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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.