In the “Smoke Belt” of the U.S. West, climate change making it harder to breathe – “Over the past two days we’ve experienced unprecedented levels of air pollution”

Desdemona Despair

By Megan Molteni
12 October 2017

(Wired) – No one knows what sparked the violent fires ablaze in the hills of California wine country. In the last five days, the flames have torched more than 160,000 acres across Napa and Sonoma counties, reducing parts of Santa Rosa to piles of cinder and ash and leaving more than 20 dead and hundreds missing. And far from the white-hot embers of destruction, residents from San Francisco to Sacramento to Fresno have been waking up this week to choking fumes, commuting to work under skies tinged orange with dust and soot.

Now, in just a single fire season, ash has rained down on Portland, Seattle, San Francisco, and Los Angeles. That might seem like an anomaly—but it’s more a portent of the country’s new, char-coated normal. As climate-change fuels increasingly large and frequent wildfires that hit closer and closer to densely populated urban centers, the smoke they produce is becoming a public health crisis.

“Over the past two days we’ve experienced unprecedented levels of air pollution in the region,” says Kristine Roselius, a spokeswoman for the Bay Area Quality Management District. Things cleared up slightly on Wednesday, but mercurial weather patterns make it hard to know if the worst is still yet to come. “It’s very difficult to forecast what the air quality will be at any moment because we’ve still got active fires.”

But in general, the forecast is not good. Roselius says they’re especially concerned about the elevated levels of PM2.5—very small bits of liquids and solids suspended in the air, no bigger than 2.5 micrometers across. Particles this small can be inhaled into the deepest recesses of the lungs, into the broccoli-shaped alveolar sacs, where they bypass the body’s filtration systems and slip directly into the bloodstream. What exactly is in those tiny droplets and specks depends on the source, the season, and atmospheric conditions. But it’s the amount of particulate matter more than the type that matters for health. […]

It’s work that’s increasingly important as more acres of American forests go up in smoke each year. “As the climate continues to change, we’re going to see much more smoke, at higher intensities in the future,” says Jia Coco Liu, an environmental health researcher at Johns Hopkins. Based on air pollution from past and projected future wildfires in the American West, Liu and a team of scientists at Yale estimated that by mid-century more than 82 million people will experience smoke waves—more than two consecutive days with high levels of wildfire-related air pollution. People in the new Smoke Belt—Northern California, Western Oregon, and the Great Plains—are likely to suffer the highest exposure. [more]

In cities, it’s the smoke, not the fire, that will get you