What's different, and worse, about the smoke from the LA fires

Los Angeles is already notorious for poor air quality. But the fires burning in the area are now sending up plumes of black smoke that pose a greater threat to human health than normal wildfires.

Wildfire smoke can stay for weeks and travel across a continent.

But what sets the LA burning apart, researchers say, is the toxic mix of substances in the smoke from burning buildings, vehicles, electronics, plastics and components. other parts of the urban environment, as well as trees and other vegetation that usually burn in. the wild Here you go what is known about health risks such smoke in the short and long term:

The lungs receive the first blow

In the short term, wildfire smoke, like all smoke, inflames the lungs, says Dr Chris Carlsten, professor of medicine and director of the air pollution exposure laboratory at British University. Colombia.

But wildfire smoke has its own effects on the blood, which are thought to increase risk beyond the lungs when the blood circulates. to the heart.

Wildfire smoke contains fine particulate matter that can travel deep into the lungs when inhaled. When the lungs become inflamed, scientists suspect they send inflammatory cells into the bloodstream that affect other organs, including the brain.

Smoke can also irritate the eyes and throat leading to itching, coughing and sneezing, Carlsten says.

Acute symptoms may also include chest tightness and wheezing, a fast or irregular heartbeat and excessive fatigue. These symptoms usually easy once the fog clears, according to the University of California, Davis.

Smokey questions

Urban fires combined with wildfire smoke, like what's happening in LA, don't happen often, and scientists are just starting to study the effects.

Dr. John Balmes, professor emeritus at the University of California, San Francisco, says such urban wildfires release a cocktail of chemicals from paint, metals, plastic and other synthetic materials beyond what from burning vegetation.

Smoke from normal wildfires is “bad enough,” Barnes said. “When synthetic materials burn, they release even more toxic byproducts.”

For example, Balmes says that such fires will be released benzenea known cancer-causing agent, which researchers have traced to plastic pipes in a previous urban wildfire in California in 2018.

The health impact of exposure to wildfire smoke over several seasons is also a new topic for scientists.

Who is most likely?

When people with asthma and chronic obstructive pulmonary disease (COPD) breathe in wildfire smoke, they are at a higher risk of worsening their condition, which can lead to an asthma attack , for example. Those with lung disease are encouraged to update their medications when wildfire smoke is in the air, says Colleen Reid, an associate professor of geography at the University of Colorado Boulder who studies the health effects of exposure to air pollution from wildfires.

Because we lose some ability to tolerate or deal with short-term damage from smoke with age, older adults are also more susceptible to adverse effects, Carlsten says.

But children are also at higher risk from poor air quality during wildfires because their lungs are still developing, according to Balmes.

For pregnant women, pollution from wildfire smoke can also have an effect the fetus.

Lasting effects

What is known about the chronic health effects of wildfire smoke comes from wildland firefighters, who often work without the breathing apparatus of city firefighters.

The long-term effects on them have not been studied, however Balmes co-authored a study which ruled out harmful health effects based on the workers' exposure to fine particulate matter.

“We found that there was a higher risk of mortality from heart or cardiovascular disease and from lung cancer,” he said.

Another study by researchers at McGill University in Montreal also suggests lung and brain cancer risk associated with long-term exposure to wildfire smoke.