If the air seemed to clear recently, it isn't your imagination.
Pollution control officials say air quality is best in springtime, and on top of that, Stanislaus County residents kept the air cleaner this winter than in past years.
The San Joaquin Valley Air Pollution Control District detected only one day this year in Stanislaus County when pollution reached the level at which the district restricts wood burning. That compared to nine days last year and 16 days the prior year. Merced and San Joaquin Counties had no days compared to two and one, respectively, last year.
Anthony Presto, spokesman for the air district, said the drop is a direct result of people cutting back on wood burning. "What has become evident is that residents of the San Joaquin Valley really care and are more aware than ever before about air quality and public health," he said.
Five years ago, the district instituted its Check Before You Burn program in which people are asked to verify air quality on the district's web site at www.valleyair.org before lighting stoves or fireplaces. This year's season ended Feb. 29 and will restart Nov. 1.
Then, residents might see more no-burn days even if the air is just as good, Presto said, because air district officials will consider raising the bar for air quality in April.
Winter air pollution is generally caused by burning mixed with stagnant air. That differs from summer pollution, which Presto said is typically caused by vehicle emissions and organic compounds like gasoline fumes baked by the sun. Autumn pollution meanwhile, arises as dry conditions promote dust from agriculture and people begin using stoves to warm homes.