When Will the Air Quality Get Better?

[The New York Times]

Over the weekend, fast-moving wildfires continued their deadly rampage across huge swaths of California, Oregon and Washington, sending tens of thousands of people fleeing from their homes and incinerating entire communities.

At least 24 people have died — although those numbers are likely to rise as investigators and rescuers are able to access areas that may have been difficult to escape.

In Oregon, where more than a million acres have burned in some of the most dangerous infernos so far this year, officials said they were bracing for a “mass fatality incident.”

In California, the haunting images of smoldering debris and the gutting stories — like this one from The Oregonian, about a man’s desperate fight to save his family — feel familiar after years of increasingly destructive wildfire seasons.

But what has continued to astonish experts is the unprecedented scale of the fires this year.

On Friday, Gov. Gavin Newsom gave his usual virtual news briefing standing among trees charred by the raging North Complex Fire, in the midst of a yellowish haze.

He sounded a dire warning about the realities of climate change and railed against federal leaders who he said were falsely denying its realities.

“California is America in fast forward,” he said. “What we’re experiencing right now is coming to communities all across the country.”

While the governor acknowledged that poor forest management over decades has contributed to the severity of wildfires in recent years, he said that mega-droughts and record-breaking heat waves were undeniable evidence that many of the extreme predictions about climate change had already come true.

“My 4-year-old has moved from talking about a novel coronavirus — his actual words — to asking me why he can’t play around outside with a soccer ball,” he said. “That’s not the world that I want to leave to our kids.”

Millions of Californians were effectively homebound by toxic air over the weekend in a grim preview of the months that could be ahead. It’s still only September, after all.

In my Los Angeles neighborhood, I could smell and feel the smoke in my throat during a short walk down the block on Saturday. A sooty film had settled on the trees and cars, and the sun was visible as a glowing red circle in a gray-brown sky.

A look at PurpleAir’s map was a depressing exercise; few of the outdoor monitors in California registered less than 100 on the Air Quality Index.

Late last week, I asked Edward Smith, a forest ecologist with the Nature Conservancy, how long the fires might burn.

“In many cases, the fires will burn until they run out of fuel or the winter rains come,” he said in an email. Running out of fuel can mean running into physical barriers like granite or bodies of water, or irrigated pastures.

Although meteorologists said the weather was expected to help in coming days, Mr. Smith said, “it could still be several weeks, especially when suppression forces within states and across the West are drawn down to such low levels.”

Dr. Mary Prunicki, the director of air pollution and health research at Stanford University’s Parker Center for Allergy and Asthma Research, told me that so many variables affect air quality that it’s practically impossible to predict when and where the air will be safe.

“In the past, it hasn’t looked so dire so quickly,” she said. “It’s pretty scary — and it combines with the Covid-19 pandemic. It’s a layering effect.”

Research has clearly shown that the health impacts from wildfire smoke can be seen immediately in things like cardiac and respiratory distress calls.

And prolonged exposure is bad. That’s one reason fires disproportionately hurt already vulnerable populations; lower-income people are more likely to live in places where air quality is bad all the time, like the Central Valley, which has long had some of the nation’s worst air.

But on the flip side, Dr. Prunicki said, air quality can improve quickly and the dangers can ease quickly, too — “even in an afternoon.”

So in order to determine whether it’s safe to go outside, she recommended checking the Air Quality Index before you leave.

And even if air quality is not listed as dangerous, Dr. Prunicki emphasized that you may still feel negative effects.

“There are arguments that cutoffs should be tighter and more specific for different groups, but it’s pretty vague,” she said. “It’s important to listen to your body.”

By Jill Cowan