LOS ANGELES — Electric cars really do reduce air pollution and boost public health, according to a new study. Researchers from the University of Southern California (USC) say asthma attacks and other respiratory problems fall as more people switch to vehicles which produce zero emissions. The findings come from the first “real world study” of its kind, looking at the controversial vehicles’ impact on individual neighborhoods.
“When we think about the actions related to climate change, often it’s on a global level,” says study lead author Erika Garcia, PhD, MPH, an assistant professor of population and public health sciences at USC’s Keck School of Medicine, in a media release. “But the idea that changes being made at the local level can improve the health of your own community could be a powerful message to the public and to policy makers.”
Researchers say there have been claims that the heavier motors will increase carbon emissions, offsetting the gains of switching from gas and diesel engines to electric. Electric cars are typically about 20 to 30 percent heavier than their gas or diesel-powered counterparts. The theory suggests that wear from brake linings and tires may be greater in electric cars than with traditional vehicles because of the weight of their battery — generating more harmful fine particles.
How much do electric cars clean up neighborhoods?
Leveraging publicly available datasets, the researchers analyzed a “natural experiment” as residents in California rapidly transitioned to electric cars, or light-duty zero emissions vehicles (ZEVs). At a zip code level, for every additional 20 vehicles per 1,000 people, asthma emergencies dropped by 3.2 percent. Federal air monitoring sites showed levels of nitrogen dioxide (NO2), an air pollutant caused by traffic, also fell.
As average ZEV adoption increased from an average 1.4 to 14.6 per 1,000 people within a given zip code between 2013 and 2019, local air pollution levels and emergency room visits fell. Asthma is one of the health concerns with a long connection to air pollutants such as NO2, which can also cause and exacerbate other respiratory diseases, as well as problems with the heart, brain, and other organs.
However, the researchers also found that adoption of electric vehicles was considerably slower in low-resource zip codes — with the team calling it an “adoption gap.” The scientists say this points to an opportunity to restore environmental justice in communities that are disproportionately affected by pollution and related-health problems.
“The impacts of climate change on health can be challenging to talk about because they can feel very scary,” says senior study author Sandrah Eckel, PhD, an associate professor of population and public health sciences at the Keck School of Medicine. “We’re excited about shifting the conversation towards climate change mitigation and adaptation, and these results suggest that transitioning to ZEVs is a key piece of that.”
Income inequality can play a role in pollution levels
Previous research has shown that deprived individuals tend to face worse pollution and associated respiratory problems than more affluent individuals. If ZEVs replace gas-powered cars in those neighborhoods, they could stand to benefit substantially, the study says.
“Should continuing research support our findings, we want to make sure that those communities that are overburdened with the traffic-related air pollution are truly benefiting from this climate mitigation effort,” Garcia adds.
Global warming is a massive global health threat. Mitigating this offers a huge public health opportunity, Prof. Eckel says. The team adds that future studies should consider additional impacts of ZEVs, including emissions related to brake and tire wear, mining of materials for their production, and disposal of old cars.
The researchers also hope to study additional types of pollutants and other classes of vehicles, in addition to conducting a follow-up study on the effects of the ever-growing share of ZEVs in the state.
They obtained data on ZEVs, which include battery electric, plug-in hybrid, and hydrogen fuel cell cars, from the California Department of Motor Vehicles. Researchers calculated a neighborhood’s socioeconomic status using the proportion of residents with a bachelor’s degree. Moving forward, transitioning to ZEVs is just one part of the solution, Prof. Eckel says. Shifting to public transport and active transport, including walking and biking, are other key ways to boost environmental and public health.
The study is published in the journal Science of The Total Environment.
South West News Service writer Mark Waghorn contributed to this report.