Santa Monica airport is closed for routine maintenance on the runway this week. It re-opens on Friday morning.
Meanwhile, the Southern California Air Quality Management District is using this time to study air pollution from the airport.
Southern California AQMD spokesman Sam Atwood says when agency scientists heard about the temporary closure, they grabbed their monitoring equipment and headed into the neighborhoods near the airfield to measure two types of pollutants before, during and after the planes are grounded.
"One is called black carbon," says Atwood, "and this is kind of a surrogate or a gauge of diesel-type exhaust or jet exhaust."
The other, he says, is known as ultra fine particles – which cause concern among heath experts because they’re so tiny they can enter the bloodstream and internal organs.
The measurements will augment a previous year-long study done by agency scientists, and help regulators understand what emissions come from which aircraft.
"In the end," says Atwood, "this may suggest to the airport, to the city, FAA, methods to mitigate or reduce some of the emissions that travel into the nearby residential areas."
Atwood says the preliminary results of the study will be available to the public before the end of the year.