The Central Valley’s season of wood-burning curtailments came to an end Feb. 28 with far fewer bans issued because of unhealthy air than in the previous year.

The San Joaquin Valley Air Pollution Control District closed the 10th season of the Check Before You Burn program with a more than 50 percent decrease in the number of burn prohibitions issued. For the 2012-13 season, the air district issued 187 curtailments Valley-wide, compared to 381 last season.

Check Before You Burn runs from November through February each winter and restricts the use of residential wood-burning devices when air quality deteriorates in order to prevent the build-up of fine-particulate matter.

During winter wood burning is the largest single source of fine particulate matter, which is a harmful form of pollution that has been linked to chronic lung disease, respiratory illness, heart attacks and premature death.

The air district cites the Check Before You Burn program as the single most-successful and cost-effective regulation. One Valley-wide curtailment results in air-pollution reductions equivalent to taking 140,000 trucks off the road, according to the air district.

“Over the past 10 years, Valley residents have come to understand the serious health consequences of residential wood burning and support this critical regulation,” said Seyed Sadredin, the air district’s executive director and air pollution control officer. “Our improving winter air quality reflects that.”

The air district called for no burn days 28 times in Stanislaus County this season. Last season’s unseasonably warm winter resulted in 51 no-burn declarations by the air district for Stanislaus County.

For the 2012-13 season Fresno County had the highest number of curtailments at 43, followed by the valley portion of Kern County at 36. Stanislaus County was third out of the air district’s eight regions. Merced County had the fewest curtailments with only 2 issued for the season.

The air district does issue fines for individuals caught burning wood on no burn days, with fines starting at $50. In Stanislaus County there were 69 violations issued this season, compared with 152 last season. Stanislaus County was third in the number of violations issued, behind Fresno County with 128 and San Joaquin at 84.

There were just three days during this winter when air quality was “unhealthy” in any county, compared to 41 such days last winter. Also, the number of days when air quality was rated “unhealthy for sensitive groups” decreased by 54 percent over last winter.

“We owe a great deal of gratitude to Valley residents for their cooperation and the resulting improvements in air quality,” Sadredin said.

The restrictions on wood-burning were initiated 10 years ago in an effort to meet federal air quality standards. The standards for when no burn days were tightened in 2008 and are expected to increase again for the upcoming season, the air district reported.