Switching from diesel to electric trains dramatically improved the air quality aboard the San Francisco Bay Area's Caltrain commuter rail line, reducing riders' exposure to the carcinogen black carbon by an average of 89%, finds a new study.
Switching from diesel to electric trains dramatically improved the air quality aboard the San Francisco Bay Area's Caltrain commuter rail line, reducing riders' exposure to the carcinogen black carbon by an average of 89%, finds a new study.
The electrification of the system also significantly reduced the ambient black carbon concentrations within and around the San Francisco station. Switching from diesel to electric trains dramatically improved the air quality aboard the San Francisco Bay Area's Caltrain commuter rail line, reducing riders' exposure to the carcinogen black carbon by an average of 89%, finds a new study published today in the journalThe electrification of the system also significantly reduced the ambient black carbon concentrations within and around the San Francisco station, the study found. "The transition from diesel to electric trains occurred over just a few weeks, and yet we saw the same drop in black carbon concentrations in the station as California cities achieved from 30 years of clean air regulations," said study senior author Joshua Apte, a professor of environmental engineering and environmental health at the University of California, Berkeley."It really adds to the case for electrifying the many other rail systems in the U.S. that still use old, poorly regulated diesel locomotives." Caltrain operates the busiest commuter rail system in the western U.S., carrying millions of passengers a year along its 47-mile route between San Francisco and San Jose. Over the course of six weeks in August and September 2024, the system retired all 29 of its diesel locomotives and replaced them with 23 new electric trains. The debut of the new trains was the culmination of a $2.44 billion modernization and decarbonization project that first launched in 2017. Apte, an expert in air quality monitoring, was inspired to pursue the study after visiting a Caltrain station in August 2024, when the very first electric trains were being introduced. "I was stunned at how much the station smelled like diesel smoke and how noisy it was from the racket of diesel locomotives idling away at the platforms, dumping smoke out into the community," Apte said."A light bulb went off my head -- I realized this would all be going away in a few weeks." After securing the support of Caltrain, Apte and study lead author Samuel Cliff quickly mobilized, installing black carbon detectors at Caltrain stations and carrying portable air quality detectors aboard the trains. For four weeks, they tracked the rapid improvements in air quality as old diesel locomotives were replaced by new electric trains. "A lot of these transitions happen pretty slowly. This one happened in a blink of an eye," Apte said."We had the unique opportunity to capture the ancillary public health benefits." According to Apte and Cliff's calculations, the reduction in black carbon exposure achieved from Caltrain's electrification cut excess cancer deaths by 51 per 1 million people for riders and 330 per 1 million people for train conductors. For reference, the U.S. Environmental Protection Agency has a policy that any exposure that increases the average individual's cancer risk by more than one per million is considered unacceptable. "If you think about this in the context of the whole of the U.S., where we have millions of people commuting by rail every day, that's hundreds of cases of cancer that could be prevented each year," said Cliff, a postdoctoral scholar at UC Berkeley. The majority of U.S. commuter trains are still powered by diesel fuel, despite the fact that electric trains are quieter, more reliable and produce fewer greenhouse gases than diesel locomotives. Apte hopes the study motivates more U.S. municipalities to follow the lead of Asian and European countries in electrifying their railways. "This is something that we ought to find a way to do as quickly as possible, everywhere," Apte said."California has long-term plans to electrify most of its rail systems, but this shows that we shouldn't be waiting another 25 years to get it done. We should be speeding it up."The first health impact study of coal train pollution centers on the San Francisco Bay Area, with scientists finding communities near passing coal trains suffer worse health ... Black carbon is up to 25 times more hazardous to human health than other airborne particles of a similar size. Standard sensors are expensive and burdensome, resulting in sparse coverage in regions ... A new study found overlooked tsunami hazards related to undersea, near-shore strike-slip faults, especially for coastal cities adjacent to faults that traverse inland bays. Several areas around the ... When the San Francisco Bay Area mandated shelter-in-place March 16, it created a natural experiment for UC Berkeley's Ron Cohen, who had established an inexpensive pollution sensor network in local ...Sunscreen, Clothes and Caves May Have Helped Homo Sapiens Survive 41,000 Years Ago
Petroleum Electricity Air Quality Air Pollution Environmental Science Transportation Issues Environmental Policies Travel And Recreation
United States Latest News, United States Headlines
Similar News:You can also read news stories similar to this one that we have collected from other news sources.
Man who escaped homelessness shares story in new film on San Francisco housing crisisCarlos Rojas is learning to appreciate the simple things in life. After three years of living on the streets of San Francisco, he now sees basic shelter and safety as true luxuries.
Read more »
San Francisco Pride takes financial hit after major companies pull sponsorships amid DEI falloutSan Francisco Pride org takes financial hit due to several companies pulling funding amid the trend of businesses pulling back on DEI initiatives.
Read more »
San Francisco Is Getting Its Own Council of Tech OligarchsMore than usual, San Francisco's C-suite will now have access to city hall.
Read more »
Residents report worsening homelessness and drug activity on San Francisco streetsResidents who live near San Francisco’s Potrero Avenue are expressing frustration as homelessness and drug activity worsen. Many describe the situation as a 'whack-a-mole' problem, with individuals being moved from block to block without lasting solutions.
Read more »
Waymo poised to expand robotaxi service to San Francisco International Airport, additional South Bay areasAutonomous vehicle firm Waymo is in the process of expanding the locations it serves around the Bay Area.
Read more »
San Francisco Giants Affiliate to Relocate After Stadium Battle Hits Fever PitchThe Eugene Emeralds, who have called Eugene home for 70 years, are set to move in the coming years.
Read more »