EVs are already making your air cleaner
The logic that electric vehicles benefit public health has long been sound: more electric vehicles means fewer internal combustion engines on the road and a reduction in harmful tailpipe emissions. But researchers have now confirmed, to a large extent, that this is indeed what is actually happening on the ground. Additionally, they found that even a relatively small increase in electric vehicle adoption can have a measurable positive impact on a community.
While previous work relied largely on modeling, a study published this month in the journal Lancet Planetary Health used satellites to measure actual emissions. The study, conducted between 2019 and 2023, focused on California, which has one of the highest rates of electric vehicle use in the country, and on nitrogen oxide, one of the gases released during combustion, including when fossil fuels are burned. Exposure to the pollutant can contribute to heart and lung problems and even premature death. Across nearly 1,700 ZIP codes, the analysis showed that for every 200 increase in electric vehicles, nitrogen oxide emissions decreased by 1.1 percent.
“A small addition of cars at the ZIP code level led to a drop in air pollution,” said Sandrah Eckel, a professor of public health at the University of Southern California’s Keck School of Medicine and lead author of the study. “It’s remarkable.”
The group had previously attempted to establish this link using Environmental Protection Agency air monitors, but because there are only about 100 in California, the results were not statistically significant. The data also covered the period 2013 to 2019, when there were fewer electric vehicles on the roads. Although the satellite instrument they ultimately used only detected nitrogen oxide, it allowed researchers to collect data for virtually the entire state, and this time the results were clear.
“It makes a real difference in our neighborhoods,” said Eckel, who said a methodology like theirs could be used anywhere in the world. The advent of such powerful satellites allows scientists to also examine other sources of emissions, such as factories or homes. “It’s a revolutionary approach.”
Mary Johnson, who researches environmental health at Harvard University’s TH Chan School of Public Health and was not involved in the study, said she was not aware of a similar study of this size, nor one using so much satellite data. “Their analysis seems robust,” she said, noting that the authors controlled for variables such as the COVID-19 pandemic and the shift toward working from home.
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The findings, Johnson added, “make perfect sense” and align with other research in this area. When London implemented a congestion charge in 2003, for example, it reduced traffic and emissions and increased life expectancy. This is also the direction that this latest research could take. “They haven’t taken the next step and looked at the health data,” she said, “which I think would be interesting.”
Daniel Horton, who leads Northwestern University’s climate change research group, also sees value in this latest work. “The results help confirm the type of predictions made by numerical air quality modelers over the past decade,” he said, adding that they could also lay the groundwork for similar research. “This proof of concept document is a good start and bodes well for things to come. »
Eckel hopes that eventually, advances in satellite technology will also enable more widespread detection of other types of emissions, such as fine particles. It could even help explain some of the potential downsides of electric vehicles, which are heavier and therefore could kick up more tire or brake dust than their gas-powered counterparts. Overall, though, she thinks the image overwhelmingly illustrates how driving an electric car is better not only for the planet but also for people.
Research like this, she says, highlights the importance of continued adoption of electric vehicles, whose sales have recently fallen, and the need to do so equitably. Although low-income neighborhoods have historically been hit hardest by highway and traffic pollution, they can’t always afford the relatively high cost of electric vehicles. Eckel hopes research like this can help guide policymakers.
“There is concern that some of the communities that will benefit most from reduced air pollution are also those that are at real risk of being left behind in the transition,” she said. Previous research has shown that electric vehicles could alleviate harms such as asthma in children, and detailed data like this latest study can help highlight both areas where more work needs to be done and what is working.
“It’s really exciting that we were able to show that there were these measurable improvements in the air that we all breathe,” she said. Another finding, perhaps encouraging, is that the median increase in electric vehicle use over the course of the study was 272 per zip code.
This, says Eckel, means there are many opportunities to make our air even cleaner.
