ast-charging hubs for electric vehicles (EVs) in Los Angeles County have been found to emit levels of fine particulate matter twice as high as surrounding urban areas, according to a study by researchers at the University of California, Los Angeles.
The research, published in the paper ‘Fine particulate matter emissions from electric vehicle fast charging stations’, analyzed filter samples from 50 DC fast charging stations across 47 cities. Daily PM2.5 concentrations ranged from 7.3 to 39.0 micrograms per cubic meter, significantly higher than urban sites without fast chargers, which showed concentrations of 3.6 to 12.4 micrograms per cubic meter. PM2.5 refers to microscopic particles that can pose health risks when inhaled.
Yuan Yao, the study’s lead author, said the elevated pollution is not directly caused by the chargers themselves but may result from engineering factors within the power cabinets. “Our findings suggest that these tiny particles likely come from particle resuspension around the DCFC’s power cabinets. The cabinets convert electricity from the grid into the direct current needed to charge EV batteries. 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,” Yao explained.
The study found that the high particulate levels were largely confined to areas immediately around the chargers, with concentrations dropping substantially just a few meters away and returning to background levels a few hundred meters from the station. Nonetheless, researchers cautioned that exposure could be a concern for drivers using the charging stations.
The research team recommended modifications to the power cabinet cooling systems and the installation of filters to reduce particle resuspension. Additionally, they suggested placing DC fast-charging stations away from densely populated areas, schools, nursing homes, and other sensitive locations to mitigate public exposure.