Wildfire smoke turned air unhealthy last week

People in the Anacortes-La Conner area experienced unhealthy air quality during Oct. 18-20, when air quality worsened steadily over two days, with 24-hour average readings of 42.1 ug/m3, 101.7 ug/m3 and 40.8 ug/m3. The Wednesday, Oct. 19 air quality was rated "unhealthy for everyone" by exceeding 101 ug/m3. The other two days the air quality was "unhealthy for at-risk groups," at over 35.5 ug/m3.

The 24 hour average Oct. 16 was 34.5 ug/m3, just under the unhealthy for at-risk groups threshold.

Over 0.1 inch of rain fell in Anacortes Oct. 21, clearing the air and reducing particulate matter to 5.1 ug/m 2.5.

The National Weather Service Seattle office issued air quality alerts throughout the week. It reported hourly readings, for example "Particulates in the air near La Conner peaked with a reading of 90 PM 2.5 at 4 p.m. Oct. 16," That level is unhealthy for everyone. On Oct. 14 NWS issued a 68 hour alert, which it extended daily through Oct. 20.

The Northwest Clean Air Agency issued a Stage 2 air quality burn ban Oct. 19-20, ending it with the weather change Oct. 21 and air quality improving as winds cleared out wildfire smoke.

The first two weeks of October, air quality for each 24 hour period was generally good, below 12.0 ug/m3. The 24-hour air quality dipped to moderate Oct 7 and 14 with readings at 13 ug/m3.

The concentration of an air pollutant is given in micrograms (one-millionth of a gram) per cubic meter air or ug/m3.

PM2.5 refers to atmospheric particulate matter (PM) that have a diameter of less than 2.5 micrometers, about 3% the diameter of a human hair.

Data are from the NWCAA station in downtown Anacortes. The agency's region is Island, Skagit and Whatcom counties.

As for livestock, Chelsy Mesman of Mesman Farm reported, "We didn't see too much of an effect on the cows. They were still out enjoying the pasture and going about their day regularly. The smoke still can irritate their lungs, but we were watching them closely and didn't see any drop in milk production that would indicate stress on them."

In Bow, Jessica Gigot of Harmony Fields Farm reported, "Our sheep were all right in the smoke, but we tried to keep them close to the barn. The new smoke season is affecting when we dry off our sheep from milking because we don't want to be stressing their systems in poor air quality."

If the smoke had lasted longer? "We probably would have seen a definite drop in milk production because of the stress and it would be harmful to their respiratory system," Mesman said. Long term smoke is not good for any living creatures.