Environment & Science

Southland researchers measure air pollution further from freeway

Cars and trucks on the Interstate 5 near Burbank, California.
Cars and trucks on the Interstate 5 near Burbank, California.
David McNew/Getty Images

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A team of scientists led by the UCLA School of Public Health has found that the air pollution emitted by cars on the freeway extends 10 times the distance previously measured. KPCC’s Molly Peterson reports on a new study published in the journal Atmospheric Environment.

The scientists fitted up an electric car, that has no emissions, with instruments and monitors for pollution. Then during early morning hours, in winter and summer, they drove it north and south, towards and away from the 10 Freeway in Santa Monica. They found air pollutants more than 1 ½ miles downwind.

The research sponsored by the state’s air resources board also sheds light on the connection between weather conditions and where pollution goes. Even with fewer cars on the road in early morning, UCLA and USC researchers working together found pollution more concentrated around the 10 during calm winds and shallow temperature inversions, both of which move air less. That effect was even stronger in the winter, when daybreak’s later, so freeway pollution’s more dense downwind of the 10 in winter than in summer.