EV fast chargers have a surprising health downside

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(Bloomberg) — Hundreds of public fast chargers are popping up across the U.S. to serve electric vehicle drivers seeking a cleaner alternative to gas-powered cars. But they come with a surprising risk: Charging stations create air pollution.

While EVs contribute vastly less to air pollution than combustion-powered vehicles, fast-charging stations are what a recent study called an “overlooked source of air pollution.”

The US added 703 high-speed charging stations in the second quarter, bringing the total across the country to 11,400, according to Energy Department data. Charging firms are planning to install hundreds more before year-end, making it important to address health risks now before the infrastructure becomes entrenched.

The problem “can be solved,” said Yuan Yao, a co-author of the study and a postdoctoral researcher at the University of California, Los Angeles’ Fielding School of Public Health. “We want to make sure that EV adoption is clean.”

The emissions are likely tied to the fans used in direct current fast chargers’ power cabinets. While they help keep equipment cool, the recent study indicates they likely have the unintended side effect of kicking up particles from tires, brakes and dust into the air.

Researchers took air quality measurements at 50 direct current fast charging stations in Los Angeles County, California, the majority of which were Tesla Inc. Supercharger locations. The company didn’t respond to a request for comment.

The average concentration of fine particulate matter in the air at the charging sites was 15.2 micrograms per cubic meter, slightly higher than what researchers found at gas stations and significantly higher than in other urban locations such as parks. Nearly half of the charging sites had daily fine particulate matter emissions that exceeded the World Health Organization’s air quality guidelines. (The study focused on non-exhaust emissions and therefore didn’t measure many types of pollution related to gas-powered cars.)

EV charging companies can include filtration in charging cabinets to mitigate pollution, the study’s authors said. They can also avoid putting the chargers near places like schools and residential areas.

Some companies say they’ve already taken measures to reduce the risks of particulate matter.

“On all of our current DC fast chargers, ChargePoint enforces a minimum height for the air intake and exhaust to limit the ingress of dust, debris and water,” said a spokesperson for ChargePoint Holdings Inc., which operates the largest charging network in the US. The company plans to add air filters to its “DC chargers to further reduce the risk of dust or water entering the system, or particulates being expelled.”

Gas-powered cars are still a much more potent health risk, both because of their emissions and gas stations’ environmental impact, said Joe Allen, an air quality expert and professor at the Harvard T.H. Chan School of Public Health who was not involved in the study. Research shows fueling stations are major sources of volatile organic compounds, a category of chemicals that includes the carcinogen benzene, while internal combustion vehicles produce smog-forming pollutants. Greenhouse gas emissions also adversely affect health due to their influence on climate change.

“I’d much rather be charging my EV than filling my gas-powered car at the gas station,” Allen said.

“As we expand EV charging — especially fast-charging stations — we should also pay attention to potential emissions from the charging equipment itself,” Yao said.

— With assistance from Kyle Stock.