Researchers at the University of Tennessee, Knoxville, analyzed the emissions and environmental health impacts of five vehicle technologies in 34 major Chinese cities.
While electric cars have been seen as environmentally friendly, the researchers determined they are in fact responsible for more overall harmful particulate matter pollution than gasoline cars, a university release reported Monday.
The reason, they said, is because for electric vehicles, combustion emissions occur where electricity is generated rather than where the vehicle is used, and in China 85 percent of electricity production is from fossil fuels with about 90 percent of that from coal.
"An implicit assumption has been that air quality and health impacts are lower for electric vehicles than for conventional vehicles," civil and environmental engineering professor Chris Cherry said. "Our findings challenge that by comparing what is emitted by vehicle use to what people are actually exposed to."
The researchers say they discovered the power generated in China to operate electric vehicles emits polluting particles at a much higher rate than gasoline vehicles do.
In terms of air pollution impacts, electric cars are more harmful to public health per mile traveled in China than conventional vehicles, they said.
"The study emphasizes that electric vehicles are attractive if they are powered by a clean energy source," Cherry said. "In China and elsewhere, it is important to focus on deploying electric vehicles in cities with cleaner electricity generation and focusing on improving emissions controls in higher polluting power sectors."