Earth Log

Smoky September clouds San Joaquin Valley clean-air record

A Horseshoe Meadows Hotshot firefighter watches as vegetation is consumed in a burn-out operation along McKenzie Ridge in September near Kings Canyon National Park.
A Horseshoe Meadows Hotshot firefighter watches as vegetation is consumed in a burn-out operation along McKenzie Ridge in September near Kings Canyon National Park.

San Joaquin Valley folks breathed the healthiest air on record most of the 2015 summer, but a smoky September made this year a brutally memorable tale of two seasons.

For the record, the 25,000-square-mile Valley has had only 80 exceedances of the federal eight-hour ozone standard – easily the lowest total ever.

Yet the biggest air-quality news came at the end of summer, when doctors and clinics saw patient loads swell with people having breathing problems.

The breeze that helped air quality all summer had changed direction. Smoke plumes poured into the Valley from the Rough fire, which had been burning out of control since July 31 near Kings Canyon National Park.

Ash settled on windshields across the center of the Valley from Fresno-Clovis to Porterville. Asthma and bronchitis mushroomed. For people with breathing problems, it was a miserable end to summer, doctors said.

“I saw quite an increase in patients over previous years,” said Dr. Praveen Buddiga, a Fresno allergist. “It was mostly younger people with developing lungs, but it affected older people as well.”

The wildfire showed how nature can take over air quality, say officials from the San Joaquin Valley Air Pollution Control District. No emissions controls or public awareness campaigns could have stopped or slowed the soot siege.

Air authorities estimated the amount of soot and ozone-making gases was briefly 20 times higher than all other Valley air pollution sources combined. For air quality, there is no greater public health impact than particle pollution of this magnitude, says district executive director Seyed Sadredin.

“This was one of the worst summers we’ve had for particulate matter,” he said. “And remember, particulate matter usually is more of a winter-time problem.”

Before September

Drought years theoretically set the stage for bad air in summer. Federal officials have long warned that the warming climate will give ozone an ominous edge in the future.

So, in the fourth year of California’s most intense drought on record, why did the Valley have its best summer ozone season?

Air quality analysts say it was not as warm in summer 2015 as it was in the summer before. The usual high pressure that sets up the heat was just not as strong.

But June was not a part of that change. For Fresno, June was the fourth-warmest on record – even warmer than 2014. There were three weeks of bad air, which is about double the number of dirty-air days the month usually experiences.

Ozone is a corrosive gas that forms on sunny, warm, nearly windless days, combining gases from cars and fumes from gasoline, dairies and paints.

Right after the Fourth of July, the Valley began experiencing occasional cloudiness and a run of 11 days below 100 degrees. On July 9 and 10, Fresno had uncharacteristically mild 85- and 86-degree highs.

The South Coast Air Basin, which ranks with the Valley with the worst air quality in the country, had a similar July.

“Some of it may have been due to El Niño,” said meteorologist Shawn Ferreria of the San Joaquin Valley Air Pollution Control District. “We saw cloud cover, which slows down formation of ozone. It even rained a little in July.”

The pattern continued off and on through August, Ferreria says, until September. Aside from smoke, wildfires also create ozone-making gases, which drifted into the Valley.

Even though there were 15 bad days in September and five more in October, the Valley’s total of 80 bad days falls well short of the previous record, which is 89 recorded two years ago.

The Valley’s bowl shape and sometimes stagnant weather allow dirty air to remain trapped for days. No other place in the country gets as many ozone exceedances, except South Coast. Both regions are far from achieving the federal standard.

Still, a record low for the Valley would be encouraging, officials say. The long Valley ozone season is just about over.

“It is becoming pretty unlikely that we will get a lot more ozone exceedances,” Ferreria said. “The days are shorter and temperatures are coming down.”

September soot

A few days after the ash clouds descended in the Valley, children likely started feeling symptoms, doctors say. Because a child’s lungs have not fully developed, they cannot compensate for the added stress as well as an adult.

“The particulate matter is kind of like sandpaper in the lungs,” said Fresno allergist Buddiga, who represents the Fresno-Madera Medical Society. “It leads to faster, shallower breathing. It raises the risk of respiratory infections.”

In older adults, the soot often triggers bronchitis – experienced as tightness in the chest, he says.

Ozone, which spiked in September because of the fire, adds to the pain. It creates damage similar to a sunburn in the lining of the lungs.

“It’s an irritant to the lungs during summer,” Buddiga said. “The federal government on Oct. 1 lowered the threshold for ozone from 75 parts per billion to 70 parts per billion. Doctors would like to see it go below 70, but this is a step in the right direction.”

Wildfire protection

The drought made a bad situation worse in the Sierra, fire managers say. Forests are badly overgrown throughout the mountain range, and fires sometimes get out of control.

Sadredin says the district will continue to work with federal land managers to push the thinning of forests in the Sierra Nevada.

He also says the district also needs the power to continue enforcing its regulations even in a wildfire. Air regulations are currently suspended during wildfires, so the district cannot push federal agencies to quickly extinguish a fire that is harming air quality.

There were reports that federal fire managers did not attack the 151,623-acre Rough fire quickly enough in early August. Fire officials have disputed those claims, saying it was too dangerous to send firefighters into the steep terrain.

Sadredin and others at the district say the Valley has made progress against air pollution over many years. But the region needs more help in fighting pollution sources, such as wildfires or pollution from other parts of the state or even Asia, they say.

Activists have long criticized the district, saying it protects businesses and industries, avoiding stronger rules in the Valley and deflecting attention away from politicians who should be addressing human suffering.

“The air district has engaged in a campaign designed to placate the public,” said Kevin Hall, director of the Central Valley Air Quality Coalition, representing dozens of environmental, public health and medical organizations in the region.

Sadredin has responded that the district has left no stone unturned in fighting pollution, passing some of the strictest rules in the country.

He says the Valley has a long way to go before attaining federal air standards, and the public and lawmakers need to stay focused on cleaning up ozone and particle pollution.

“With El Niño coming up, people might forget,” he said. “We need to do our part to stay on the radar.”

Mark Grossi has retired from The Bee. To comment on this story:, 559-441-6330, @markgrossi