Many commonly used pharmaceuticals are not completely metabolised by the human body. Instead they are passed on, via sewage treatment plants, to lakes and streams. Researchers have so far been able to identify traces of over 150 different pharmaceuticals in the environment. Yet, little is known about how these residues affect animals and plants.
‘The objective of my thesis is to gather data that can be used to improve environmental risk assessments of medicines and to develop methods that can help identify effects of drugs in the environment’, says Lina Gunnarsson, doctoral student at the Sahlgrenska Academy.
Pharmaceuticals are designed or selected to affect specific processes in the body. They do this by binding to certain target molecules, for example a receptor or an enzyme. Animals with target molecules that are similar to those in humans may therefore be affected by residues of human pharmaceuticals that are present in the environment.
‘Water fleas and algae are often used to assess environmental risks, but our research shows that the results from such studies should not be extrapolated to, for example, fish. Basing the assessment on species that are insensitive can lead to an underestimation of the actual risks to the environment. Fish and frogs have many more target molecules that are similar to those in humans, and we therefore suggest using more comprehensive tests in such species’, says Gunnarsson, whose study was recently awarded ‘the AstraZeneca Award for Best Publication in Risk Assessment, Modelling and Theoretical Studies’.