Did you wake up to falling ash? You may want to head back inside, air officials say

If you woke up to find a dusting of ash your car this morning, you weren’t the only one.

The Detwiler Fire in Mariposa County is dropping ash on the central San Joaquin Valley and coating not only cars, but lungs, according to the San Joaquin Valley Air Pollution Control District.

A health caution issued by the district was set to end on Tuesday because most of the nearby fires are wrapping up, said district spokeswoman Cassandra Melching. But there’s one fire that may cause the district to extend the alert. “The one that’s giving us a lot of grief is the Detwiler Fire,” Melching said. The fire began Sunday near Lake McClure east of Modesto and left Valley skies looking hazy Sunday evening and Monday morning.

Taking a look at the district’s air monitors, data seem to indicate there are minimal health risks, she said. But it’s only because monitors detect fine particulate matter, which can’t be seen by the naked eye. This time, the danger lies in what you can see, said Melching.

“Ash is a lot larger,” she said. “We tell people, if you can see and smell smoke and see ash falling, treat it as a level four or five. Stay indoors in that cool filtered air.”

Smoke and ash particles can enter eyes or lungs and cause burning, a runny nose and other respiratory illnesses, the district said. Those with chronic heart or lung diseases are more susceptible. Air quality tends to get worse in the afternoon, Melching said.

A two-week long heat wave is also not helping Fresno’s air. Wednesday might break that streak with a high of 99, said meteorologist Cindy Bean with the National Weather Service in Hanford. Upper 90s are expected throughout the rest of the week, but will rise again into the triple digits on Saturday and Sunday, she said.

Melching said wildfires, bad air quality and even raining ash are a normal part of summer in the Valley. “We’re surrounded by mountain ranges,” she said. “This is what we get.”

This story was originally published July 17, 2017 at 1:23 PM with the headline "Did you wake up to falling ash? You may want to head back inside, air officials say."