate their impact on the surrounding communities and the environment.

Vehicle emissions

Despite the increasing number of cars on the road, initiatives and technological advancements have led to a reduction in vehicle emissions in cities like Sydney over the past two decades. Newer vehicles produce significantly fewer emissions than older ones due to improved fuel efficiency, better technology, and stricter emission standards. For example, cars built since 2013 emit only 3% of the oxides of nitrogen emitted by vehicles manufactured in 1976. Australia has vehicle emission standards in place, known as Australian Design Rules (ADRs), which set the maximum level of emissions permitted by a vehicle under specified test conditions. These standards aim to regulate air pollutants, improve air quality, and protect human health.

However, Australia's standards for some pollutants, such as sulfur dioxide (SO2), are considered lax compared to other countries. The country has one of the most lenient sulfur standards for petrol, allowing 150 parts per million, much higher than the limits in the EU, Japan, the US, Brazil, and China. Australia's air quality standards, including the National Clean Air Agreement, have set targets that are even better than the World Health Organization's recommendations for PM2.5. Still, stronger measures are needed to reduce vehicle emissions to meet these targets.

Domestic aviation, dominated by passenger transport, accounts for 9% of transport emissions. Aviation activity increased significantly between 2001 and 2011 and is projected to double by 2030. This growth is driven by economic factors and an increasing preference for air travel over road or rail. While public transport, such as trams and trains, can help reduce air pollution in cities, Australia's electricity generation still relies largely on fossil fuels, shifting the pollution to power plants.

To address vehicle emissions and improve air quality, Australia can implement a range of policies and initiatives. These include incentivizing the purchase of low-emission vehicles, improving fuel efficiency standards, and promoting active travel and the use of public transport for short commutes. Upgrading refineries to supply low-sulfur fuel and adopting stricter standards, such as the Euro 6 standard, can also significantly reduce vehicle emissions and improve public health.

Domestic wood heaters

Australia's air quality is generally good, but it is vulnerable to short-term extreme pollution spikes caused by bushfires, dust storms, and other natural and human-made sources. One significant human-influenced source of air pollution in Australia is domestic wood heaters, particularly during the winter months.

Wood heaters are a popular way to heat homes in Australia, with approximately 900,000 dwellings, or about 10% of the population, using wood as their main source of heating in 2014. This number is even higher in regional areas, with 70% of wood heater users located outside capital cities. During the winter, wood heaters can contribute at least 50% of ambient particulate matter, with wood smoke identified as a major source of air pollution.

The smoke from wood heaters contains a range of harmful pollutants, including particulates, nitrogen oxides, carbon monoxide, volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Some of these pollutants, such as particulates and formaldehyde, are carcinogenic and can have serious health impacts, especially for vulnerable groups such as pregnant women, children, older people, and those with respiratory illnesses. Chronic exposure to wood smoke has been linked to an increased risk of heart and lung disease and can aggravate existing conditions such as asthma, chronic bronchitis, or emphysema.

To address the air pollution caused by domestic wood heaters, several strategies have been proposed and implemented. These include encouraging the use of alternative heating methods, such as gas heaters or reverse cycle air conditioners, and providing incentives for switching to electric heaters. For those who continue to use wood heaters, it is recommended to buy heaters that produce the lowest level of emissions and to have them installed by licensed professionals according to local regulations. Education about the concentrations of air pollutants produced by wood heaters can also help to motivate people to change their wood-burning behaviour and reduce emissions.

While these efforts have had some success in reducing the number of indoor wood heaters and improving air quality, it is important to balance these initiatives with the needs of those who rely on wood heaters as a primary source of heating and the potential economic impact on the wood-fire heater industry.

Lead and mercury emissions

Australia's air quality is generally good, but it is vulnerable to short-term extreme pollution spikes caused by natural and human-made sources. Natural sources include bushfires, which can generate high levels of PM2.5, the most hazardous pollutant to human health. Human-made sources include vehicle engines, road traffic, industrial processes, power generation, and domestic wood heaters.

While lead emissions are not mentioned in the sources, mercury emissions are a concern in Australia. Mercury is a toxic heavy metal that concentrates up the food chain. It is released into the atmosphere from industrial areas, agricultural intensification, energy production, urbanisation, and mining. Australia's gold smelting, coal combustion in power plants, and alumina production from bauxite contribute substantially to mercury emissions. Mercury emissions from burning Australian eucalypt forest surface fuels have also been observed.

Waterways in the Southern Hemisphere, including Australia, face increasing mercury contamination. This undermines the use of these waterways as a source of potable water and harms aquatic organisms. Elevated concentrations of mercury in post-industrialization sediments have been found in several Australian aquatic systems.

There is also evidence of a link between anthropogenic mercury emissions and elevated mercury concentrations in remote areas. Mercury deposited in these areas may originate from distant heavily industrialised regions. As a result, mercury is a global issue affecting not only heavily industrialised areas but also remote regions.

To address mercury emissions, Australia has delayed a major upgrade to smelting operations at Port Pirie, which promises to reduce sulfur dioxide emissions. Additionally, efforts are being made to reduce mercury levels in waterways through controlling and reducing mercury sources, increasing regulations, treating wastewater, and stabilising, dredging, or capping contaminated sediments.

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