San Joaquin Valley Air Pollution Control District Officials are reminding residents to check before using their residential wood burning devices as the weather turns colder. During winter, the largest source of particulate pollution comes from residential wood burning. “The ‘Check Before You Burn’ program provides an opportunity for Valley residents to do their part to help reduce air pollution and improve public health throughout the San Joaquin Valley,” said Seyed Sadredin, the District’s executive director and air pollution control officer.