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How Do Heat Waves Affect Air Pollution?

Updated: Aug 8, 2022

From burnt skin to dehydration, we all know the effects that the sun or hotter temperatures can have on our health, so we slap on the sun screen and avoid going out for too long. But many might not know that the heat can also make air pollution worse, which has a knock-on effect for our health in other ways.

With the world predicted to experience longer, hotter heat waves for many years to come, it’s a good idea to understand how it affects pollution and what we can do to prevent or avoid it.

Here are some ways heat waves affect air pollution.

Ground Level O-Zone Pollution Increases

When it’s hot and the sun is shining, chemical reactions between air pollutants such as nitrogen oxides, which are produced by engines, can be triggered to form ozone. Higher temperatures and lots of intense sunlight cause even more ozone to form.

This can be especially worse in cities, where there is high atmospheric pressure, which causes the pollutants to become trapped. This creates a higher concentration of pollutants that people breathe in and out.

Air Stops Moving

When the air heats up, it becomes more stagnated, meaning more pollutants, like nitrogen oxide and particulate matter, get stuck at ground level.

With little to no wind and minimal precipitation, pollutants build up right above ground level and stay there. The longer they linger, the higher the likelihood of these dangerous pollutants entering our lungs or, even worse, our blood stream.

Wildfires start and smoke pollution spreads

Wildfires can be caused by a number of things – glass bottles on dry grass, cigarette butts and campfires. And while we associate them with the hotter countries of the world, during heat waves, we see them crop up almost everywhere, leading whole villages to burn and fire-fighting teams unprepared to tackle such large flames.

Due to the swathes of smoke which can drift for miles and the spikes in fine particle air pollution and carbon monoxide, wildfires are seen as a huge risk to public health, not to mention the safety of people who have to quickly flee their own home when one approaches. When a wildfire happens, the air pollution levels can rise in towns and cities up to 100 miles away.

Wild fires also release a huge quantity of CO2 which is stored in the vegetation, especially in the trees. Over time, this release of CO2 increases the global risk of other heat waves.

Barbecues Produce Harmful Pollutants

Barbecues are synonymous with warm weather. But depending on which one you pick, you could be polluting the air even more.

Barbecue fuel and coal-based barbecues (especially disposable ones) release dangerous particulate matter and gasses, such as VOCS and PAH, into the air.

Gas barbecues or electric grills are seen as the cleaner alternative – and they’re easier to light and control – so there’s a smaller risk of one turning into a wildfire.

Why Is This A Problem?

According to research, heat waves can increase mortality. A study found that the number of daily deaths during a heatwave was 54% higher on high ozone days compared to low. It was also found that heat waves caused greater respiratory mortality.

Different types of air pollution, which are often greater during heat waves, can cause a number of serious health issues, too.

For instance, ozone and PM 10 can cause breathing problems like coughing and wheezing, exacerbate lung diseases such as asthma and are known to contribute to cardiovascular problems and premature death, but are most harmful to those with preexisting conditions.

How Can You Protect Yourself From Air Pollution?

Apart from the obvious ‘don’t play with fire when it’s hot’, there are some other nifty solutions when heat waves strike:

  1. Download the Pure Air Zone App – not only can you check the current air quality in your area, but you can also vote for cleaner air in the places that you like or visit regularly.

  2. Buy a U-Mask – for the times when you need to step outside, it helps to have extra protection. The U-Mask Model 3 includes an inner filter that offers specific protection against the smallest fine particles and dust with no compromise on comfort or design.

  3. Stay away from busier roads and main streets, especially if you’re exercising. Use back streets and avoid going out at the hottest time of the day.


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