Escalators might be an easier way to get between floors but one woman has made a gross discovery.

Many of us have been there. You're at the shopping centre, you're a bit tired so as you ascend you rest your hand on the rail of the escalator, just to lean a bit.

Insta / @samira_so

Everything is fine on the way up, but when you take your hand off there's a feeling of greasiness and just a general ick on your palm.

Wiping your hands on your trousers just isn't enough, so you have to head to the bathroom to wash your hands.

If you have ever had this feeling, then there is a good reason as one woman has shown.

In a video, she stands by a perfectly normal escalator in a shopping centre. She shows a perfectly clean wipe to the camera, before proceeding to hold it down on the moving escalator handrail.

When she brings it back up, you might imagine that the wipe is not as spotless as it had been mere moments before.

Instead it is covered by a great black stain from the contact with the handrail.

Gross.

To be fair, it's hardly surprising. You know how they lubricate the handrails on escalators? Palm oil.

I'll show myself out...

However, it's possible that the greasy mark may not actually be the accumulated gunk from thousands of hands over the years. It may be something applied to the escalator to help keep it running smoothly.

Insta / @samira_so

After all, if you have moving parts in a machine it really doesn't help if they get jammed up because of friction. That said, slapping a load of industrial lubricant onto something where people's hands go doesn't sound like the most hygienic idea either.

Grease is one thing, but one commenter had an interesting suggestion to see just how dirty the handrail is in a more biological sense.

They wrote: "She should have taken a culture swab to see what kinds of bacteria or fungi can grow. I remember in my microbio class we swabbed areas of the campus, and found that the buttons on a vending machine grew more samples than the floor of the mens restroom."

You've seen those videos, where a little Petri dish filled with things bacteria love to eat are swabbed. Perhaps unsurprisingly it's places which are frequently touched by people that produce the most colourful (literally) results.

With something like an escalator handrail who knows what bacteria might flourish on that Petri dish.

Get the UN on the phone!