RICHMOND -- Air quality regulators will announce as soon as next week how much smoke pollution was found in the air after Monday's Chevron refinery fire.
The Bay Area Air Quality Management District took samples throughout Richmond and in neighboring cities Monday as firefighters battled the three-alarm blaze, which released huge clouds of black smoke thousands of feet into the sky.
The air district released test results Tuesday from eight samples they'd taken, reporting no dangerous levels of the 23 chemical compounds they tested for.
"The likely source of health impacts from the fire is particulate matter from smoke," said Lisa Fasano, spokeswoman for BAAQMD.
Regulators also took samples to test for those particulates, but they take longer to process -- at least one to two weeks -- and so the earliest results could be available is Aug. 13, Fasano said.
The chemical tests, she explained, are taken by regulators who carry canisters about the size of a gallon paint can to any given spot and collect an upwind air sample, sealing off the canister and testing the air trapped inside for chemicals.
The test for smoke particulates is more complicated because it's detected by filters mounted in place over a 24-hour period, Fasano said. The filters are then dissolved in a chemical that preserves the bits of particulate themselves, and those are then dried and examined.
Fasano also corrected the district's mistaken report Tuesday that there were no significant chemical levels found in any of the eight tests taken.
One sample, taken by county health workers in El Cerrito at Arlington Boulevard and Potrero Avenue, found a higher-than-reported level of acrolein.
Acrolein is commonly found in car exhaust, cigarette smoke and overheated cooking oil or grease, according to the Center for Disease Control. At low exposure levels, it can cause watering eyes, difficulty breathing and burning in the nose and throat, and at high levels can be fatal.
Acrolein has not been regulated by the state or the Environmental Protection Agency, but the federal Occupational Safety and Health Administration requires that work environments for workers exposed to the chemical for 40 hours a week have no more than 100 parts per billion.
The level found in El Cerrito Monday was well under that at 3.2 parts per billion, Fasano said.
The air district didn't initially report that, she added, because that level still falls within everyday varying levels seen in the Bay Area, which commonly range as high as 4.5 parts per billion.
Area hospitals reported hundreds of patients coming for treatment in the wake of the fire and complaining of sore throats, nausea and breathing problems. A local law firm told reporters it had more than 1,000 people sign up to file claims against Chevron.
Contact Sean Maher at 925-943-8013. Follow him on Twitter at twitter.com/OneSeanMaher.