The more electric cars in a neighborhood, the lower the air pollution from burning fossil fuels, researchers studying satellite data for California found.
Conversely, satellite data also confirmed that neighborhoods that added more gas-powered cars saw a rise in pollution.
“We’re not even fully there in terms of electrifying, but our research shows that California’s transition to electric vehicles is already making measurable differences in the air we breathe,” study leader Sandrah Eckel of the Keck School of Medicine of USC said in a statement.
For every 200 zero-emissions vehicles added to California neighborhoods between 2019 and 2023, nitrogen dioxide levels dropped 1.1%, researchers reported in The Lancet Planetary Health.
The pollutant, released from burning fossil fuels, can trigger asthma attacks, cause bronchitis, and increase the risk of heart disease and stroke.
For the analysis, the researchers divided California into 1,692 neighborhoods and obtained publicly available data from the state’s Department of Motor Vehicles on the number of “light-duty” ZEVs registered in each neighborhood. These included full-battery electric cars, plug-in electric hybrids and hydrogen fuel-cell cars.
They then obtained data from a high-resolution satellite sensor that monitors NO2 levels by measuring how the gas absorbs and reflects sunlight.
The researchers said they plan to compare data on ZEV adoption with asthma-related emergency room visits and hospitalizations across California.
While the Trump administration favors gas-powered vehicles and ended tax credits aimed at promoting EVs, the report noted that a full transition to electric vehicles is projected to reduce ambient NO2 concentrations by 61% in the United States and by up to 80% in China.
Meanwhile, the new findings “show that cleaner air isn't just a theory, it's already happening in communities across California,” Eckel said.