On a winter with record-breaking stretches of rainless days, the Bay Area Air Quality Management District has declared a record-breaking number of Spare the Air alerts. And that in turn seems to have led to more than the usual number of complaints and criticisms.
“We hear them every day, all the time,” said Ralph Borrmann, the district’s public information officer, referring to criticisms made directly to BAAQMD officials. “So we’re well aware of them and we’re happy to speak to them, because our work is based in science.”
Many of the criticisms question the effectiveness of the district’s Spare the Air policy, which prohibits the burning of wood, pellets or other solid fuels on specified days. (First-time violators can receive a fine of $100, and the cost goes up from there.) But some say the district’s method for declaring Spare the Air days in the first place is flawed, self-serving or even conspiratorial.
So how does the Bay Area Air Quality Management District determine which days are OK for burning, and which aren’t?
To begin with: data. According to Kurt Malone, BAAQMD’s supervising air quality meteorologist, weather information is “provided to us twice daily at three hourly increments extending out 72 hours.” This isn’t just National Weather Service data, but highly detailed information from various sources on Bay Area conditions.
Then there are the district’s ambient-air sensors. These are located throughout the Bay Area, and different sensors are designed for different purposes. The ones of interest during the winter season – which for BAAQMD’s purposes extends from November to the end of February – are 12 or 13 sensors detecting “PM 2.5,” meaning particulate matter of 2.5 microns or smaller.
A particle 2.5 microns across is very small, perhaps one-60th the width of a human hair. “It’s so small that it can penetrate the blood-lung barrier,” Borrmann said, resulting in serious health problems – which is what the district is trying to guard against. And in the Bay Area, an estimated 40 percent of these tiny particles come from residents burning wood, Borrmann said.
“People make the observation that we’ve been burning wood since the Stone Age and what’s the big deal all of a sudden,” Borrmann said. The answer, he said, is that modern science makes clear what we didn’t always know: In high enough quantity, tiny particulate matter can be deadly, especially to young children and the elderly.
In the recent past, “We were not meeting federal air quality standards for particulates,” Borrmann said. “And as you, know standards get more protective over time.” Because the district’s voluntary program wasn’t working, officials started mandatory compliance in 2008 – resulting, they say, in overall cleaner air.
With this in mind, every day the district’s three meteorologists pore over – and sometimes argue over – the data in an attempt to accurately predict tomorrow’s pollution levels. They’ve been analyzing Bay Area data for more than 12 years, Malone said, looking at patterns in the way certain conditions lead to certain particulate levels.
“We have professional fights, it always stays cordial, and then we kind of chide each other the next day,” Malone said.