Research found the dust was toxic and able to enter the bloodstream via the nose
(Picture: AP)Tube dust has the potential to cause serious illness in passengers and station staff, landmark research has revealed.
The first study on the impact of PM (particulate matter) particles from an underground railway found exposure increased the risk of pneumococcal infections such as pneumonia.
Professor Jonathan Grigg, who led the Queen Mary University of London research team, said concerned commuters should try to switch from deep-level to sub-surface lines or the Elizabeth line, which has advanced air ventillation systems.
He suggested that Transport for London publish a “clean line index” of Underground lines. He called for a study of Tube staff that compared the health of drivers and platform staff with those working closer to the surface.
Previous studies found levels of microscopic PM10 and PM2.5 were more concentrated on the Underground compared with above ground, but had been unable to assess the health implications.
The QMUL study, published in The Lancet, found the dust — mainly iron and graphite particles — was toxic and able to enter the bloodstream via the nose, a process called “pneumococcal adhesion and penetration”.
Professor Grigg, the UK’s leading paediatrician on the effects of air pollution in children, told the Standard: “I think the bottom line is that Tube dust, at least in the deep Underground lines, which is generated by the trains and the tracks, is not just ‘nuisance dust’ you can ignore.”
Researchers collected dust from the Bakerloo and Jubilee line platforms at Baker Street station. The dust was mixed with saline and transferred onto the noses of laboratory research mice.
This resulted in the “remarkable finding” that exposure to the dust increased mortality from pneumococcal infection and the ability of bacteria to enter the body. Laboratory tests were also done using human cells, which confirmed the ability of the dust to harm humans.
However, it is unknown how frequently commuters are at risk of being exposed to the levels of pollutants underground that could cause harm.
Professor Grigg said: “Normally bacteria just hang around for a little bit in the nose and don’t cause any disease. With the mice that we penetrated with the dust, some got very severe disease.”
TfL regularly monitors dust. In December, the results from 12 stations found concentrations had increased at four — Baker Street, Aldgate East, Elephant & Castle and Waterloo.
Lilli Matson, TfL’s chief safety, health & environment officer, said: “Our monitoring has shown that dust levels on the Tube remain well below limits set by the Health and Safety Executive, but we are going further and have developed a number of innovative new cleaning regimes.
“This includes the use of industrial backpack dust cleaners, which are one part of our multi-million pound Tube cleaning programme.
“We are working closely with Queen Mary University London to review the results of their study, in addition to working with other leading academics such as Imperial College London, to ensure we fully understand any possible health risks associated with dust on the Tube.”
