Scientists from the University of Cambridge have discovered that the air of the London Underground contains a large number of small metal particles that can pose a danger to humans. The research was published in the journal scientific reports.
The study examined iron oxide nanoparticles ranging in size from 5 to 500 nm. They are formed during the operation of the brake pads of the train, as well as during the friction of the wheels on the rails. Because of their small size (smaller than a red blood cell), they can easily enter the bloodstream of subway passengers.
Scientists collected dust samples from air filters in ticket offices and train driver cabins on the main London Underground lines. For the analysis, they used a new method that allows you to identify the smallest particles.
Data on the danger these particles pose to human health remain controversial. But previous studies have linked them to an increased risk of Alzheimer’s disease and bacterial infections.
A 2021 study found high levels of pollution in US subways. Scientists believe that magnetic traps and more efficient ventilation can protect people from the harmful effects of iron oxide particles. And now, subway passengers can probably limit their direct exposure to subway particles with regular face masks.