Are you sitting on the Tube or the toilet? It might be difficult to tell the difference.

Research has lifted the lid on how filthy London Underground can be, revealing the dirtiest lines and stations along with the most germ-ridden surfaces that you might want to avoid touching.

Dozens of samples were taken at the busiest places on the network and the swabs were then tested at an independent laboratory.

Results were based on the (sciency bit) bacteria levels measured by counting the colony-forming units (CFU) – the number of viable bacteria cells – thriving in every 10 centimetres.

And some of those results were pretty disgusting.

Germs by line

The Northern line was found to be the most bacteria-laden, with more than 1,600 CFU/10 sq cm.

Your Local Guardian:

It was nearly three times germier than the Central line in second place, almost 15 times worse than Waterloo & City and a 91.5 times yuckier than Hammersmith & City where samples contained scant bacteria at only 18 CFU/10 sq cm.

Germs by station

The 10 busiest Tube stations based on official exit and entry figures were tested.

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Stratford contained the highest bacteria levels - teeming with 1,220 CFU/10 sq cm – more than twice as many germs as any other stop. Second germiest was Bank & Monument then Victoria.

Canary Wharf averaged the fewest germs followed by Liverpool Street and London Bridge.

The dirtiest spots

Various surfaces tested including handrails, ticket machines, ticket barriers, seats and poles were found to harbour several times more bacteria than toilet seats, toilet handles, and washroom light switches.

Your Local Guardian:

Generally, ticket machines were found to be the grimiest surfaces followed by vertical poles and ticket barriers.

A touchscreen ticket machine at Stratford had 10 times more bacteria than a toilet seat (2,560 CFU compared to 266) while a vertical pole on the Northern line was 18 times germier than a loo.

Gross, eh?

Your Local Guardian:

Staying healthy

Top hygiene tip for avoiding the possible ill-effects of touching these filthy surfaces is to frequently wash your hands with soap and warm water.

Carrying alcohol hand gel to use after your journey can also help prevent the spread of some infections.

Try to avoid touching your hands to your face while travelling on the Tube, cover your mouth and nose with a tissue if you cough or sneeze, save snacks and meals for after the journey and wash up as soon as possible once you arrive at your destination.

According to NHS Choices, you can help curtail the spread of illness through other simple steps, including avoiding unnecessary contact (including Tube travel) if you’re ill and getting an annual flu jab if you’re at risk. You can also reduce the spread of germs at home by removing your shoes before you enter and cleaning clothing and handbags that may have picked up bacteria.

Research data, information and images from DrEd.com