As kids head back to school in the Central Valley of California, air quality managers say the air can become more unhealthy.
The San Joaquin Valley has some of the most unhealthful air in the state, primarily because of ground-level ozone caused by vehicle emissions.
Anthony Presto with the San Joaquin Valley Air Pollution Control District says, as more schools open, the air quality can worsen.
"When kids get out of school it's the worst part of the day, where the sun is at its highest and hottest, and ozone has built up to just about its maximum level for the day," says Presto. "And you have parents idling their vehicles as they're waiting for their children to get out of school."
Presto says idling vehicles can actually push air quality into unhealthy levels in the Central Valley, which already has significant ozone pollution.
"Idling your vehicle actually can sometimes put us over the edge when we're trying to keep air quality clean and trying to avoid exceeding national air quality standards," says Presto. And idling does make a difference."
He says people should turn off their engines when picking up kids at school to reduce ozone and noxious fumes.
Presto says the increased emissions could bring Air Alerts in the Central Valley, especially during periods of high temperatures and stagnant air.