‘Spare the Air’ is actually working

Bay Area residents hear about “Spare the Air” days all the time. But do they know even what it means, or if it’s working?

Well, it is, according to the group responsible for creating and enforcing the concept.

The Bay Area Air Quality Management District is claiming that Spare the Air days — which make it illegal to burn wood other solid fuel outdoors or in fireplaces on days with poor air quality — have decreased peak levels of particulate matter.

The group’s technical service director Eric Stevenson told NBC Bay Area they have measured a decrease in peak levels of PM during the winter season:

“… and what we believe that’s caused by is the decrease in smoke that’s emitted from individuals’ fireplaces.”

Testing sites throughout the Bay Area have also indicated that there has been a drop in the average of PM over the last several years.

Cities including Livermore, Concord, Redwood City, Vallejo Santa Rosa and Gilroy experienced a significant decrease in PM. However, larger cities like San Francisco and San Jose demonstrated a minimal drop. Oakland saw a minor increase.

Berkeley environmental engineering professor Robert Harley told NBC Bay Area he believes higher fuel standards, improved motor technology and industry practices have made a bigger impact on the quality of air than a few days where wood is not being burned:

“It’s still helpful, but it has much less leverage on the annual average of particulate matter (PM), and it’s much more focused on the high winter episodes.”

The most significant drop in PM occurred during a three-year span beginning in 2000 where it fell by one-third. PM has fallen by another 22 percent since 2003.