With many wildfires burning across the world this summer, we look at the effects they have on air quality.
In August, the European Union reported on wildfires burning in Spain, Portugal, France, Greece, Montenegro, and Albania, stating that air quality had been “severely degraded”.
In the UK, 2025 has seen unprecedented numbers of fires and, across the Atlantic, Canada’s wildfire season has been the second worst on record.
Critically, researchers are concerned that more frequent and intense wildfires risk reversing decades of action and improvements in air quality.
How do wildfires affect air quality?
Wildfires are responsible for releasing large mixtures of hazardous pollutants into the air such as black carbon, particulate matter, nitrogen dioxide, and ozone.
A study published in 2021 suggests that a quarter of the United States’ fine particulate matter (PM2.5) pollution is caused by wildfires, increasing to half in some regions. Concerningly, research published last month found that wildfire-related PM2.5 is more dangerous (associated with greater mortality) than PM2.5 from other sources.
When vehicles, plastics, and buildings catch fire in urban areas, smoke can also contain lead. During the January 2025 Los Angeles fires, an estimated 110-fold increase in PM2.5 lead concentrations was recorded, when compared to values in the days beforehand.
Smoke from wildfires can also travel long distances and affect air quality in locations far away from the flames. For example, in May, NASA found that Canada’s wildfires were producing smoke plumes so vast they were visible from deep space and causing hazy skies as far south as Florida.
The longer smoke particles stay in the atmosphere, they undergo chemical changes – or “age”. Results have shown that this can make them four times more toxic.
How is air pollution from fires tracked?
With fires able to reach tens of thousands of hectares in size, satellite observations are essential in monitoring them. The Copernicus Air Monitoring Service (CAMS), part of the EU’s Earth observation programme Copernicus, uses satellite-based sensors to track wildfires. Measurements are used to estimate gas and particulate matter emissions from the fires, as well as model and forecast how and where the pollution will spread.
Air quality monitoring at ground level is also critical in providing near-real-time information for the public on the air that they’re breathing. The Automatic Urban and Rural Network (AURN) is the UK’s largest air quality monitoring network and measures particulate matter, nitrogen dioxide, and ozone – all produced by wildfires. The UK also has a network dedicated to monitoring black carbon. Cura Terrae are official distributors of instruments used in these networks, such as the Palas Fidas® 200 particulate matter analyser and the Aerosol Magee Scientific Aethalometer® AE-33 black carbon monitor.
Community air monitoring initiatives are also becoming more common, empowering residents with data hyper-local to their area. The Imperial County Community Air Monitoring Project was the first large-scale community air monitoring network of its kind. Imperial County, California, has been affected by fires in Los Angeles and has the highest rate of hospitalisations for asthma among school-age children in the state. In collaboration with public bodies, residents added forty particulate matter monitors to a network that previously contained only five. Get in touch with our team to discuss sensors for community-level monitoring, such as the bettair® node.
These data enable individuals – when there is no direct risk from the fire itself – to protect themselves from pollution by limiting outdoor activities and exercise; keeping windows closed; and reducing sources of indoor pollution such as smoking, stove use, aerosols, and cooking. This advice is particularly important for people who are most at risk: children, the elderly, individuals with pre-existing cardiovascular or respiratory conditions, and pregnant women.
Fires are changing the story of air quality
According to US atmospheric scientist Tracey Holloway, “Fires are really changing the story” of air quality. Wildfires are unpredictable, and often occur in areas away from those traditionally covered by monitoring networks, such as transport and industrial hubs. Cura Terrae Air has four decades of experience in the air monitoring industry. We can help you navigate today’s air quality challenges.
Get in touch with our expert team.
