By David Derbyshire
Traces of potentially dangerous medicines may be contaminating tap water and putting unborn babies at risk, scientists have warned.
There are growing concerns that powerful and toxic anti-cancer drugs are passing unharmed through sewage works and finding their way back into the water supply.
The Government is taking the threat so seriously it has asked scientists to start testing untreated river water at the point it is abstracted for human consumption.
Tap water contains minute traces of pharmeceutical drugs used to treat cancer that could be fatal to a foetus
a mixture of drugs could be harmful to foetuses.
Experts will meet in the next few weeks to decide which five drugs to test for
Doctors are most concerned about ‘cytotoxic’, or cell-killing, cancer drugs.
The trials will also test for anti-inflammatory drugs, sedatives and at least one illegal drug such as cocaine or heroin.
Under the existing rules, tap water is monitored for nearly 50 contaminants by the inspectorate – including lead, arsenic, mercury and cyanide.
However, no tests are carried out for pharmaceutical drugs.
Earlier this year, a theoretical study by the Centre for Ecology and Hydrology at Wallingford, Oxfordshire, concluded that there could be sufficient levels of one of the most common anti-cancer drugs – 5-fluorouracil, known as 5FU – to contaminate tap water.
Dr Andrew Johnson, a water quality scientist who led the study, found that the drug would be present in concentrations of up to 50 billionths of a gram in one litre of water.
Although that dose is low, river water could contain similar low doses of 30 or 40 other anti-cancer drugs.
‘The mode of action of these drugs is to stop cells dividing,’ he said.
The biggest concern was the female sex hormone oestrogen used in the Pill and in hormone replacement treatment. Oestrogens from sewage works have been shown to alter the sex of river fish.