Thousands of people biked, skated and walked the streets in and around downtown Los Angeles Sunday, breathing in the fresh air — at least, fresher air.

In a study released Monday, researchers at the UCLA Fielding School of Public Health said events like CicLAvia — in which residents are encouraged to ditch their cars and use alternative forms of transportation, such as public transit, biking or walking — may actually improve local air quality.

L.A.'s air quality is notoriously bad, and research has shown that fumes from all of the vehicles choking our streets increase residents' risk for respiratory and cardiovascular disease, researchers said.

The study's authors looked at last October's CicLAvia in downtown L.A. and found that air pollution was significantly reduced along the route and even on other streets in the communities where the event was held.

The route studied was similar to the one held this past weekend and included the neighborhoods of Echo Park, Chinatown, Boyle Heights and East L.A.

"Downtown and East Los Angeles, in fact, are among the California communities with the worst environmental conditions according to an Office of Environmental Health Hazard Assessment report; both rank among the state's bottom 10 percent," the researchers said in a prepared statement.

The researchers took air quality samples along the closure route and compared those to samples taken at the same locations in the weeks before and after the event.

They found the level of particulate pollution during the event was nearly half what it was on days with normal vehicle traffic.

There was even a 12 percent drop in surrounding streets still open to cars.

The researchers acknowledged the sample size was small and that more testing is necessary to confirm their findings, but they said the results — published in the journal Environmental Pollution — underscore the amount of air pollution coming from cars and trucks.

The study's authors said efforts to encourage cleaner forms of transportation can only help public health.