Showers and baths are polluting water supplies partly due to growth in shampoos, gels and skin products, new research has said.
According to a report in the Telegraph, researchers have detected substances in water supplies that have come from prescription drugs and toiletries.
In the past, environmental concerns have focused on sewage as a source chemical pollution as it is thought antibiotics and the active ingredients of pills are flushed down the lavatory.
But now, the new research by the US Environment Protection Agency suggests that waste from showers and baths should also be looked at.
Dr Ilene Ruhoy, who coauthored the study reported at the American Chemical Society annual meeting, said that scientists have long known that bathrooms are a "portal" for release of so-called active pharmaceutical ingredients (APIs) into the environment.
An active ingredient in a pill is the medicine, usually combined with binders to hold the pill together, stabilisers, and other inactive ingredients.
However, scientists and pollution control officials had previously assumed that lavatories were the main culprit, with APIs excreted in urine and faeces and flushed into sewers and sewage treatment plants.
But now the new sources of the pollutants have been found.
Dr Ruhoy and her team identified this potential new source of APIs through a comprehensive review of hundreds of scientific studies.
"These routes may be important for certain APIs found in medications that are applied topically, which means to the skin," said Dr Ruhoy.
"They include creams, lotions, ointments, gels, and skin patches," she added.