What is dust?
Dust is a common air pollutant generated by many different sources and activities.
Terms explained
Pollutant – a substance that has been introduced to the environment and has undesired or negative effects.
Particles – tiny solid and liquid substances that can float in the air. Many particles are invisible.
Where does dust come from?
The natural erosion of soil, sand and rock is the most common source of dust.
Pollen, microscopic organisms, plant material and dander (dead skin cells shed by animals) are also part of the dust in the environment.
Man-made dust is common in urban areas. It is created by a range of activities from personal hobbies, such as gardening, to large scale industrial activities, such as electricity generation at power stations.
Dust particles
Dust particles vary in size from visible to invisible. The smaller the particle, the longer it stays in the air and the further it can travel.
Large dust particles fall out of the air relatively close to where they are created. These particles form the dust layers you can see on things like furniture and motor vehicles.
Large dust particles tend to be trapped in the nose and mouth when you breathe them in and can be readily breathed out or swallowed harmlessly.
Smaller or fine dust particles are invisible. Fine dust particles are more likely to penetrate deeply into the lungs while ultrafine particles can be absorbed directly into the blood stream.
How does dust affect your health?
The type and size of a dust particle determines how toxic the dust is. However the possible harm the dust may cause to your health is mostly determined by the amount of dust present in the air and how long you have been exposed to it.
Dust particles small enough to be inhaled may cause:
- irritation of the eyes
- coughing
- sneezing
- hayfever
- asthma attacks.
For people with respiratory conditions like asthma, chronic obstructive airways disease (COAD) or emphysema even small increases in dust concentration can make their symptoms worse.
Currently there is no hard evidence that dust causes asthma, however breathing in high concentrations of dust over many years is thought to reduce lung function in the long term and contribute to disorders like chronic bronchitis and heart and lung disorders.
Industrial emissions may occasionally result in excessive dust in nearby communities. These may be harmful to health if poorly controlled.
Who is at risk?
Anyone who is exposed to high levels of dust may be affected – the longer you breathe in the dust, then the greater the chance that it will affect your health.
Breathing low levels of household or urban dust does not cause health problems in most individuals.
In contrast, people with existing respiratory and heart conditions, including smokers, are at greater risk of developing long-term health problems.
Babies, young children and elderly people are also more likely to develop health problems from long term exposure to high levels of dust.
Anyone who regularly experiences shortness of breath or hayfever type symptoms from breathing dust should discuss these symptoms with their doctor.
What can be done?
Australia controls dust levels in the air where people live through a range of measures. Australian air quality standards for dust are more rigorous than those in the USA, UK and Europe.
National standards
The National Environment Protection Measure (NEPM) for Particulate Matter (PM) is the standard for dust concentration in cities and towns.
The Department of Environment Regulation (DER) monitors and enforces this standard. The DER monitors air quality, including dust, across the Perth metropolitan and major rural areas. The DER investigates all incidents where the standards are exceeded.
Industry licences
The DER licences all industry and activities that emit pollutants into the environment. Either the DER or the Environmental Protection Agency (EPA) can impose conditions on a company that restrict the amount of dust particles that their activities can emit into the air. Companies must monitor their emissions and routinely report the information back to DER.
Other measures
Other dust control measures include vegetation buffers (areas of plants and trees) that are often positioned between residential areas and industrial areas and between residential areas and major roads.
These buffers help to dissipate dust and other pollutants and together with air quality standards are highly effective for reducing dust impacts on communities.