Air quality fact sheet
Department of the Environment and Heritage, 2005
'Air toxics' are a diverse range of air pollutants that are usually present in ambient1 air in relatively low concentrations but have characteristics such as toxicity or persistence that make them a hazard to human, plant or animal health. These pollutants include volatile and semi-volatile organic compounds, heavy metals and others. Air toxics are sometimes referred to as 'hazardous air pollutants' to distinguish them from the 'common' or 'criteria'2 air pollutants: carbon monoxide, lead, nitrogen dioxide, ozone, particles and sulfur dioxide. (See fact sheet on National Standards for Criteria Air Pollutants in Australia)
Sources of air toxics include: motor vehicle emissions; the products of burning fuels, including woodsmoke; industrial emissions; and materials such as paints and adhesives in new buildings. Air toxics can be a significant air pollution problem in their own right. In addition, a group of air toxics known as 'reactive organic compounds' play an important role in the formation of ozone, an air pollutant that is toxic to humans and is present in photochemical smog. (See fact sheet on ozone)
The potential health risks associated with exposure to air toxics are well established and there is a growing recognition of the need to minimise those risks. Occupational and laboratory studies show that exposure to air toxics can lead to an increase in the incidence of cancer, birth defects, genetic damage, central nervous system defects, immunodeficiency, and disorders of the respiratory and nervous systems. These effects are often more pronounced when sensitive members of the community, such as the very young and elderly, are exposed to air toxics.
Although the current state of knowledge regarding the levels of air toxics in Australia is very limited, there is evidence to suggest that levels of some air toxics may be significant in some regions. People living in regions where there is a high level of woodheater usage may be subjected to high concentrations of polycyclic aromatic hydrocarbons, an air toxic known to cause cancer. The levels of benzene near major roads have been shown to be high, particularly when the traffic is congested.
Monitoring for air toxics in Australia has been very limited to date and more information regarding the levels of air toxics in Australia is required to develop a good understanding of the extent of the problem.
In 2004, the National Environment Protection Council made the National Environment Protection Measure for Air Toxics, which addresses five priority air toxics: formaldehyde, toluene, xylene and polycyclic aromatic hydrocarbons (PAHs). The Measure is primarily concerned with the collection of data on the ambient levels of these five air toxics at locations where elevated levels are expected to occur and there is a likelihood that significant population exposure could occur, taking into account the presence of sensitive groups such as the young and the elderly.
The States and Territories carefully choose the sites for monitoring air toxics for the purposes of the Measure. They take account of significant sources of air toxics such as highly trafficked roads, clustered small to medium enterprises, high levels of woodheater use and the presence of multiple sources, including major industry.
States and Territories have a range of programs in place to control emissions of air toxics from industry and to reduce emissions of air toxics from domestic wood heating. National actions to reduce air toxics emissions include the introduction of more stringent fuel quality standards and Australian Design Rules for new motor vehicles, and measures to improve woodheater technology and operation.
A process is currently underway to consider other air toxics for possible future inclusion in the National Environment Protection Measure for Air Toxics.
Related publications are available from the Community Information Unit of the Department of the Environment and Heritage, phone 1800 803 772. These include the State of the Air Report: Community Summary 1991–2001 and Air Quality Fact sheets on:
- National Standards for Criteria Air Pollutants in Australia;
- carbon monoxide, lead, nitrogen dioxide, ozone, particles and sulfur dioxide;
- woodheaters and woodsmoke; and
- smoke from biomass burning
See also our Air quality website.
The complete National Environment Protection Measure for Air Toxics is available at: http://www.ephc.gov.au/taxonomy/term/35
1. In this context, 'ambient' means 'outdoor'.
2. 'Criteria air pollutants' is a term used internationally to describe air pollutants that have been regulated and are used as indicators of air quality.