Below is the annual air quality data for the Roanoke region, compiled by our friend Mark Barker with the Blue Ridge Environmental Defense League.
A few comments from Mark on the significance of the data:
New ozone standard went into effect on December 28, 2015.
We had six PM 2.5 moderate, yellow days. December was second to July (11 PM 2.5 yellow days) for the most PM 2.5 yellow days in 2015.
No unhealthy, orange AQI days for either ozone or PM2.5.
88% of days were good, green AQI days
Nearly 12% of days were moderate, yellow AQI days
Only 9 ozone moderate, yellow AQI days
Ozone was the primary pollutant or tied with PM2.5 on 69% of the days.
The last Ozone unhealthy, orange AQI day was 6/29/2012 (AQI 104, ozone conc. 77 ppb).
The last PM2.5 unhealthy, orange AQI day was 6/13/2008 (AQI 141, PM2.5 conc. 59.7-60.2 ug/m3).