Electric cars are increasingly common due to their potential environmental benefits, but a new study suggests that high levels of pollutants may cluster around fast-charging stations.
Levels of fine particulate matter (PM2.5) in the air near 50 electric vehicle fast-charging stations across Los Angeles County were significantly higher than those measured at urban sites used for comparison, according to research in the July issue of Environment International.
“For anyone, exposure to fine particles can contribute to health issues, and for those with existing conditions or heightened sensitivity, the risks are even greater,” said study author Michael Jerrett, a professor at UCLA Fielding’s Department of Environmental Health Sciences.
“Because these particles are so small," he warned in a news release, "They can travel deep into your lungs and even enter your bloodstream — potentially leading to serious problems like heart or lung disease.”
Los Angeles County had the highest number of electric car fast chargers in operation as of November 2023.
For the study, researchers checked for PM2.5 around 50 Direct Current Fast Charging (DCFC) stations in 47 cities across the county. They compared these levels to those found at gas stations and urban background sites across the county.
At the charging stations, daily concentrations of fine particulate matter ranged from 7.3 to 39.0 micrograms per cubic meter (μg/m3). Levels of 3.6 to 12.4 μg/m3 were measured at background sites, researchers reported.
Measurements as high as 39 and 34 μg/m3 were seen in cities as distant as West Hollywood and Santa Clarita, which are 29 miles apart, the study showed. Lower, but still concerning, measurements of 7.3 and 7.5 μg/m³ were found in communities including Santa Monica and Claremont.
The U.S. Environmental Protection Agency says 9 μg/m3 over 24 hours is the upper limit of PM2.5 for "good" air quality.
Unlike gasoline-powered cars, electric vehicles do not produce tailpipe emissions, which is a major source of air pollution.
But the authors noted that generating the power used to charge electric cars may create pollution.
The tiny particles likely come from the power cabinets that convert electricity from the grid into the direct current needed to charge electric vehicle batteries, researchers said.
"The cabinets also contain cooling systems to prevent the electronics from overheating, and these cooling fans can stir up dust and particles from internal surfaces," study author Yuan Yao, a UCLA Fielding scholar, said in a news release.
"Transportation electrification is vital to California's climate goals, and EV charging infrastructure plays a key role in that transition," added lead author Yifang Zhu, a professor at UCLA Fielding's Department of Environmental Health Sciences. "To fully deliver on its health promises, we must also address unintended emissions from DCFC stations to ensure that clean transportation truly means clean air for all."