The majority of commuter trains in the U.S. are powered by diesel fuel. This is despite the fact that electric trains are quieter, more reliable, and produce fewer greenhouse gases than diesel locomotives. A new study has found that electric trains are healthier for passengers as well.
Caltrain carries millions of passengers a year along a 47-mile route between San Francisco and San Jose. It is the busiest commuter rail system in the western U.S. Over a six-week period beginning in August 2024, Caltrain retired all 29 of its diesel locomotives and replaced them with electric trains.
As the process began, an environmental engineering and environmental health professor at UC Berkeley noticed the rapid change in the air aboard the trains and decided to study its potential health impacts. With the support of Caltrain, he installed black carbon detectors aboard the trains and tracked the improvements in air quality as old diesel locomotives were being replaced by new electric trains.
Statistical analysis of the reduction in black carbon exposure achieved by the change predicted a reduction in excess cancer deaths by 51 per million people for passengers and 330 per million people for train conductors. EPA policy states that any exposure that increases the average individual’s cancer risk by more than one per million is considered unacceptable.
In the context of the whole U.S. where millions of people commute by rail every day, the study predicts that hundreds of cases of cancer could be prevented each year. California has long-term plans to electrify most of its rail systems. The study indicates that the process shouldn’t be carried over the next 25 years but rather be sped up.
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Electric trains are quieter, more reliable than diesel. New study finds they’re healthier, too.
Photo, posted September 4, 2024, courtesy of J. Kehoe via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio