On February 9, a Norfolk Southern train derailed near East Palestine, Ohio, spilling 11 cars’ worth of hazardous materials into the ground. While no one was injured in the accident, government officials evacuated the town so that firefighters could perform a controlled explosion of some of the containers carrying a toxic chemical called vinyl chloride, which is used to manufacture PVC.
This caused an apocalyptic plume of black smoke to rise above the area, and has led to concerns about air and water pollution by local residents, some of whom have complained of headaches and nausea after being cleared to return to their homes.
Train accidents in the U.S. are unfortunately common: In the first two months of 2023, the government has already recorded more than a dozen derailments. Each year, more than a thousand trains go off track.
And while fiery crashes with towering smoke clouds make for lots of headlines, studies suggest trains carry health costs even when they don’t derail.
Noise pollution and vibrations are some of the biggest concerns, particularly for people who live within one-third of a mile of railroads or railyards, says Natalia Caldeira Loss Vincens, an expert in public health at the University of Gothenburg in Sweden. (Learn more about the effects of noise pollution on people and wildlife.)
“The whole idea is that these exposures to noise and other things, they are stressful,” says Vincens. Heightened levels of cortisol, a type of stress hormone, can lead to various health problems.
For instance, in a 2022 study in the journal Environmental Research, Vincens found a link between railway noise and incidences of diabetes, even when accounting for variables such as sociodemographic and lifestyle factors.
Chronic stress can lead to “a cascade of pathophysiological changes,” says Vincens, including things like alterations to a person’s insulin sensitivity, inflammation, and changes in appetite.
The sound and the fury
Though railcars can be extremely loud, “if the sounds are quite stable, in the end, we do not perceive it at all,” says Luca Fredianelli, an acoustic technician with the Italian National Council of Research.
It’s the less intense but more unpredictable noises, such as squeals, whistles, and grinding brakes, that really bother people, since they’re difficult to acclimate to, he says.
Such “unconventional noises,” as he calls them, are also much more difficult to quantify and link directly to health effects, he admits.
But it’s likely that such low-level noises can contribute to difficulties with mental health, cognition, and sleep.
For instance, in laboratory sleep studies, people exposed to vibrations like those emanating from rail traffic have fragmented sleep cycles, revealed by changes in heart rate, Vincens says. (Learn more about the secrets of sleep.)
“What we think is that if you keep having these effects over and over, if you live close to this railway, then it might lead to chronic changes in how your physiology works,” says Vincens.
“But these are still theories,” she says. It’s also challenging to prove causation, for example that railway noise causes diabetes. But scientists are assembling more and more data pointing to the many different health risks of noise exposure.
Something in the air
Trains are generally thought to be a green alternative to fossil fuel-heavy modes of transportation, such as cars and airplanes, but many types still burn diesel fuel. And those emissions can build up, particularly in enclosed areas. (Watch how people are trying to break their fossil fuel habit.)
One study at the U.K.’s London Paddington Railway Station found that its trains contributed to nitrogen dioxide emissions that exceeded the European Union’s limits for outdoor air quality. And those levels remained high on the street, where measurements of particulate matter, sulphur dioxide, and nitrogen dioxide were all elevated.
Railyards—places for storing and repairing rail vehicles—add another layer of community risk, because of the concentration of diesel-burning vehicles, including trucks, cranes, switch locomotives, and line-haul locomotives.
In one study conducted at the BNSF Railway Hobart Railyard in Los Angeles, the California Environmental Protection Agency estimated that residents living near a railyard experienced a higher risk of carcinogen exposure. That means increased cancer risk rose between a hundred and 3,000 times compared with surrounding areas.
Railway benefits to health
While the evidence mounts that living near rails has myriad impacts on human health, it should also be noted that proximity to certain kinds of trains also has benefits.
Jennifer D. Roberts, an associate professor in the School of Public Health at the University of Maryland, says access to light-rail systems in urban areas can benefit us.
“Research has shown over and over that people who live near light-rail trains have had an increase in their physical activity, significantly, and have had a reduction in excess weight,” says Roberts.
That’s because rail systems often require people to walk up to a mile or more to get to a train stop. They also connect underprivileged communities to areas they might not have had access to before, says Roberts. (Read why exercise keeps the brain healthy.)
In the end, Roberts says there are pros and cons, but that any rail line—be it freight or passenger, heavy or light—will always have environmental justice considerations that need to be investigated thoroughly.
“We need to look critically at these issues,” says Roberts. “They should be a burden that we all take up, and not just certain communities.”