- During bushfires, like other forms of air pollution, fine particles known as PM2.5 are a key concern for public health.
- Health effects of short-term exposure to bushfire smoke include irritation of the nose, throat and eyes, coughing, sneezing and congestion.
- During short bushfire smoke events, you should stay indoors and avoid physical exercise outdoors where possible. You should also keep your windows and doors shut and ventilate your house once the bushfire smoke clears.
- There is limited evidence on the long-term health effects of prolonged exposure to bushfire smoke. However, evidence shows the risk of illness declines when air pollution levels fall, even after very long periods of exposure.
- Staying indoors may not be practical over prolonged periods and some homes, especially older ones, may more easily allow bushfire smoke in. In such circumstances, people may be able to take advantage of alternative well-sealed and air conditioned indoor locations to provide respite from bushfire smoke pollution (e.g. libraries, shopping centres, cinemas).
- It is important to be aware of the conditions outside and monitor the air quality conditions to determine the best times for outdoor exercise and ventilating your home.
- Exercising outdoors, including cycling or walking to school or work when bushfire smoke levels are low, if possible, will help to maintain good physical activity levels without substantially increasing exposure to bushfire smoke.
Smoke from bushfires is made up of various gases, water vapour and coarse and fine particles. Landscape fire smoke is produced by the incomplete combustion of organic material, including plants and soils. The gases in bushfire smoke include carbon monoxide, carbon dioxide, nitrogen oxides and volatile organic compounds.
Fine particles, also called suspended particulate matter (PM), are 2.5 microns or less in width or less than one thirtieth the width of a strand of human hair and are therefore known as PM2.5. They reduce visibility and, when inhaled, can penetrate deep into a person’s lungs and can be absorbed into the bloodstream. Conversely the coarser particles that are also a component of bushfire smoke, known as PM10 particles, cannot be absorbed into the bloodstream, however they can cause irritation to the lungs and discomfort for the eyes and throat.
Those most at risk of significant health effects of exposure to bushfire smoke include:
- people with existing heart or lung conditions, including angina, ischaemic heart disease, asthma and chronic obstructive pulmonary disease (bronchitis and emphysema)
- people over 65 years of age as they are more likely to have heart or lung disease
- children 14 years and younger
- pregnant women
- people with diabetes
What does short-term exposure and prolonged exposure mean?
For the purpose of this guidance material, short-term exposure refers to a person being exposed to bushfire smoke for less than 24 hours.
Prolonged exposure refers to either sustained exposure to bushfire smoke for greater than 24 hours or repeated short-term exposure with little time in between.
What are the health effects of short-term exposure to bushfire smoke?
Common symptoms of short-term exposure to bushfire smoke can include:
- eye, nose, mouth and throat irritation
- coughing including producing sputum
What are the health effects of prolonged exposure to bushfire smoke?
Exposure to air pollution over days or weeks increases the risk of illness. Evidence shows the risk of illness declines when air pollution levels fall, even after very long periods of exposure.
However, the potential effects on someone’s health long after a period of prolonged exposure to bushfire smoke remain uncertain. Research is ongoing to better characterise the longer term health effects particularly across groups at higher risk, such as those with chronic conditions, very young children, pregnant women and their babies.
I’m experiencing health problems due to the bushfire smoke – what should I do?
If you are experiencing any health issues, you should seek medical attention.
Some individuals with pre-existing conditions or sensitivity to bushfire smoke may experience exacerbation of their underlying condition during prolonged exposure to elevated PM2.5 levels.
People in this circumstance should speak to their doctor about whether this will impact on the existing management of their underlying condition. This should be in conjunction with other measures to reduce exposure.
What can I do to reduce my risk of exposure during short-term bushfire smoke events?
If you see or smell bushfire smoke outside, you should stay inside when safe to do so. Remember to:
- keep your windows and doors shut
- avoid use of evaporative cooling as it draws external air in
- where possible use an air conditioner with a recycled air setting (seek information from your manufacturer)
- take a break from the smoky conditions – for example, visit a friend or go to a large air-conditioned location such as a cinema or shopping centre
- ventilate your house when the bushfire smoke clears
- look out for children, older people, and others at risk
- keep pets inside with clean water and food and keep pets’ bedding inside if possible
What can I do to minimise my exposure during prolonged bushfire smoke events?
Staying indoors may also not be practical over longer periods especially in older homes that more easily allow bushfire smoke in. During longer periods of poor air quality, if safe to do so, people can visit alternate locations which provide a well-sealed and air conditioned indoor environment to provide respite from bushfire smoke pollution (e.g. libraries, shopping centres, cinemas).
Homes should also be ventilated during periods of cleaner outdoor air quality to avoid build-up of indoor pollution. Avoid sources of indoor air pollution such as the use of candles and cigarettes.
How do I keep active during prolonged bushfire smoke events?
Avoiding physical exercise outdoors may not be practical over prolonged periods. In these circumstances it is important to monitor the air quality conditions which will allow you to determine the best times to go outside. Exercising outdoors, including cycling or walking to school or work within this time-window, if possible, would help maintain good physical activity levels without substantially increasing exposure to bushfire smoke.
Do air purifiers help to reduce PM2.5 particles inside my home?
Air purifiers with a high efficiency particle air (HEPA) filter are able to reduce the number of fine particles indoors. To work well, the air purifier must be matched to the size of the room it is in and the room must be well sealed.
Humidifiers, negative ion generators and odour absorbers do not remove fine particles in bushfire smoke.
Is there an increased risk for pregnant women during prolonged bushfire smoke events?
The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) advise that prolonged exposure to bushfire smoke and poor air quality can have adverse pregnancy outcomes. Pregnant women should take advice from their treating health practitioner.
Should I purchase a P2 mask?
P2 masks are not recommended for general community use. The use of P2 masks should be limited to:
- vulnerable people including those with significant health issues
- people whose only option is to work outside
- people returning to their properties in burned areas
More information is available on this fact sheet.
Where can I get information on the air quality in my area?
People can access the below links for information and regular updates on air quality, including the PM2.5 levels, for each state and territory. These websites will give you advice on the best way to use the available information for your location.
- Australian Capital Territory Air Quality Index
- New South Wales Current and Forecast Air Quality
- Northern Territory Air Quality Network
- Queensland Air Quality Monitoring
- South Australia Air Quality Monitoring
- Tasmania Real Time Air Quality
- Victoria AirWatch
- Western Australia Air Quality Index