Wildfire smoke killing thousands prematurely each year, says study

When wildfires rage, the immediate threat is obvious — but smoke from the fires actually kills far more people than the flames.

As fires become more frequent, that smoke is leading to a public health crisis.

In a study published in the journal Science Advances, it is found that wildfire smoke likely contributed to more than 52,000 premature deaths across California alone from 2008 to 2018, with an economic impact from the deaths of more than $430 billion.

Previous studies have examined the short-term health risks from wildfire smoke, but few have assessed how exposure to wildfire smoke over years adds up to shorten human lives.

Wildfire risk and severity have grown as the climate has changed and as more people have moved into the edges of wildland areas, increasing the risk that they will start fires.

Years of putting out all wildfires have also kept small fires from clearing out the undergrowth, meaning the fires that do escape have more fuel to burn.

As fires are becoming a regular occurrence in all of our lives, it’s important for communities to understand that the health risk from smoke pollution is rising, too.

Even though most fires are in rural, forested areas, smoke can travel hundreds or thousands of miles. So the health effects are widespread through population centers.

Decades of air pollution research have shown how exposure to fine particulate matter, or PM2.5, can harm a person’s long-term health.

PM2.5 is a mixture of small particles, each only a fraction of the width of a human hair. It comes from a variety of sources, such as vehicle tailpipes and factory emissions, as well as from other sources, including fires.

The particles are so tiny, they can travel deep into the lungs and even enter the bloodstream.

Inhaling PM2.5 can cause short-term respiratory health problems in vulnerable populations, such as people with asthma and older adults.

It also leads to long-term harm by contributing to the formation of chronic diseases, including atherosclerosis, asthma, decreases in lung function and diabetes. One reason this happens is the body’s inflammatory response to inhaling air pollutants.

Wildfire smoke contains a stew of chemicals.

A growing body of research indicates that wildfire PM2.5 may have unique physical and chemical components that increase toxicity.

For example, a study from the University of California, Davis, showed that wildfire smoke caused more inflammation in the lungs of rats than PM2.5 from other sources such as cars and industry.

This makes the pollutant potentially more harmful to human respiratory health compared with the typical PM2.5 that people are exposed to in urban environments.

Associated Press