Wildfire dropping ash in Merced County. Here’s what you need to know about the air

The air in Merced, which is bad on its best days, could get worse in coming days as a number of wild fires burn around the Valley, according to the San Joaquin Valley Air Pollution Control District.

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

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. The Detwiler Fire remains the outlier.

The fire began Sunday near Lake McClure and left Valley skies looking hazy Sunday evening and Monday.

The district’s air monitors 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.

The danger lies in what you can see, according to Anthony Presto, a Merced-area spokesman for the air district. “What we’re advising the public is if you see smoke or ash, you should try to remain indoors,” he said.

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.

The Merced area should get a slight respite from its three-digit heat in the coming week, according to William Peterson, a meteorologist technician with the National Weather Service in Hanford. Upper 90s are expected throughout the rest of the week, but could rise again past 100 on Saturday and Sunday, he said.

The winds have remained light, he said, so most of the smoke and ash have fallen in the foothills.

Presto noted much of the Valley does not meet federal air standards.

“(Air) does tend to be a little worse in Fresno and the Bakersfield, Kern County area,” he said. “Modesto and Merced are in a similar range.”

This story was originally published July 17, 2017 at 5:05 PM with the headline "Wildfire dropping ash in Merced County. Here’s what you need to know about the air."