Putting A Lid On The Spread Of Infection

The common phrase "put a lid on it" can apply to stopping something or setting a limit to it.  For example, putting a lid on spending means the same as a cap on spending.  More generally, the phrase is a request to cease and desist, applied to behaviour such as persistent complaining or playing loud music.

How do you put a lid on the spread of infection?  The answer is simple, effective and quite literal: put a lid on it.

Back in the 1950s I was taught as a small child to wash my hands after using the toilet. Or bathroom if you prefer.  It seems that most people know to do that.  I was also taught to close the lid before flushing.  Not many people seem to have been taught that basic bit of hygiene.

What difference does it make?

Water under pressure doesn't behave like water being poured.  Have you never splashed yourself when using a garden hose?  Water spray certainly gets around.  The flushing toilet is no exception.  When you flush you create an aerosol.  It is a germ-laden aerosol.  Simply closing the lid before flushing dramatically reduces the spread of germs in the bathroom.

The spread of germs through such aerosols was investigated by Charles P. Gerba, Craig Wallis, and Joseph L. Melnick.  There findings were published in Applied Microbiology in August 1975.  I am astounded that this matter seems not to have reached a very wide audience.

The paper Microbiological Hazards of Household Toilets: Droplet Production and the Fate of Residual Organisms provides clear and unequivocal evidence that flushing a toilet can spread diseases.

So there you have it.  If you want to do your bit to help stop the spread of diseases: put a lid on it!

Reference:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC187159/

Credit:
I was reminded of the aerosol problem when I read 'Poop' dermatitis linked to fashionable toilet seats, harsh chemicals.  Thanks to science codex