Tests find 34 pesticides and antimicrobial drugs in Devon rivers

The pesticides included eight that are not approved by the EU (Photo: River Culm, Derek Harper)
The pesticides included eight that are not approved by the EU (Photo: River Culm, Derek Harper)

Tests on four rivers in Devon have revealed high contamination levels which included 34 pesticides, as well as 9 antimicrobials and veterinary drugs

Scientists from the University of Exeter said they were "surprised and concerned" by the results, and warned there would be harmful effects for plants and wildlife.

The water samples were taken in rural areas from the rivers Culm, Exe, Otter and Tale.

The highest single concentration was of a pesticide called MCPA, recorded at more than 130 nanograms per litre of water.

The pesticides included eight that are not approved by the EU – although the researchers say these could have come from residues from historic uses, and some could have been by-products of other pesticides.

Five of the pesticides found – atrazine, carbendazim, diuron, griseofulvin and imidacloprid – were present in all the samples taken from the rivers.

The tests were carried out using a new technique at Greenpeace Research Laboratories at the university,

“We were surprised by both the number and concentrations of pesticides we found,” said lead researcher, Jorge Casado.

“The level of each individual pesticide was below EU legal limits, but those rules don’t take account of mixtures. Little research has been done on the effects of combinations of pesticides.

“The findings are certainly a concern and, although it’s hard to be sure of the impacts of mixtures of pesticides, there will certainly be effects on wildlife and plants in and around these rivers.

Mr Casado added: “Our study demonstrates an environmental problem not just in Devon but in any region affected by commercial agriculture.”