Is massive Tracy warehouse fire impacting California air quality?

Smoke from a large warehouse fire in Tracy is not expected to move over the Bay Area, public health officials say, but it could threaten people in the San Joaquin Valley, especially if smoke moves closer to ground level.

“At this point, we are not seeing any significant air quality impacts on the ground, but of course, the fire is still burning, so that could change,” said Jamie Holt, chief communications officer with the San Joaquin Valley Air Pollution Control District.

Winds pushing from west to east kept the air quality index in the good to moderate categories in the Bay Area on Friday afternoon. That general wind pattern is expected to continue through the weekend as crews attempt to extinguish one of the nation’s largest warehouse blazes of its kind.

In the San Joaquin Valley, the air quality index was generally in the moderate category, but because of ozone, not smoke.

Smoke remained higher in the atmosphere Friday, but may encroach on ground level in the coming days, particularly at night, Holt said. The Valley Air District installed two temporary air quality sensors near the site and continues to monitor shifts in weather and smoke.

“We’ve been fortunate it’s staying aloft and we’re hopeful that it will continue to stay aloft as it dissipates down along the east side of the coastal range and then down into the central and southern San Joaquin Valley,” Holt said.

Smoke particulates smaller than a human hair posed the biggest danger to human health, but Holt said other toxic substances mixed with the smoke plume also may be hazardous.

“The California Air Resources Board is taking a more critical look at what was burned and is continuing to burn to see if there’s any additional risk,” Holt said. “The good thing is that if there is a risk, it’s going to be moving with the smoke. They’re kind of all mixed together.”

Holt recommends people create a clean air room in their house with closed doors and an air filter in case smoke begins to fumigate valley cities.

Residents in San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare and Kern counties are encouraged to monitor the San Joaquin Valley Air Pollution Control District website. People in Alameda, Contra Costa, Santa Clara and other Bay Area counties should check the Bay Area Air District website.