School hadn't quite ended when Lane Rolling pulled up to Hawthorne Elementary to pick up his son.

Most days, Rolling would leave his car running — and air conditioning blowing — while he waited.

That changed Tuesday afternoon when he arrived to find the mayors of Salt Lake City and Salt Lake County waiting for him.

The mayors surprised parents, grandparents and others picking up children from Hawthorne, 1675 S. 600 East, by greeting them outside the school and asking them to turn off their cars.

Moments earlier, Salt Lake City Mayor Ralph Becker and Salt Lake County Mayor Peter Corroon held a joint press conference at the school to kick off an anti-idling campaign, "Turn Off Your Key, Be Idle Free."

The goal is to educate people on saving gasoline and money while improving air quality by turning off car engines when idling for more than 10 seconds, Becker said.

"Most people don't think anything about idling while they're talking to someone, dropping someone off or picking somebody up," he said. "They don't even think about the fact that they're wasting gas and contributing to air pollution."

Salt Lake City, Salt Lake County and the Utah Department of Environmental Quality have teamed up to change that thinking, and they're starting at the elementary school level.

"Some of our most precious resources are our children," Corroon said, "so we thought we'd start this campaign focusing on schools and our children."

Parents oftentimes leave their vehicles idling while waiting for their children outside schools, he said, in some cases "blowing smoke right in our children's faces."

A single vehicle dropping off and picking up kids at one school puts three pounds of pollution into the air per month, according to Idle-Free Utah, www.idlefree.utah.gov. Vehicle exhaust is hazardous to human health, with children being most at risk. Asthma symptoms in children increase as a result of car exhaust.

Corroon said people need to be more aware of when they are idling their vehicles and get in the habit of turning their engines off when standing still for more than 10 seconds.

"We need to start changing our thought process about that," he said.

After chatting with Becker, Rolling said he's committed to being "idle-free."

"It makes perfect sense," said Rolling, a foot and ankle surgeon who teaches biology at Salt Lake Community College. "Pollution can affect these growing kids. We need to make sure they can be in as clean an environment as we possibly can."