It Is Getting Worse

Air quality in the Salt Lake Valley is now what I consider to be the worst of the event thus far with the  24-hour average PM2.5 sitting at 49.1 ug/m3 compared to a National Ambient Air Quality Standard (NAAQS) of 35 ug/m3.  Hourly average values last night were not the highest of the event, but close to those seen on the 27th and 28th and certainly more sustained.

Source: Utah Division of Air Quality

Box Elder, Cache, Uintah, and Weber Counties also have 24-hour average PM2.5 above the NAAQS.  Utah County is just below it, but was above it yesterday.  Nastiness all around.

Watching the evolution of this event from the Avenues reminds me that having data from only one site in all of Salt Lake and Davis Counties is unacceptable.  For comparison, the Puget Sound Air Pollution Control Agency provides hourly real-time data from 15 sites.  We should at minimum have coverage on the benches where people often assume the air is cleaner.  Although this is sometimes the case, it's not always a good assumption. 

If you are wondering how the air can be so bad during these inversions, you might have a look at a post we did last year entitled "Your Box of Air During Inversions."  Each of us gets a cube of air about 75 yards on a side.  That's it.  Plus, an article in the Salt Lake Tribune today states that the state added another 46,000 residents last year, so the cube continues to shrink.