Bushfire smoke can pose a health risk to recreational and high performance athletes. The health impact of bushfire smoke can vary based on an individual’s current health status and previous medical conditions. Current public health advice is aimed at high-risk groups, including people over 65, children 14 years and younger, pregnant women and those with existing heart or lung conditions. However, athletes involved in high performance sport can also be at increased risk while performing high intensity prolonged exercise outdoors and additional caution should be taken.

When pollution exposure is at low levels, the respiratory tract’s usual defence mechanisms trap, transport and clear pollutants effectively. With elevated exposure, short-term accumulation can occur resulting in inflammation and this can exacerbate a number of health conditions with asthma being the most common in athletes.

During exercise, respiratory rate and volume increases, this in turn increases the total airway exposure to pollutants. In high performance athletes, moderate exercise can increase the total amount of air passing through the airway by more than 10 times and vigorous exercise by more the 20 times, compared to resting values. Even at moderately reduced air quality, this can represent a significant increase in pollutant exposure during a one-hour, high intensity training session.

Air Quality Index (AQI) or PM2.5 in µg/m³?

Most State and Territory government websites (except for Tasmania and Victoria) present air quality information as the ‘Air Quality Index’ or AQI calculated from a 24-hour average. The AQI is calculated for a number of pollutants (including fine and coarse particulate matter, carbon monoxide and ozone). It was designed as a way to standardise information across these different types of air pollution. This means that the AQI number is not a raw measurement (e.g. micrograms of pollutant per metre cubed of air), but a scale based on how much the reading is above (or below) the air quality standard. Some States and Territories provide the AQI separately for different pollutants, others provide only a composite AQI that is based on the pollutant that is the worst. For more details on how the AQI is calculated in your area, please see your local air quality agency’s website.

PM2.5 are very small particles usually found in smoke. They have a diameter of 2.5 micrometres (0.0025 mm) or smaller. PM2.5 particles are a common air pollutant. Breathing in PM2.5 particles can have negative effects on your health. PM2.5 particles are small enough for you to breathe in deeply into your lungs. Sometimes particles can enter your bloodstream.

PM2.5 is measured at all air quality measuring sites in Australia. The other pollutants that make up the AQI are not measured everywhere in Australia. This means that PM2.5 has the relevance for providing a standardised guidelines for all of Australia. PM2.5 is also by far the most important air pollutant in smoky conditions.

Smoke concentrations in the atmosphere can vary markedly within a short distance (e.g. 2 km) and can change rapidly over time. 24 hour rolling average of PM2.5 is useful for knowing the average PM2.5 levels in the air over the past 24 hours, at a point in time. The 24 hour rolling average does not, however, necessarily give an accurate understanding of real-time PM2.5 concentration.  For individuals wishing to make decisions about whether it is safe to exercise now, or over the next couple of hours, having real-time or hourly averages of PM2.5 is important.

For these reasons, the AIS guidelines are based on real time or hourly PM2.5 readings.

How do I find out the PM2.5 levels at my location?

There are three ways to get information on PM2.5 concentration levels (measured in µg/m³):

  1. State and Territory air quality monitoring websites (hourly measures of PM2.5 concentration)
  2. The AirRater App (or other similar App providing real time PM2.5 in µg/m³)
  3. A handheld portable device that measures PM2.5 in real time

State and Territory air quality monitoring websites:

The following links will be useful in helping you find the relevant website in your State:

Unfortunately, different States and Territories have slightly different systems for measuring air pollution, different means of presenting information and varying categories and systems for different levels of pollution (good, fair, moderate etc.).

The AirRater App

The AirRater App was originally funded by the Australian Government and is currently funded by the Menzies Institute for Medical Research. AirRater draws its air pollution information from State and Territory air quality monitoring networks. It presents information on PM2.5 concentration in mcg/m³ and applies the same system of measurement for all locations in Australia. To find out more about how AirRater sources and presents its data visit: https://airrater.org/air-quality-explainer/.

Handheld devices for measurement PM2.5

There are range of commercial handheld measurement devices available for measuring PM2.5 concentration in the atmosphere. It is important that the device used is designed for measurement of outdoor rather than indoor concentrations of PM2.5. Teams and sporting clubs may wish to utilise one of these devices for providing real-time measures of PM2.5 concentration at their specific location at the time that they wish to exercise. That value can then be used to advise athletes and officials about appropriate exercise activity.

Exercise-specific categories for smoke affected environments

Table 1 below has drawn on information from several of the Australian State and Territory websites and modified information specifically for application to decisions around physical exercise in smoke affected environments. There are many factors that contribute to readings found on State and Territory websites, air quality apps and handheld devices. The numbers on the table below are a guide and should not be taken as absolutes. There is a need to use common sense in assessing the environment and utilising other factors such as visibility in making a decision about whether or not exercise is appropriate.

Table 1. Guidelines for exercise in smoke affected environments

Exercise Category

General Recommendations

Exercise-specific Recommendations

PM2.5 µg/m³

Good
to exercise

  • It is a good day to be outside.
  • All forms of exercise are encouraged.

