Rule 4901, the pioneering residential wood-burning regulation which the San Joaquin Valley Air District was first in the state to adopt, returns to active duty on Nov. 1 for the 10th “Check Before You Burn” season.
The rule, which requires that residential wood burning be curtailed in each Valley county forecast to be in danger of exceeding the federal health standard for fine particulate matter (PM2.5), is recognized for reducing PM2.5 levels since 2003.
It is also credited as playing a major role in the Valley’s PM10 attainment in 2006.
Residential wood burning is the largest source of PM during winter months, emitting an average of 17 tons per day Valley-wide.
Stagnant winter conditions in the Valley keep PM at ground level, often building to high concentrations. Exposure can cause lung infections, aggravate asthma, and increase the risk of heart attacks and strokes.