Air quality: Experts recommend precautions, not panic
Originally published September 21, 2012 at 10:55 a.m., updated September 21, 2012 at 11:20 a.m.
Counting particles: health advisers average it out
By Jefferson Robbins
World staff writer
Anthony Wexler had some oft-heard advice for NCW’s smoky air sufferers Thursday — take it easy, lay off the chores, don’t get your pulse up.
“People should stay inside as much as they can,” said Wexler, director of the Air Quality Resource Center at the University of California-Davis. “They should think about leaving town if they can.”
Then he was told a specific number: Cashmere’s fine particle count of 741 micrograms per cubic meter of air as of 9 a.m.
“Oh my God,” he said. “That’s awful. That’s off the charts.”
The town’s air monitor would later register a late-morning high of 920. For the day, Cashmere averaged 554.
The daily highs are alarming in NCW’s smoke-affected areas, but health officials say a longer view is necessary. State epidemiologists base health recommendations on 24-hour averages, because the effects of fouled air are generally cumulative rather than immediate, said Joye Redfield-Wilder, spokeswoman for the Department of Ecology’s central Washington office in Yakima.
“If a 24-hour average shows that we’re in a hazardous level according to our range of how we measure air quality, and it remains in that hazardous zone for 24 hours, we want to be as protective as possible for the citizens of the state of Washington,” she said.
Washington’s air quality standards are stricter than those promoted by the federal government. Where the U.S. Environmental Protection Agency starts its particulate danger zone (“unhealthy for sensitive groups”) at 40.5 micrograms per cubic meter of air, the Washington Department of Ecology marks that range at 20.5 to 35.4. The state’s lower cutoff for “hazardous” air quality — 135.4 micrograms or more — is just over half the EPA’s level of 250.4.
Since Sept. 10, when Wenatchee’s 24-hour average particle count first verged into “unhealthy” territory, it’s climbed into the hazardous range and refused to lapse back. Through Thursday, the average 24-hour particle count in Wenatchee was 304.3 micrograms. The average in Cashmere, since the Western Regional Climate Center in Nevada began collating measurements there Sunday, was 448.94.
“If during that whole 24-hour period you’re in a hazardous zone, we want people to pay attention to it,” said Redfield-Wilder.
So while that 920 microgram high for Cashmere Thursday strikes a fearful note, it’s the daylong average particle count of 554 that’s then held up to the Washington Air Quality Advisory scale — a color-coded rating of zero to 500 that resembles the federal Air Quality Index, but again is stricter.
Either way you slice it, Cashmere and much of the remainder of NCW wind up in hazardous territory. Fine particles 2.5 micrometers or smaller are easily trapped in the lungs and are linked to numerous health problems.
So what’s in our smoke? “It’s mostly organic and black carbon,” said Wexler, who’s studied major air pollution events including the Canadian wildfire smog that blanketed the East Coast in 2000. “Sometimes these fires look black or brown, sometimes they look very white, and the white means that it’s mostly an oily carbon. There’s other minerals in there too, like potassium, that naturally occur inside of woody plant material.”
Jefferson Robbins: 664-7123
WENATCHEE — There’s no strong evidence of long-term health effects from breathing the kind of smoky air that’s been trapped in Wenatchee for over a week.
But even people with no prior history of pulmonary or cardiovascular issues can have problems — some say even life-threatening episodes — from breathing in the fine particles now trapped in the Wenatchee Valley.
“People should be concerned, but not overly alarmed,” said Dr. Joel Kaufman, a professor of environmental and occupational health at the University of Washington.
His sentiment was echoed by Dr. David Daniel, who works in pulmonary medicine at Wenatchee Valley Medical Center and Janice Nolen, a clean air advocate for the American Lung Association.
All three agreed that people who live in the Wenatchee Valley, even those with no history of medical problems, be should taking precautions, like staying inside when possible, wearing an N-95 mask outside, and avoiding physical exertion.
The World also interviewed Anthony Wexler, director of the Air Quality Resource Center at the University of California-Davis.
Some medical professionals in Wenatchee felt an article in Wednesday’s Wenatchee World was alarmist. So The World talked to four experts, revisiting the question of how bad the smoke is, and asking what should people be concerned about.
First, as to how bad it is:
Kaufman said yes, the air in Wenatchee right now is probably more dangerous than the air after Mount St. Helens blew. It’s definitely worse than the air in Los Angeles, but difficult to say if it’s worse than living there for a year, he said.
He said it’s really not known whether the short-term exposure to high levels of particles in the air is worse than a lifetime of smoking. Cigarette smoke is probably worse, but smokers don’t breathe in smoke all day, every day, he said, adding, “I do think a lifetime of smoking is going to have a lot more serious effects for most people than a couple of weeks of these air pollution levels.”
Wexler said that breathing air sullied with burned plant matter is like cigarette smoking, but less intense. Burning plant matter of any kind releases polycyclic aromatic hydrocarbons, or PAHs, linked to cancer, but the exposure at valley level is far less than smoking. A 1992 study found that pack-a-day smokers of unfiltered cigarettes take in 2 to 5 micrograms of PAHs daily.
