Drugs in water worry
20 Oct 2004
Once drugs have done their work in the body, they, or their residues, inevitably end up in the wastewater stream.
What happens to them there has not been subjected to much study. The US National Institute of Standards and Technology (NIST) has decided to rectify this situation - and has come up with some worrying results.
Drug residues in wastewater are subjected to chemical treatment at sewage works, including exposure to chlorine. The NIST team looked at four pharmaceuticals sometimes found in the environment, including antibiotics and painkillers.
The researchers found that the treatment tended to convert the drugs into more hydrophobic forms than their parent molecules. Hydrophobic substances tend to be bioaccumulative, although not necessarily harmful. However, one antibiotic, acetaminophen, formed multiple products when treated with chlorine, two of which are highly toxic.
The researchers used techniques such as liquid chromatography and mass spectrometry to characterise the reaction products. The data and techniques developed on the project will help other laboratories investigate the possible health or environmental effects of the substances.
