25.03.2021 - 6 min read

First look: Air Quality & Pollen

Ever wondered what the local air quality is?

Ever wondered what the local air quality is? Do you sometimes feel like you go outside, you take a deep breath and suddenly your lungs self-implode?

Ok, perhaps that’s an exaggeration, but how do you avoid something you can’t see?

The wheezo app allows you to check air quality and pollen forecasts anywhere you go in Australia. The data is so accurate, it can tell you the air quality down to the hour, within a 5m radius. What’s more, we not only provide an Air Quality Index (AQI), but we drill down into specific irritants that may be more likely to lead to a flare-up.

Information on air irritants and pollens are stored with each wheeze recording and available for your viewing pleasure through your online portal or in the history tab on the app, along with temperature, humidity and air pressure.

What pollutants are tracked and how they may affect asthma symptoms?


  • CO: Carbon Monoxide
  • NO2: Nitrogen Dioxide
  • O3: Ozone
  • PM10: Inhalable Particle Matter (<10μm)
  • PM2.5: Fine Particle Matter (<2.5μm)
  • SO2: Sulfur Dioxide


  • Grass
  • Weeds
  • Trees

Why are these air irritants selected?

Ever heard of smoke and fog (aka smog)? If you’ve never heard of it, you’ve at least seen it as the haze that shrouds capital cities and gives dystopian movies the dirty, filthy, dead city vibe.

Smog is a toxic concoction of many dangerous chemicals with some wreaking havoc on your lungs. When oxides (like nitrogen oxides, sulphur oxides, carbon monoxide) and volatile organic compounds (VOCs) come into contact with heat and sunshine they chemically transform into ozone and particle matter.

With the right weather conditions, smog can travel far distances, even crossing political borders and affecting people far away from the smog’s source of origin.

CO: Carbon Monoxide

If you think of the air pollution that cars cause, you’re probably thinking of carbon monoxide. It’s created when fuel sources are burnt, but not all the way. You can’t see it or smell it, but it’s there.

If you breathe it in, carbon monoxide replaces the oxygen that should be flowing through your blood. Even for people without asthma, a build up of carbon monoxide in your bloodstream is bad, and too much can lead to carbon monoxide poisoning.

Note that low levels of carbon monoxide in your blood is normal, and wheezo cannot tell you the level of carbon monoxide inside your house. It’s also unclear whether carbon monoxide has a direct effect on asthma symptoms.

NO2: Nitrogen Dioxide

Nitrogen dioxide comes from burning fuels at high temperatures (think cars, gas-heaters and gas-stoves). When nitrogen dioxide is breathed in, it mixes with the moisture in your lungs to form nitric acid. This is a strong acid, normally used for making chemical explosives, fertiliser and flour bleach.

It’s not hard to see why nitric acid in your lungs is baaaad. It can damage the cells in your lungs and high concentrations of nitric acid can irritate your airways. Exposure to nitrogen dioxide and ozone over long periods of time, can cause asthma, make existing asthma worse and in extreme circumstances cause people with asthma to die. It can also make you more sensitive to triggers and have more frequent asthma attacks.

O3: Ozone

You may have heard of ozone before, like the ozone layer which protects us from harmful UV rays and the ozone hole which humans created because … who doesn’t like destroying the only planet we can live on. Just like a tortured superhero, ozone can be good or BAD.

When it’s in the stratosphere, it sacrificially absorbs the energy from the UV radiation breaking apart … but it’s ok because like any superhero movie, it comes back miraculously healed as if nothing ever happened.

However, ozone on the ground is very BAD. Just like nitrogen dioxide, chemical reactions happen when too much ozone meets the lungs (oxidative stress), damaging your lung cells and making your airways more inflamed, so you’re more sensitive to triggers. Ozone is also usually found in smog and is a warning sign that other dangerous air pollutants are in the area, namely nitrogen dioxide and small particle matter.

(PM10 and PM2.5) Inhalable Particulate Matter (<10μm) and Fine Particulate Matter (<2.5μm)

Particulate Matter is an umbrella term for any small particles that are so light, they are suspended in the air. This can come from bushfires, wood burning heaters, construction, agriculture, pollen, bacteria, or mould. PM10 covers particles that are smaller than 10 microns in diameter and is usually seen as haze. PM2.5 are smaller than 2.5 microns and can’t be seen.

These particles are so small, they can imbed themselves deep into your lungs. Smaller particles like PM2.5 travel even deeper into your lungs, making it difficult to breathe. PM2.5 can even infiltrate your bloodstream and wreak havoc on your organs, particularly your lungs and heart.

How bad are bushfires for asthma patients?
Air pollution caused by bushfire smoke and debris, can continue to trigger asthma attacks even after the fire subsides. Fine smoke particles (PM2.5) are more toxic than other small particles (such as pollen) resulting in more severe asthma flare-ups. Strong winds spread smoke more than 50km, making it difficult to predict who will be affected.

Sulfur Dioxide
Similar to nitrogen dioxide, sulfur dioxide also forms sulphuric acid. It can damage the cells in your lungs, irritate your airways to cause inflammation, and make you more sensitive to triggers.

Grass, trees and weed pollens

People with asthma may be allergic to different types of pollen. These are blown by the wind to be breathed in and cause your airways to be swole, but not in a good way, making it difficult to breathe. Many people are allergic to different types of pollens, so it’s important to track asthma symptoms with pollen counts, to see if there’s a particular pollen you’re allergic to.

What is thunderstorm asthma?

In 2016, many Melburnians were affected by sudden asthma flare-ups caused by thunderstorms. The mixture of wind and high humidity stirred up grass pollens and other small particles which embedded deep within the lungs, causing inflammation and breathing difficulty.

What to do when air irritant and pollen levels are high?

The health advice is, talk to a healthcare professional and ask them to help you put together an Asthma Action Plan. They may also recommend that you avoid going outdoors if these levels are high.