<25

Moderate

Caution for those who are sensitive to air pollution

  • The air is probably smoky.
  • Sensitive groups may experience symptoms like coughing or shortness of breath.
  • If you are sensitive to air pollution, spend less time outside in the smoke or dust and follow your treatment plan.
  • If you are worried about your symptoms, seek medical advice.
  • If you are sensitive to air pollution, you may need to reduce prolonged high intensity endurance exercise (e.g. rowing, cycling, long-distance running).
  • Most individuals will tolerate exercise as normal, without symptoms.

25-50

Poor conditions for exercise

  • The air is probably very smoky.
  • Sensitive groups and/or others may experience symptoms like coughing or shortness of breath.
  • If you are sensitive to air pollution, spend less time outside in the smoke or dust and follow your treatment plan.
  • If you are worried about your symptoms, seek medical advice.
  • Seek urgent medical help if anyone has trouble breathing or tightness in the chest. Call 000 for an ambulance.
  • Consider reducing prolonged high intensity endurance activities (e.g. rowing, cycling, long-distance running).
  • If you are sensitive to air pollution, avoid prolonged high intensity endurance exercise (e.g. rowing, cycling, long-distance running) or move it indoors.
  • Intermittent exercise (e.g. tennis, netball, beach volleyball, cricket) and power activities (e.g. sprint training, javelin training, jump training, rugby skills training) may still be well-tolerated but athletes should be alert to symptoms.
  • Increase rest-to-activity ratio for intermittent exercise.

51-100

Very poor conditions for exercise

  • The air is probably very smoky.
  • Sensitive groups and/or others may experience symptoms like coughing or shortness of breath.
  • If you are sensitive to air pollution, spend less time outside in the smoke or dust and follow your treatment plan.
  • If you are worried about your symptoms, seek medical advice.
  • Seek urgent medical help if anyone has trouble breathing or tightness in the chest. Call 000 for an ambulance.
  • High intensity endurance activities (e.g. rowing, cycling, long-distance running) should be avoided or moved indoors.
  • Intermittent exercise (e.g. tennis, netball, beach volleyball, cricket) and power activities (e.g. sprint training, javelin training, jump training, rugby skills training) may still be well-tolerated but athletes should be alert to symptoms.
  • Increase rest-to-activity ratio for intermittent exercise.
  • Any individual may be affected by exercising in smoky air at these levels. If symptoms develop, cease exercise and move indoors.

101-150

Likely to be hazardous to exercise outdoors

  • The air is probably extremely smoky. Everyone will be at risk of experiencing symptoms like coughing or shortness of breath.
  • Listen to your local emergency radio station or visit your State Emergency Agency for advice.
  • Stay indoors away from smoke and dust.
  • If you are sensitive to air pollution, follow your treatment plan. Close your windows and doors to keep smoke and dust out of your home.
  • If you think the air in your home is uncomfortable, consider going to an air-conditioned building like a library or shopping centre for a break if it’s safe to do so.
  • If you are worried about your symptoms, seek medical advice.
  • Seek urgent medical help if anyone has trouble breathing or tightness in the chest. Call 000 for an ambulance.
  • Most individuals should avoid physical activity outdoors.
  • Where there is an intention to play organised high level sport and there are medical staff on site to advise, these levels of pollution should trigger a discussion between medical staff and officials about the advisability or otherwise of proceeding with the event.
>150

Activity levels based on visibility, air health category and smoke sensitivity

The above table provides exercise guidelines but individuals should also remember that there is high variability in PM2.5 across relatively short distances and quite rapid changes across time. Those wishing to exercise should also take note of the visibility and keep in mind their own individual experience of sensitivity to smoke pollution. The following visibility guidelines should be considered in conjunction with the information from the above table. These visibility guidelines are based on those of the Victorian Environment Protection Authority

Table 2. Activity levels based on visibility

Visible landmark

Air health category 

Activity levels – people sensitive to smoke

Activity levels – everyone else 

About 20 km

Good

It's a good day to be outside.

It's a good day to be outside.

About 10 km

Moderate

It's okay to be outside but watch for changes in air quality around you.

It's okay to be outside but watch for changes in air quality around you.

About 5 km

Poor

Reduce prolonged or heavy physical activity.

Normal activity, but be alert to changes in air quality

About 1.5 km

Very poor

Avoid physical activity outdoors.

Reduce prolonged or heavy physical activity.

Less than 1.5 km

Hazardous

If you can, stay indoors and keep physical activity levels as low as possible.

Avoid all physical activity outdoors.

Additional Information

  • Air quality information on State and Territory government websites is generally updated hourly; therefore, there can be a lag between official measurements and what is occurring in real time. This can cause limitations when it comes to determining the air quality in your local environment. If smoke is affecting usual visibility within your area, it is likely that the air quality will fall into a higher risk category.
  • Consecutive days of exposure to polluted air can have a cumulative effect, lowering an athlete’s threshold for symptoms. This should be considered if your region has been exposed to increased smoke for several days in succession.
  • Increases in exercise intensity and duration result in increased airway exposure to polluted air. The AIS recommends modifying training or training locations based on the table above.
  • All athletes who suffer from asthma should have an updated asthma management plan and consult their doctor prior to exercising in smoke-affected environments.
  • Recent respiratory infection increases the risk for development of smoke-related symptoms, even in non-asthmatics.