“Think about having one of these forest fires, but you’re one of the firefighters in it,” Wexler said. “... They’re getting these kind of concentrations that are comparable to smoking cigarettes. But even these high concentrations that you’re getting in your community, they’re still much lower than cigarette smoke.”
Daniel said he doesn’t think it was fair to compare the 10-day inversion in Wenatchee to London’s Great Smog of 1952, because coal smoke is far different from wood smoke.
“They’re different animals. The problem is, coal dust is not vegetation,” he said.
The four-day toxic cloud settled on London during a temperature inversion, killing 4,000 people and sickened 100,000 more. The culprit was coal smoke containing sulfur dioxide, which constricts breathing and oxidizes in the atmosphere to create sulfuric acid. Twenty people died in a similar event in Donora, Penn., in 1948.
Wexler basically agreed: “There is sulfur inside plant material and biomaterial,” Wexler said, “but it’s a much lower concentration.”
But Nolen said it’s a myth to think that just because woodsmoke is natural that it’s somehow less dangerous.
She contends that many studies on the issue, which include studies on woodsmoke and wildfire smoke, indicate that it’s the size of the particles more than whether it comes from woods or coal smoke or dust, that drives the risk. “The bottom line is, none of them are safe,” she said.
As for what people should be concerned about:
Going to school: “You shouldn’t be having PE if the kids are in school, but knowing kids, I also don’t think the parents are just keeping them home locked up indoors either,” Wexler said. “So school might be a better thing for them, because at least they’ll be indoors doing something that’s real sedentary, doing math or English or whatever it is, and not running around outside.” Indoor physical education, he said, might be inadvisable: “Even though the concentrations are lower indoors, they’re still going to be too high.”
Kids: Kaufman said children, especially young ones, should stay inside, and if they show symptoms, like coughing or having trouble breathing, “I would have a low threshold in leaving the area.”
People who have to work outside: “I don’t think it’s absolutely mandatory for a healthy person” to wear a mask, Kaufman said. “But if they have a pre-existing condition, maybe working outside during an event like this is not a good idea.”
Everyone: Daniel said the lack of sleep from smoke is an issue for everyone. “We all know that if we don’t sleep well, we wake up tired and get cranky and irritable,” he said. But as any medical problem it can also trigger medical problems, such as headaches.
Nolen said people should also be aware that, even if they have no history of lung or heart problems, they can suffer a sudden heart attack or stroke triggered by the smoke.
She said studies show that breathing these levels of particulates in the air can result in premature deaths. “I’m not saying people are going to drop dead tomorrow,” she said, adding, “The problem may not show up immediately. It may show up days or months afterwards.”
But Daniel countered that Wenatchee’s population may not be statistically significant enough for the smoke to result in even one premature death.
Kaufman and Daniels said if a heart attack or stroke is triggered by the smoke, those people probably already had a medical problem, they just weren’t aware of it.
“The stress of any event can trigger it,” he said, adding, “Before this fire, we all made lifestyle decisions that probably have a greater influence on our time of death.”
K.C. Mehaffey: 997-2512
Air quality readings
Airborne particle pollution in NCW communities, measured in micrograms per cubic meter (ug/m3).
Wenatchee, Alaska Street
Thursday average: 482 ug/m3, hazardous
High: 678.7 ug/m3, 11 p.m.
Low: 295.1, 9 a.m.
Confluence State Park
Thursday average: 238 ug/m3, hazardous
High: 538 ug/m3, 10 p.m.
Low: 145 ug/m3, 9 a.m.
Thursday average: 554.3 ug/m3, hazardous
High: 920 ug/m3, 12 p.m.
Low: 254 ug/m3, 6 p.m.
Thursday average: 82.3 ug/m3, very unhealthy
High: 178.5 ug/m3, 9 p.m.
Low: 26.6 ug/m3, 9 a.m.
Thursday average: 137 ug/m3, unhealthy
High: 180 ug/m3, 7 p.m.
Low: 103 ug/m3, 1 a.m.
Thursday average: 77.2 ug/m3, unhealthy
High: 96 ug/m3, 9 p.m.
Low: 49 ug/m3, 7 a.m.
Forecast: Continued hazardous levels in the Wenatchee Valley north to Entiat and very unhealthy ratings for Leavenworth and Chelan over the next few days.
Thursday average: 12.9 ug/m3, good
High: 22.1 ug/m3, 4 p.m.
Low: 8.2 ug/m3, 11 a.m.
Thursday average: 42.6 ug/m3, unhealthy
High: 64.4 ug/m3, 7 p.m.
Low: 25 ug/m3, 5 p.m.
Thursday average: 50 ug/m3, unhealthy
High: 73.5 ug/m3, 8 p.m.
Low: 22.1 ug/m3, 11 a.m.
Source: Washington Department of Ecology, Western Regional Climate Center
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