The far-reaching impacts of wildfire smoke – and how to protect yourself

The air we breathe can have profound effects on our physical and mental health. Is there any way of protecting yourself from this pervasive problem?

More than 25% of the US population is exposed to air considered “unhealthy” by the Environmental Protection Agency (EPA), according to a report by the climate non-profit First Street Foundation. By 2050, the number of people exposed to “unhealthy” days is set to increase by more than half. The worst days of air pollution (“hazardous” or maroon, under the EPA’s system) are expected to rise by 27%.

As climate change makes wildfires more intense, here are some of the profound and unexpected ways air pollution affects our bodies, and what we can do to minimise exposure.

“Even if someone is far away from a fire source, they may still experience adverse health outcomes from the inhalation of highly diluted and oxidised smoke,” Athanasios Nenes, an atmospheric chemist at the Swiss Federal Institute of Technology Lausanne told Allison Hirschlag for the BBC.

There is growing evidence that air pollution not only affects our physical health, but also our mental health. It has been linked to impaired judgement, poorer performance in school and even higher levels of crime. Researchers point to prolonged exposure to pollutants such as PM2.5.

But the picture is not a simple one. Exposure to air pollution is far from equal – despite how it might seem, we don’t all breathe the same air. Often the most polluted areas in a city, for example, are in the poorest neighbourhoods. These are areas also afflicted by other problems that affect health, educational achievement and crime levels. Confounding factors such as investment in education, diet, smoking, drug use and alcohol consumption can also have an effect.

Scientists say that pollution particles trigger inflammation and slowly wear away the nerves in the olfactory bulbs, which transmit smell information from the nose to the brain.

Clean air is not an option for everyone

Almost everyone in the world now breathes air that is polluted in some way. But those who are worst hit by air pollution are also those who are least able to be able to protect themselves or escape from it. An estimated 716 million people with the lowest incomes globally live in areas with unsafe levels of air pollution. Even in the relatively wealthy, developed nations of Europe and North America, the toll taken by air pollution is borne predominantly by those who are least well off or from minority communities that face systemic inequalities.

To map the long journeys that air pollution takes in atmospheric currents, scientists rely on monitoring stations that take near constant samples of air quality. One of those is the Zeppelin Observatory above the tiny town of Ny-Ålesund in Svalbard, Norway.

This settlement, which boasts a population of just 45 people in winter and is 765 miles (1,230km) from the North Pole, grew up around the coal-mining industry in the first half of the 20th Century. Today, it has some of the cleanest air on the planet.

But that is also changing – levels of methane have been growing in the air around the town, while levels of sulphate, particulates and metals are also spiking.

Another candidate for the world’s most pristine air can be found on the north-western tip of Tasmania, Australia. Cape Grim, or Kennaook, where winds whip across the Southern Ocean unimpeded. As it doesn’t pass over any landmasses or populated areas enroute, the air is unaffected by local sources of pollution such as exhaust fumes. Learn more about Cape Grim in this feature by Dani Wright and find out more about how the air around Ny-Ålesund is changing in this feature by Anna Filipova.

Other remote clean air sites around the world include Mauna Loa station in Hawaii, Macquarie Island and Casey Station in Antarctica.

* The article was originally published on 13 February 2024. It has been updated to include details about the LA fires in January 2025.