According to local fire officials, buildings in California’s Napa and Sonoma counties were being evacuated on Monday morning, after multiple wildfires began spreading throughout the area with a thick smoke and large flames. According to the state Department of Forestry and Fire Protection, the fire was burning in the hills above Napa County and had damaged several buildings. As of Monday morning, firefighters have continued to struggle to contain the fire. Officials said dry winds were fanning the flames and asked residents in mandatory evacuation zones to leave immediately.

There’s enough wildfire activity in California and Nevada to blanket much of both states with a layer of smoke in the coming days.

In California alone more than 140,000 acres are burning in large, wildland fires throughout the state. A fire in rough terrain near Reno is also contributing to smoke in northern Nevada.

In just the past two days, fires in California’s wine country are thought to have produced as much small particulate matter as all the vehicles in the state produce in a year.

“It’s a lot,” said Sean Raffuse, an air-quality analyst at the Crocker Nuclear Laboratory at University of California in Davis.

Although the early estimates are rough, Raffuse said the fires in the wine country have probably produced about 10,000 tons of PM 2.5, an air pollutant that’s the main cause of haze in the United States.

By way of comparison, it takes the approximately 35 million on-road vehicles in California a year to generate a similar amount of PM 2.5, Raffuse said.

“Interestingly, these fuels are relatively light compared to some areas,” Raffuse said of the fires in wine country. “For example, I would expect the Redwood Valley Fire burning in Mendocino County to produce 2-3 times more smoke per acre burned.”

The amount of smoke is significant because PM 2.5 is associated with respiratory and cardiovascular problems in people.

And smoke from the thousands of structures burned in some of the fires can be even more hazardous than typical wildland fire smoke, said Jim Roberts, a research chemist from the National Oceanic and Atmospheric Administration’s Earth System’s Research Laboratory.

“It is a little bit different because they had so many structures burn, that is a different fuel mixture … a lot of that stuff has toxic emissions associated with it,” Roberts said.

The smoke and fumes will be most hazardous to the people closest to the burning, he said.

“On the local scale when that smoke stays in the area and you are exposed to it, then it can be harmful,” Roberts said. “People who fight residential fires really worry about those materials. That is why they wear respirators when they go into a house.”

Air quality data from the Environmental Protection Agency showed a large plume of dense smoke stretching from the central California coast, across the northwest corner of Nevada and into southern Oregon and Idaho on Wednesday.

Air quality forecasts in Reno, San Francisco and Sacramento predicted varying degrees of unhealthy air throughout northern California and Nevada.

Source: Air pollution from California fires equals a year’s worth of traffic, analyst says