When bad air is worse Quirks in reporting can understate extent of pollution.

Chris Bowman

Jul. 13, 2008 (McClatchy-Tribune Regional News delivered by Newstex) -- When smoke in fire-besieged California is at its worst, the public often doesn't get to see just how bad it is.

Hourly air pollution readings on the Internet suddenly go blank for long stretches of the day. Worse, they show levels known to kill people with heart or lung disease. Smoke this bad also doesn't figure into the color-coded Air Quality Index that helps millions plan their day.

The high-end measurements are real, but state and local air officials frequently exclude the data as invalid because of a quirk in federal rules.

The results can be misleading data on the true nature of the air people breathe when multiple fires foul the skies. That happened at least twice during the recent spate of major fires that choked the Sacramento Valley and Sierra foothills.

These are among the undisclosed shortcomings of air pollution reports, according to smog officials interviewed by The Bee last week, when pollution peaked in the Sacramento region.

California Air Resources Board officials acknowledged that the exclusions of extreme smoke episodes can distort air quality data, making conditions appear better than they are. Regulators do, however, consider those unreported readings in drafting public health advisories, said Jeff Cook, who coordinates the air board's "emergency response" in smoke-choked areas.

"This is an unusual situation, and we want to see as much of the data as we possibly can," Cook said Friday.

People who rely on the news media or local air districts' Web pages for the daily pollution readings or AQI, however, are unknowingly getting an incomplete picture at a time when health risks are the most extreme.

Such was the case last week in the Sierra foothills communities of Quincy and Paradise, northeast of Sacramento.

The air board's Web site, under a database known as AQMIS, shows maximum AQI levels in Quincy on Thursday and Friday as 218 and 290, respectively.

That's within the red-colored "very unhealthy" range, meaning people with heart or lung disease, the elderly and children should avoid all outdoor activity, and everyone else should avoid prolonged exertion.

Had air officials included the worst pollution episodes on those days, Quincy residents would have learned that the air actually was more dangerous.

From 3 p.m. Thursday to 6 a.m. Friday, particle pollution from the Canyon Complex fire reached concentrations of 434 to 500 on the AQI, said Joe Fish, deputy air pollution control officer for the Northern Sierra Air Quality Management District.

"Quincy just got hammered," Fish said.

At those levels, air is considered "hazardous" -- color-coded maroon -- meaning people with heart or lung disease are at risk of dying, according to the U.S. Environmental Protection Agency, which devised the AQI. All other adults "should avoid all physical activity outdoors," and children "should remain indoors." Fortunately, most Quincy residents were presumably indoors and asleep when smoke was thickest.

Fish said he had never seen pollution levels stay so high for so long in wildfires.

He nonetheless "got rid" of the data because of technical anomalies: A newly installed air monitor in Quincy was registering the wrong year on the sampling dates, he said.

In addition, Fish said EPA pollution reporting protocols required him and any other air pollution control official in the state to scrub the data as invalid.

"That doesn't necessarily mean data was wrong or inaccurate," Fish said. "When you monitor (air quality), the EPA is very, very picky."

Officials monitoring smoke from the fire near Paradise also are excluding many of the highest pollution readings from the public database because smoke that thick begins to clog monitors.

"Some of the numbers that we're seeing that will probably be thrown out are 600, 700, 800," said Bob McLaughlin, assistant chief of the Butte County Air Quality Management District. Those concentrations all fall well within the "hazardous" range.

Accuracy isn't the issue, McLaughlin said.

"We think those numbers are real numbers -- and they are pretty close to what's going on," he said.

Cook, who manages quality control of pollution data at the state air board, agrees that readings from monitors with reduced air flow are accurate and said the data should be included in public air quality reports.

"We want to see that data for the public health advisories," Cook said.

The air flow problem with the samplers generally occurs when they pick up thick smoke from nearby fires, according to David Gobeli of Met One Instruments Inc. in Grants Pass, Ore., which supplies most of California's pollution monitors.

The model, BAM-1020, is designed to operate at more common particle pollution levels, below 100 on the AQI. At 300 and above, smoke tends to clog filters and cut the flow of air into the instrument, Gobeli said.

Outside of the EPA-specified flow range, the devices can't separate larger dust particles from smaller ones that are of greater health concern, such as from auto exhaust and wildfires.

That's important for consistency in the EPA's enforcement of national clean-air standards for particle pollution.

With wildfire smoke, however, virtually all particles picked up by monitors are the smaller ones, no matter the flow rate, Cook said.

"I don't think we are compromising our ability to make health determinations," he said.

Newstex ID: KRTB-0178-26622965