How bushfire smoke affects your health

During bushfire season, Sydneysiders can see the air quality reach hazardous levels in parts of the city due to the smoke. A/Prof Janet Rimmer, from our Thoracic Medicine department, tells us more about the impact the smoke can have on your health, and the precautions you should take.

Can you start by telling us how the bushfire smoke affects our health?

Bushfire smoke contains fine particles which can be inhaled deep into the lungs, so when the level of smoke reaches a certain intensity, there are health-related issues for everybody. The best way to keep informed about it is by checking the air quality index, which gives an indication of what the air quality is like on any given day. Usually Sydney's air quality is good, but when the bushfire smoke reaches the city, it can plummet to hazardous levels, just like this week - a few days ago Sydney was among the worst cities in the world for air quality. When it reaches this level, it can cause symptoms in everyone, but more particularly in individuals with an underlying predisposition to having a lung disease.

What kind of symptoms do people suffer from?

For people without any respiratory condition, it would be irritation: their eyes can become itchy, they can have discomfort in their nose, and get a burning sensation at the back of their throat, or an irritation in their trachea. 

The smoke will cause more serious symptoms in susceptible people, who suffer from asthma, chronic bronchitis, emphysema, or chronic obstructive pulmonary disease (COPD). For them, the bushfire smoke can be a trigger factor and has the potential to make their symptoms worse, namely shortness of breath, coughing and wheezing.

What precautions should people take?

The first thing people need to do is to check the air quality index. If it’s poor, people with a respiratory condition know they can get worse by going outside – so based on the index, they should try to avoid going outside if they can, and plan their day accordingly. If they are driving, they need to re-circulate the air in the car rather than bringing air in from outside.  If they're in close proximity to a bushfire area, they may need to wear a mask called a P2 mask. If they're symptomatic, they need to use their treatment management plan: everybody with respiratory conditions should have this type of plan available, so they know what to do when they have symptoms. That usually means increasing their medication. 

One other recommendation is to avoid physical exercise outdoors - that would apply to everyone. When you exercise, you breathe in more air, and you don't really want to do that when it's poor quality. 

Can there be long-term consequences?

Probably not with a single exposure, but if repetitively exposed to high levels of poor air quality, it can have a long-term impact on your health.

One pollution indicator often used in air quality reports is PM 2.5, which refers to particulate matter: fine particles in the air that are 2.5 micrometres wide or less. Because they’re so tiny, you can inhale these particles into your lungs. If you live in a very polluted area and inhale these particles over long term, you have increased risk of respiratory and cardio-vascular diseases.

Credit: photo by Min An