It sounds like the wisdom of a germaphobe, but it’s one of the findings in a new global review, published in Science of the Total Environment. The review determined that leaving the loo lid open after flushing might disperse contaminated droplets up to 1.5 metres, and these particles could hang around for up to 30 minutes.

Another review, published in Frontiers in Built Environment, found that the number of particles expelled by a toilet flush is equivalent to a person talking loudly for just over six-and-a-half minutes – the true definition of a potty mouth.

But the team found no evidence of airborne coronavirus transmission in public toilets.