Air over WW County remains hazardous
The air above Walla Walla County remains at a hazardous level today, according to the Washington state Department of Ecology.
The pocket of smoke-filled air is not predicted to move out of the region until Saturday or so, said county health officials and state scientists.
Department of Ecology scientists say this is by far the worst air quality the county has seen in at least 13 years.
“This smoke isn’t clearing as quickly as we had thought,” Ecology air quality spokesman Andrew Wineke said. “... It does appear that this is the worst smoke event to hit Walla Walla since our monitor there began operating in 2007.”
Beth Friedman, a natural resources scientist with the department’s air quality program, said the site has only measured at the “hazardous” line from wildfire smoke two other times in 2017 and 2018.
Friedman said this year’s levels are “substantially higher.”
Those two events only lasted for 22 hours each, and the level of PM2.5 — the very small particulate pollution found in smoke — only peaked at a concentration of 217 micro-grams per cubic meter of air in 2017 and 233 in 2018. The current event has now lasted for about 96 hours, according the Department of Ecology’s website, with levels peaking at 437 PM2.5, well above the 2017-2018 peaks.
The poor air quality threw yet another curve ball for Dayton students. The hazardous air conditions made an already unusual school year even a little weirder Monday.
The Dayton School District is the largest district in the Walla Walla Valley to have reopened for in-person instruction amid the COVID-19 pandemic.
With safety precautions requiring masks and other facial coverings at school, Superintendent Guy Strot said ample breaks outside had been a strategy for giving students a break from their masks.
But the haze has forced them inside and masked for the whole day.
“We couldn’t let students out before school started with our usual recess before class, or for recess during mid-day.” Strot said Monday. “It was more difficult because it has been a stopgap when students have gotten tired of wearing masks. We can take them outside so they can take them off. Today we couldn’t do that.”
The Department of Community Health has extended the air quality advisory that was issued Thursday, noting with wildfire activity in Oregon and California, officials do not expect a significant improvement in conditions.
Community Health continues to recommend everyone stay indoors, take part in only light activities and keep windows closed.
Air conditioners should be run on recirculated air with the outside air intake closed off. Those who must be outside should wear N-95 respirator masks, state and local officials warned.
Earlier predictions that the smoke would move out of the region sooner did not factor in “an unanticipated strong inversion,” Department of Community Health Director Meghan DeBolt said in a news release.
Current predictions don’t anticipate that sort of air movement until Saturday.
Ecology’s smoke expert, Ranil Dhammapala, said in his blog smoke behavior is difficult to predict, but there is not much good news in sight right now.
“The ‘cleanest’ air in the state right now is ‘unhealthy’ air,” Dhammapala said Monday. “... To add to our woes, light southerly winds will continue for another day at least, dragging more smoke directly from Oregon fires northward ... So even if the ubiquitous smoke pool from offshore starts to erode a bit, a replacement is en route.”
Wineke said the state uses different levels than the U.S. Air Quality Index to measure “unhealthy” and “hazardous” levels. Wineke said the national index found at AirNow.gov may not indicate a number as high as the state’s website because the state site is aimed more at human health.
Wineke said the indexes don’t directly show actual pollution levels. The levels shown on government sites take an average over a period of time and use an algorithm to determine the threat level per hour.
Wineke also said other nongovernment websites may show dramatically higher numbers at times, but that’s because they likely measure anomalies where a particularly thick plume of smoke may have blown through for a short period of time.