READ

Particle 101: Epidemic thunderstorm asthma

What's the deal with thunderstorms and asthma?
Michelle Aitken
Michelle Aitken
Content Creator
Particle 101: Epidemic thunderstorm asthma
Image credit: Gavin Poh via Unsplash

One stormy November night in 2016, a horror story unfolded across Melbourne.

Amidst strong winds and hail, thousands of people simultaneously started struggling to breathe.

There was a 681% increase in asthma-related hospital admissions, and 10 people died. Some of them had never experienced asthma symptoms prior to the storm.

This event is the most severe recorded case of a phenomenon known as epidemic thunderstorm asthma.

But how does one thunderstorm trigger thousands of asthma attacks? And how are we monitoring the risk of future events?

IT’S NOT EASY BEING WHEEZY

To understand epidemic thunderstorm asthma, we need to understand asthma itself.

View Larger

A common type of asthma inhaler

Image credit: Getty Images
A common type of asthma inhaler

Asthma is a chronic non-communicable disease affecting around 1 in 9 Australians.

People with asthma experience coughing, wheezing and shortness of breath due to inflammation and narrowing of small airways in their lungs.

Asthma symptoms can be worsened by a variety of triggers, including illness, allergens like pollen and fur and changes in the weather.

A sudden onset of symptoms is called an asthma attack, and it can be life threatening.

Fortunately, for people with access to healthcare, asthma is easily treatable. Currently, most asthma medications are delivered directly to the lungs through an inhaler.

However, if you’ve never experienced asthma before, it’s unlikely that you’ll have the correct medication on hand. And that’s what makes epidemic thunderstorm asthma events so dangerous.

A PERFECT STORM

The cause of epidemic thunderstorm asthma is not fully understood. And it seems that it can’t happen everywhere.

So far, within Australia, Victoria and New South Wales are considered to be at risk of experiencing epidemic thunderstorm asthma. However, there’s no indication that it could happen in Western Australia.

When the event does happen, from what research has found so far, it seems to require an unlucky combination of environmental factors.

First, the level of airborne grass pollen has to be high. This is usually when grasses are flowering. In Melbourne, this is from November to late December each year. During this period, people with hay fever will already be experiencing discomfort.

Second, there has to be a storm. The rain or humidity from a thunderstorm can cause individual granules of pollen to burst apart, flinging hundreds to thousands of minuscule allergy-causing particles into the air. These tiny pieces can then be picked up by strong winds and dispersed over large areas.

View Larger

Ryegrass pollen can be responsible for seasonal allergies

Image credit: Pixabay
Ryegrass pollen can be responsible for seasonal allergies
View Larger

A pollen granule bursting, releasing smaller particles

Image credit: Deakin University
A pollen granule bursting, releasing smaller particles

Usually, our nose and upper airways can filter out larger pollen particles. But these smaller particles bypass our defences and travel deep into the lungs, causing an allergic response and potentially an asthma attack.

And that’s essentially how the rare epidemic thunderstorm asthma occurs.

SCIENCE IN A- AA- ACTION

After the 2016 thunderstorm asthma incident, the Victorian Government launched a strategy to be better prepared for next time. This included spreading awareness, reviewing the emergency response system and building a world-class forecasting system.

The system was developed in collaboration with organisations including the CSIRO, Bureau of Meteorology (BOM), University of Melbourne and Deakin University. It uses statistical computer modelling to predict the risk of thunderstorm asthma 3 days into the future.

To do this, the system needs to calculate the likelihood of grass pollen and the weather creating a deadly combination.

It’s a complex model requiring data from a number of sources like pollen-monitoring stations, satellite observations of grassy areas and weather data from BOM.

Through proper analysis, all of this data allows us to forecast the likelihood of a thunderstorm asthma incident occurring. This helps vulnerable people make decisions like staying indoors or carrying an inhaler.

CHANGING CONDITIONS AHEAD

The Victorian forecasting system has been active since 2017, providing health information for Melbourne and surrounding areas.

However, climate change is contributing to shifting distributions of grasses and increasing the amount of grass pollen in the air. This means thunderstorm asthma events could start occurring in new areas of southeastern Australia, with at-risk areas expanding outwards from the locations of past events.

As environmental conditions change, epidemic thunderstorm asthma events may become common. And as a key component of our emergency public health response, developments in our cutting-edge forecasting system will become increasingly important in keeping us safe.

Michelle Aitken
About the author
Michelle Aitken
Michelle is interested in the relationships between science, culture, and policy. She has a background in performing arts and hospitality, and is a MEAA member.
View articles
Michelle is interested in the relationships between science, culture, and policy. She has a background in performing arts and hospitality, and is a MEAA member.
View articles

NEXT ARTICLE

We've got chemistry, let's take it to the next level!

Get the latest WA science news delivered to your inbox, every fortnight.

This field is for validation purposes and should be left unchanged.

Republish

Creative Commons Logo

Republishing our content

We want our stories to be shared and seen by as many people as possible.

Therefore, unless it says otherwise, copyright on the stories on Particle belongs to Scitech and they are published under a Creative Commons Attribution-NoDerivatives 4.0 International License.

This allows you to republish our articles online or in print for free. You just need to credit us and link to us, and you can’t edit our material or sell it separately.

Using the ‘republish’ button on our website is the easiest way to meet our guidelines.

Guidelines

You cannot edit the article.

When republishing, you have to credit our authors, ideally in the byline. You have to credit Particle with a link back to the original publication on Particle.

If you’re republishing online, you must use our pageview counter, link to us and include links from our story. Our page view counter is a small pixel-ping (invisible to the eye) that allows us to know when our content is republished. It’s a condition of our guidelines that you include our counter. If you use the ‘republish’ then you’ll capture our page counter.

If you’re republishing in print, please email us to let us so we know about it (we get very proud to see our work republished) and you must include the Particle logo next to the credits. Download logo here.

If you wish to republish all our stories, please contact us directly to discuss this opportunity.

Images

Most of the images used on Particle are copyright of the photographer who made them.

It is your responsibility to confirm that you’re licensed to republish images in our articles.

Video

All Particle videos can be accessed through YouTube under the Standard YouTube Licence.

The Standard YouTube licence

  1. This licence is ‘All Rights Reserved’, granting provisions for YouTube to display the content, and YouTube’s visitors to stream the content. This means that the content may be streamed from YouTube but specifically forbids downloading, adaptation, and redistribution, except where otherwise licensed. When uploading your content to YouTube it will automatically use the Standard YouTube licence. You can check this by clicking on Advanced Settings and looking at the dropdown box ‘License and rights ownership’.
  2. When a user is uploading a video he has license options that he can choose from. The first option is “standard YouTube License” which means that you grant the broadcasting rights to YouTube. This essentially means that your video can only be accessed from YouTube for watching purpose and cannot be reproduced or distributed in any other form without your consent.

Contact

For more information about using our content, email us: particle@scitech.org.au

Copy this HTML into your CMS
Press Ctrl+C to copy