Insects in the Fyris river carried 33 different pharmaceutical substances

18 March 2022

Fyris river, Uppsala

Fyris river, Uppsala

In a study of insects in the Fyris river, researchers identified traces of 33 different pharmaceutical substances. "In combination, these substances can give unexpected and amplified effects that, when they reach further up the food chain, might also affect us humans," says Emelie Sedvall, PhD student at Uppsala University.

Pharmaceutical drugs help us to longer and healthier lives, but via the wastewater, their active substances can reach the environment, and in a longer perspective put entire ecosystems in imbalance. In a recently published study of insects in the Fyris river, researchers at Uppsala University have identified traces of 33 different pharmaceutical substances, of which eight were found in more than eighty percent of the samples. The most common classes include antidepressant and antipsychotic drugs.

“We know from previous studies that the water in the Fyris river contains pharmaceutical substances. That they are also present in all five species of insects that we have studied is worrying, as many of these substances have similar effects in animals as in humans,” says Emelie Sedvall, PhD student at the Faculty of Pharmacy.

A majority of the substances identified by the researchers are prescribed by Region Uppsala. The highest measured concentrations contained tetracycline, an antibiotic that, due to overuse, is subject to the challenges that comes with resistant bacteria. Several insects were also found to carry antihistamines, a substance given to treat allergic reactions.

Emelie Sedvall, PhD student
Emelie Sedvall, PhD student

“Many of these substances can cause erratic behavior. For example, Fexofenadine, an antihistamine drug, has a calming effect on one of the species that we have studied, which may cause them to expose themselves to increased risks. In addition, these drugs can, when combined, give both unexpected and enhanced effects, and considering that these insects are on low levels in the food chain, there is considerable risk that we humans will also be affected,” says Emelie Sedvall.

An example of consequence when drugs transfer between species occurred when the number of White scavenger vultures decreased significantly in India during the 1990s. The reason was traced to the fact that the birds ate meat from dead cows that during their lifetime were medicated with diclofenac, an anti-inflammatory substance that destroyed the vultures' kidneys. Although diclofenac may no longer be given to cattle for preventive purposes, the release of active drug substances remain unregulated in large parts of the world. Likewise, much of the pharmaceutical drugs we consume and excrete run unaffected through the sewage plants.

“The impact that drugs have on our environment is without a doubt an acute challenge to society. We now need knowledge, tools and methods to steer in the right direction, and we are very positive to the fact that Uppsala University, within its involvement in the Medical Products Agency's Knowledge Center for Medicines in the Environment, has initiated a new course in the subject that will strengthen Sweden's capacities to handle the situation,” says Mikael Hedeland, Professor of Analytical Pharmaceutical Chemistry.

In the current study, the researchers used two different types of mass spectrometers. Starting with a simpler instrument, they determined whether the drug substances were present in each insect. In a second analysis with a mass spectrometer generating higher resolution, the researchers succeeded in extracting considerably more detailed information from the samples than was previously thought possible.

“The fact that the more advanced instrument showed useful in our research gives us the opportunity to map a completely new spectrum of pieces. We are already developing new and more effective methods to purify our samples. Once we succeed, we will generate even more precise knowledge about which drug substances that are taken up by aquatic insects, so that we in the future can determine what effects these will have on the environment, animals and possibly also humans, says Emelie Sedvall.


  • Traces of 33 different pharmaceutical substances have been identified in insects in the Fyris river.
  • The most common substances were antidepressants and antipsychotic drugs as well as antihistamines.
  • The concentrations in the insects amounted to 260 ng / g.
  • The researchers used UHPLC tandem quadrupole MS / MS and UHPLC-qToF-MS / MS.
  • The study was conducted in collaboration with researchers at Umeå University.

Last modified: 2021-02-14