What is this???!!!!! (Photo attached)

[WhatIsThisPlease]

I've just started painting my bathroom ceiling and decided to give the tiles a quick wipe first.

The cloth was black!! Like literally black

It's only the top two rows of tiles, the rest are fine? They didn't even look dirty until I started wiping.

Is it dirt or mould? It looks like soot - like you get from candles (but I don't light candles in there).

Eurgh.

Mould

What does it smell like?

Looks like mould

I'd guess mould.

Do you have black/dark grout?

If you live in London, leave the bathroom window open, and tend to only clean the tiles up as high as you can reach which, coincidentally is two tiles down from the ceiling, then what you are looking at there is grime. I would know because I only get up to the top row of tiles about every 10 years .

Could be from car exhausts if you live in town. I used to live on a busy road that was a bus route. Black dust constantly getting into the house.

Do you light candles in your bathroom? I have ruined wallpaper with soot near where I light candles. Just a thought.

It's damp/mould caused by inadequate ventilation. We get it in our bathroom and waiting for the landlord to fit an extractor.

Another vote for grime caused by pollution. If it was mould you'd be able to see it before you wiped. In areas with poor air quality grime just slowly coats surfaces that aren't wiped properly like bathroom tiles that are too high to reach.

Don't think it's pollution, I live in a small village at the end of a cup-de-sac so not much traffic.

It doesn't smell and you definitely couldn't see it before I wiped it. I never light candles in there.

I think as PPs have said it must be mould. It is a cold dark room so probably does get quite a bit of condensation, even though I shower with the door open.

Gross!! Will wipe more often from now on!!

There are anti mould sprays that you can buy