The mega-wildfires that, due to climate change, are increasing in frequency and intensity across the world are responsible for a catastrophic impact in health terms. According to the latest Air Quality and Climate Bulletin from the World Meteorological Organization (WMO) and Global Atmosphere Watch, the smoke generated by wildfires was responsible for an average of 100,000 additional deaths per year globally during the period between 2010 and 2018.

A toxic cocktail in mega-wildfire smoke

Carbon monoxide, hydrogen cyanide, nitrogen oxides: what is released by flames is a toxic cocktail that in many cases can prove lethal. Added to this are fine particles, capable of penetrating the lungs and, in the case of the smallest particles, also the bloodstream, thereby contaminating other organs as well.

Not to mention other carcinogenic substances that may be present in the smoke (since what burns is not necessarily just tree trunks and vegetation): from polycyclic aromatic hydrocarbons to dioxins, from heavy metals to pesticides. "The severe health repercussions from wildfire smoke are explained precisely by the unique chemical composition, high toxicity and great capacity to cause oxidative stress in the body, compared to other sources of air pollution," the report states.

"Mortality from fine particles is likely underestimated"

The analysis also stops at eight years ago: it is likely that the data has since worsened further, given the pressure exerted by climate change, with the multiplication of extreme heat waves and droughts. A situation that particularly affects the most vulnerable people: the elderly, newborns and especially people already suffering from respiratory or cardiac conditions.

Current air quality risk assessments often fail to adequately capture the greater toxicity of wildfire smoke. "An epidemiological study – the report reads – has shown that conventional risk models based on total PM2.5 concentrations (the most dangerous fine particles, ed.) could underestimate mortality attributable to wildfires by up to 93 per cent, highlighting the need to account for the greater toxicity of fire-derived particles in such models."

More than 600,000 hectares consumed in Europe in the first eight months of 2026

At a geographical level, over the period under analysis, the WMO recorded an increase in mortality particularly in sub-Saharan Africa and Eastern Europe. In the two regions, the increase in deaths linked to smoke exposure was respectively 28 and 24 per cent, as also indicated by a study published in Nature in 2025 and cited by the UN body itself. Meanwhile, as recently highlighted by the World Health Organization (WHO), in just the first eight months of the current year, more than 600,000 hectares have been consumed by wildfires in the European Union. A figure markedly higher than the average over the last twenty years, which does not exceed 280,000 hectares.

"Extreme drought conditions are exposing numerous European regions, including the British Isles and southern Scandinavia, to increased wildfire risk," the WHO observes. According to the organisation, "in the near future the danger could be further heightened by the progression of El Niño, a cyclical natural climate phenomenon, which could amplify the impact on temperatures and precipitation." It is moreover well known that "most fires in Europe are caused, intentionally or otherwise, by human activity. But their intensity and capacity to spread is strongly influenced by global warming."

The area affected by wildfires could triple by 2100 in Europe

Higher temperatures and stagnant air, the WMO report further warns, also increase concentrations of ozone, another harmful agent for health. "Tropospheric ozone pollution – the document reads – affects human health, agriculture and ecosystems and represents a growing problem. Rising temperatures, stagnant atmospheric conditions and intense solar radiation favour its formation, as demonstrated by recent studies conducted during heat waves in the south-eastern United States, Europe and China. This increased exposure could cause tens of thousands of additional premature deaths."

Adding to the concerns is another study, published by the Potsdam Institute for Climate Impact Research, according to which the area burned annually in Europe could triple by 2100, should atmospheric warming continue to affect the Old Continent more severely, as has been the case so far. In the dire scenario of an average temperature increase of 3.6 degrees Celsius, not only Mediterranean Europe would be at risk but also countries such as Germany, Belgium, the United Kingdom, Ireland and Sweden.