Water used externally can be even more hazardous than water you drink. Showers and to, a lesser extent, baths lead to a greater exposure to toxic chemicals contained in water supplies. The chemicals evaporate out of the water and can be inhaled .

Researchers at the University of Pittsburgh measured the volatility of two chemicals commonly found in water supplies: trichlorethylene (TCE) and chloroform. The former is a pollutant found in ground water and the latter a by product produced when chlorine is used to disinfect water.Sprayed through a nozzle, 50 per cent of the chloroform and 80 per cent of the TCE vaporizes. A bath produces only half as much vapour due to the greater total surface area of the shower droplets. The longer and hotter the shower, the more the chemicals build up in the air; levels are four times greater after a 10 minute shower than a five minute one. The Pitssburgh researchers estimated that people in houses would receive from six to 100 times more of the chemicals by breathing the air around showers, baths, dishwashers and washing machines than they would by drinking the water.

Studies from the United States Environmental Protection Agency and the National Academy of Science have attributed between 200 and 1000 cancer deaths each year in the United States to ingesting chloroform in drinking water.

If you can bear it, take a quick cold shower having first vigorously brushed your skin all over with a natural bristle brush. Otherwise, shut the bathroom door and keep the windows open while hot showering. Keep it brief and finish off with a cool rinse.