By Richard Gray
Britain’s tap water should be monitored for powerful medicines after traces of cancer and psychiatric drugs were detected in samples, a report has warned.
The 100-page statement, commissioned by the drinking water watchdog, the Drinking Water Inspectorate (DWI), reveals that pharmaceuticals are finding their way into the water supply despite extensive purification treatments used by water companies.
Trace levels of bleomycin, a cancer chemotherapy drug, and diazepam, a sedative, have been found during tests on drinking water, the report reveals.
While the levels are considered too low to pose a direct risk to health, doctors have expressed concern about exposing pregnant women to drugs that could harm an unborn child.
The report, compiled for the DWI by the consultants Watts and Crane Associates, recommends that drinking water should be monitored for hazardous drugs.
The report states: “The observed concentrations of pharmaceuticals in raw waste water indicate that the major source of pharmaceuticals to the environment is via sewage treatment works effluent.
“Drinking water treatment works use a wider and technically more advanced range of processes, but again these are not specifically designed to remove pharmaceuticals and several compounds have been reported in drinking water.”
But it adds: “Even in the worst-case situation, there is no significant risk to health from the intake of pharmaceuticals via drinking water.”
Sue Pennison, from the DWI, said: “The recommendations are now being considered and this may include conducting testing on drinking water.”
The report comes as a separate study by environmental scientists has warned that toxic chemotherapy drugs used to treat cancer patients are being washed into Britain’s rivers. They, too, have called for testing of tap water to ensure there is no risk to people.
The study, carried out at the Centre for Ecology and Hydrology in Wallingford, Oxfordshire, examined the risks posed by chemotherapy drugs that escape into the environment through sewage.
The researchers estimated that an adult drinking more than three pints of water a day would receive a weekly dose of between 300 and 30,000 times lower than recommended safety levels.
They warn that a developing foetus would also be exposed to the drugs in the womb.
Andrew Johnson, the scientist who led the Wallingford study, said: “In the foetus, which is rapidly growing and comparatively tiny, the dose would be relatively higher and any damage to its cells could be far more serious.
“There is not evidence to show that drinking water treatment removes all these drugs, so while we are not wanting to alarm people, it would be foolish to assume there is no risk.”