GENEVA: Wildfires and heatwaves, which generate microscopic airborne pollutants, risk undermining international efforts to im­­p­­­rove air quality, protect human health and safeguard nature, the World Meteorological Organisation (WMO) said on Monday.

The United Nations’ weather and climate agency underlined the links between air pollution and climate change, which scientists say is leading to more frequent and more intense heatwaves and wildfires.

“Extreme wildfires are increasing, leading to big health consequences because of the high toxicity of smoke,” the WMO said in a statement accompanying its latest annual Air Quality and Climate Bulletin.

“Whilst regulations in Europe and North America have reduced industrial and transport PM2.5 emissions, exposure to fire-related PM2.5 has increased.” Particulate matter PM2.5 is composed of microscopic particles and droplets of less than 2.5 micrometres in diameter, which is a health hazard because it can penetrate deep into the lungs and bloodstream.

It is emitted by fossil fuel-driven industrial activities, farming, domestic heating and transport, as well as by wildfires and dust storms. The report said the world needs to better monitor air pollutants such as aerosol — including black carbon and microplastics — fine particles and ground-level ozone.

These pollutants “are not sufficiently monitored even though they are widespread and are potentially harmful to ecosystems”, the WMO said. “(We need) complementary and coordinated policies on air quality and climate because they cannot be dealt with in isolation.”

Toxic wildfire smoke

“Air quality and climate change can’t be dealt with separately. If one worsens, the other does too,” Lorenzo Labrador, from the WMO’s Global Atmosphere Watch network of scientists, said. “In places where there are relatively powerful forest fires, we find a lot of fine particle pollution,” he said.

Microparticles generated by burning vegetation are “much more toxic” than those emitted by other sources, even car exhaust, he stressed. They damage the health of people and wildlife living far from the fire itself because they are carried by the wind, but their poisonous effect is not sufficiently taken into account in air quality assessments, Labrador said.

“Conventional risks models based on total PM2.5 concentrations may underestimate wildfire-attributable mortality by up to 93 percent,” the WMO said. One study cited in the WMO Bulletin says extreme fire-smoke events have tripled globally si­­­n­­­­ce the 1990s, contributing to nea­­rly 100,000 additional deaths per ye­­ar between 2010 and 2018, altho­ugh this may be an underestimate.

Ozone, microplastics

Another source of air pollution that carries major health risks is ground-level ozone, which accumulates when temperatures rise, atmospheric conditions stagnate and solar radiation is intense, as seen during recent heatwaves in China, Europe and the southeastern United States. “This increased exposure to ozone pollution has the potential to lead to tens of thousands of additional premature deaths,” particularly due to resp­­­­­iratory diseases, the WMO warned.

Another growing concern is aerosol particles, which can also travel to oceans and continents far from their source. They can alter the way the atmosphere reflects sunlight, change the chemical properties of land and water, and pollute otherwise clean environments.

Published in Dawn, September 8th, 2026