Air quality officials are launching a program intended to reduce the amount of pollution kids are breathing in the San Joaquin Valley.
One source of pollution comes from parents who keep their cars running in the parking lot while waiting for their kids in the afternoon.
"What you've got there is a lot of noxious fumes that the kids are breathing in as soon as they come out of school," says Anthony Presto iwith the San Joaquin Valley Air Pollution Control District.
He says schools that sign up for the district's Healthy Air Living Schools program will be able to post "no idling" signs.
"It shows people with a car and emissions coming out of the tail pipe with one of those red circles around that picture," explains Presto, "kind of like the Ghostbusters symbol."
The district is also launching an online system that uses new equipment. It's called: Real Time Air Advisory Network, or RAAN. Presto says RAAN updates hourly.
"Because air quality does not stay the same all day long, regardless of what you see in the daily forecast, air quality changes from hour to hour."
He says RAAN allows schools to display air quality data on their homepage and helps schools make more informed decisions about whether to cancel outdoor activities.
The San Joaquin Valley has historically had some of the most unhealthy air in the state, primarily from ozone.