Take a cold shower

The suggestion made by two University of East Anglia students that urinating while showering could result in huge water savings (“The week in higher education”, News, 16 October) may have health consequences that were not foreseen by the authors of this scheme.

Our water is chlorinated, and chlorine reacts with organic matter in the water to form “disinfection by-products” (DBPs). Those formed in the presence of urine include nitrosamines – a particularly toxic group of compounds. When one stands under a hot shower for a long period of time, one is in effect standing in a cloud of volatile DBPs and breathing them in. Exposure to DBPs can lead to increased incidences of certain types of cancer – cancer of the bladder in particular.

My tip for saving water, energy and the planet is quite simple: short cold showers. Pee in the toilet but don’t necessarily flush after each emptying of the bladder.

Dr Gilbert Shama
Reader in applied microbiology
Loughborough University