A Closer Look at the Germs That Call London Underground Home

By Gary Cutlack on at

We have another one of those London Underground map reworking stories today, with this one assembled to show the tube lines that feature the highest concentrations of bacteria.

Assembled by internet medical adviser Dr Edd, the Mind the Germs map charts the lab results of bacteria swabs taken from 60 surfaces inside the 10 busiest lines on the network. The results will astound you, or may at least have you pulling your jumper over your hand when pressing a door open button that's previously been mashed by thousands of unclean plague bearers.

To understand the data and have it terrify you, there's a measurement to know about. The results are charted in CFU/10 sq cm, with the CFU bit standing for colony-forming unit – a standard used to count active cells within a sample that can live and grow and therefore stand a chance of infecting people. Hence this chart of shame:


Dr Ed explains that a concentration of 1,647 CFU/10 sq cm makes the Northern Line the winner at having bacteria and therefore the loser at being a clean place for humans to be transported around in, with the north/south artery containing an amazing 91.5 times more germs than the equivalent hand rails and posts of the Hammersmith & City line.

The actual stations checked tell a different story. Stratford, on the Jubilee, Central and DLR lines, came out as the most disease-ridden spot by far, despite only being the seventh busiest station in the city. The cleanest one was Canary Wharf, a glass and concrete underground chamber where clearly nothing can exist.

So what can you do to adjust your standing/leaning/touching strategy to ensure you make it through a commute uninfected? The germ doctors suggest you might want to practise your balancing skills by not holding onto the handrails, as these, in particular the dirtiest ones at Bank & Monument and Oxford Circus stations, are where germs congregate, due to being endlessly touched by horrible other people who probably did a poo right before leaving home.

Stratford loses again outside of the trains, managing to have the dirtiest ticket machine touchscreens and barriers; another great advertisement for going contactless when travelling in the city. The Central line had the dirtiest seats, so pretend to be a gentleman and avoid those, with the Northern line featuring the most diseased vertical hand poles. So maybe just lean against those. If you're stopping other people from holding them it's actually for their own good.


That makes it pretty clear that it's not all a bit of scaremongering. How on earth can a ticket machine have ten times the number of germs on it as a toilet seat? Probably because the machine doesn't get bleached down by mum once a week and our hands are actually dirtier than our bottoms.

The advice offered makes travelling by tube sound like some sort of modern death pit horror, suggesting: "During your Tube journey, try to avoid absentmindedly touching your hands to your face, cover your mouth and nose with a tissue if you cough or sneeze, save your snacks and meals for after the journey, and wash up as soon as possible once you arrive at your final destination."

The one bit of good news to come from the swabbing of London's tunnels is that no coliforms or E. coli were detected, which is handy as the former tends to be found in human poo and spreads the worst diseases. So at least people seem to have got the message about washing their hands after going to the toilet.

And there's no need to worry too much about infections anyway. The London School of Hygiene and Tropical Medicine said that people who travel on public transport in the capital are actually marginally less likely to catch flu at least, with the school's infectious disease specialist Dr Adler saying in 2013 that: "In London where most people take public transport, the level of infection was no higher than elsewhere and in fact was slightly lower. Flu tends to be spread by direct contact and so it is probably children who are tending to drive the spread more than public transport."

So no need for the surgical mask, not unless you're heading off to a cosplay event as a sexy zombie nurse. Just remember that when in stations, as in life itself, it's best to keep your hands to yourself. [Dr Ed via Metro]

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