Air quality
Key Messages
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Good air quality is important to maintaining environmental health, including human health. Poor air quality can negatively impact people’s health, particularly children, older people, pregnant women and those with pre-existing respiratory conditions, such as asthma. It can also reduce visibility and damage our environment and ecosystems. Ground-level ozone damages agricultural crops, forests and plants, reducing their growth rates. Nitrogen oxides, and sulphur dioxide harm soil, lakes and rivers by making them more acidic. This can cause a loss of animal and plant life. Ammonia and nitrogen oxides also disrupt land and water ecosystems by introducing excessive amounts of nutrient nitrogen — a process known as eutrophication.
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Air quality is a measure of the purity of the atmosphere, in terms of the quantity of solid, liquid or gaseous air pollutants. The impacts of these pollutants tend to be localised near major sources or groups of sources, since pollutants are continually removed from the atmosphere by processes such as gravitational deposition, rainfall, chemical reaction and solution in water bodies.
The effects of air pollutants can include: human health impacts (short and long-term), irritation, nuisance (e.g. soiling of surfaces from deposited dust or increased corrosion rates), aesthetics (light scattering, visual range, haze), and flora and fauna impacts.
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Air quality in Queensland has improved over the last 3 decades and remains relatively good, generally complying with national air quality standards for 5 of the 6 major air pollutants. This quality has been achieved despite the pressures from a growing population, increased vehicle use and industrial growth. Air quality improvements have resulted from Queensland’s regulation of industry, stricter emission standards for motor vehicles and new emission reduction technology.
Most measures of air quality (carbon monoxide, lead, nitrogen dioxide, sulphur dioxide and ozone concentrations) have reduced, with this reduction being particularly significant for carbon monoxide, lead and nitrogen dioxide.
Particle pollution is the most significant air quality issue in Queensland. This is mainly due to more bushfires and hazard-reduction burning because of high vegetation fuel loads following two years of above-average rainfall.
Key Facts
State
- Ozone concentrations
Ozone levels in Townsville and Gladstone have never exceeded the Ambient Air Quality NEPM 8-hour average standard of 0.065ppm. In the past 20 years, there have been eight years in Southeast Queensland and two years in South West Queensland when the 8-hour standard has been exceeded on at least one day.
All exceedances are linked to extra emissions of photochemical smog-forming pollutants from major bushfires.
- Visibility-reducing particles
In the past 20 years, we have seen a downward trend in the number of days with reduced visibility (defined as a visual distance of less than 20 kilometres) throughout Queensland.
In 2000, 2001 and 2009, we had more than ten reduced visibility days in all Queensland regions due to dry conditions and widespread bushfires.
Due to localised bushfires or hazard-reduction burning, Southeast Queensland recorded additional days (+10 within the year) with reduced visibility in 2004, 2012, 2019 and 2023.
- Particulate concentrations
Particle pollution is Queensland’s most significant air quality issue. Since 2009, windblown dust has been responsible for over 70% of all exceedances of the Ambient Air Quality NEPM 24-hour PM10 standard, mainly from wind erosion of bare ground during dry conditions. In 2023, PM10 levels increased in most regions, mainly due to more bushfires and hazard-reduction burning because of high vegetation fuel loads following two years of above-average rainfall.
- Carbon monoxide concentrations
Carbon monoxide levels have declined over the past decade, with levels in the last five years less than 15% of the National Environmental Protection (Ambient Air Quality) Measure air quality standard of 9ppm.
- Lead concentrations
Lead monitoring results from Mount Isa and Townsville show that the rolling 12-month average lead concentrations are below the National Environmental Protection (Ambient Air Quality) Measure annual average air quality standard of 0.50 micrograms per cubic metre.
- Nitrogen dioxide concentrations
Levels of nitrogen dioxide across Queensland are consistently well below the National Environment Protection (Ambient Air Quality) Measure annual average standard of 0.015ppm. Since 2000, the only exceedances of the one-hour average standard of 0.08ppm on one day have been in Southeast Queensland and Gladstone.
- Sulfur dioxide concentrations
Sulfur dioxide levels in all regions, except for South West Queensland and Townsville, have occasionally exceeded the National Environmental Protection (Ambient Air Quality) Measure 24-hour and one-hour average standards of 0.020 parts per million (ppm) and 0.100ppm, respectively, due to industry emissions.
Pressure
- Vehicle kilometres travelled
In Queensland, total motor vehicle travel (by passenger vehicles, light commercial vehicles, trucks, and buses) has fluctuated over the last few decades, stabilising in recent years to around 51 billion kilometers. Reductions in vehicle kilometres travelled during 2018/2019 and 2019/2020 can be attributed mainly to the COVID-19 pandemic travel restrictions and the increased prevalence of remote working. However, the long-term upward trend suggests that emissions will likely continue to rise without significant interventions to improve vehicle technology or travel behaviour.
- Number of registered vehicles
From 2020 to 2024, registered motor vehicles increased by 13%. Cars comprise about 65% of all registered vehicles, followed by light commercial vehicles at 23%. Hybrid and electric vehicles only make up 4% of all registered vehicles. During 2020-2024, the number of all vehicle types increased, with the most significant increase in campervans/motorhomes and motorised wheelchairs. Our growing population drives this continued and sustained growth.
- Vehicle emissions
Emissions from motor vehicles are a function of many factors. The most important factors are total travel, fleet mix, emission control technology and driving behaviour. Greenhouse gas emissions for motor vehicles in Queensland increased by about 20% from 2010 to 2019. Compared to 2010, the total 2019 emissions were less for most air pollutants. This reflects the effectiveness of emission control technologies and fleet turnover.
- Major air pollutants from industry
Across the state, primary metal manufacturing, coal mining and electricity supply are the main sources of industrial air pollutants. The top four industrial pollutants by tonnes/annum are:
- sulfur dioxide
- particulate matter (PM10)
- oxides of nitrogen
- carbon monoxide.