Many European rivers and canals are contaminated with pesticides, according to a new analysis slated for publication on 20 June in Science of the Total Environment, a peer-reviewed journal (1). More than 100 pesticides, several of which are currently banned in the EU, were detected in samples from waterways of 10 European countries.
The researchers from the Greenpeace Research Laboratories, based at the University of Exeter, screened water samples from 29 small waterways located in 10 different countries in the EU, including Austria, Belgium, Germany, Denmark, France, Italy, the Netherlands, Poland, Spain, and the UK. They tested for 275 pesticides and 101 different veterinary drugs.
The extent of pesticide contamination in European waterways
Pesticides reach waterways via spray drift and are also leached from plants and soil after being applied and make their way to nearby rivers and streams. The researchers discovered pesticide contamination in all rivers and canals examined in the study. Of the 103 pesticides detected, 24 are currently banned in the EU. In addition, around 50 per cent were herbicides. The other half comprised of fungicides or insecticides.
The banned pesticides detected by the researchers were not necessarily used illegally, as they point out. But may have been used before a ban was put in place or for purposes that allow their use. However, they do mention the “remarkable” concentrations and frequency of carbendazim. The broad-spectrum fungicide is banned in the EU but was present in 93 per cent of water samples.
Several veterinary drugs ― 21 in total, mainly antibiotics ― were detected in most waterways. Often, antibiotics are not fully absorbed in the gastrointestinal tract of animals. This enables them to be dispersed into the environment, including waterways, through animal excrement and by spreading contaminated manure on fields.
Troubling impact of pesticides on smaller waterways
Pesticides from agricultural land use are contaminating Europe’s rivers and posing a serious threat to freshwater biodiversity. Ultimately, this could compromise entire river ecosystems, the authors write.
This is particularly troublesome for river ecosystems in agricultural catchment areas. Small rivers and streams that weave through the surrounding agriculture landscapes are at a higher risk of pesticide contamination. Furthermore, increased exposure to pesticides may have an even bigger impact on freshwater biodiversity. Particularly, since agrochemicals and drugs are less diluted in small rivers compared to larger bodies of water.
Some individual pesticides alone are cause for immediate concern. Not to mention, exposure to an array of harmful agrochemicals could have serious implications for wildlife and human health. Moreover, pesticides and antibiotics are likely making their way into drinking water.
The need for sustainable farming practices to reduce pesticide use
The problem can only be solved by moving away from the current reliance on pesticides and antibiotics. And will only be achieved by taking advantage of precision agriculture and plant breeding technologies to ensure global food security while optimising agricultural practices and reducing the need for pesticides.
The findings highlight a critical need for a concerted effort among farmers, policymakers, and other organisations towards sustainable farming practices.
(1) Casado, J. et al. Screening of pesticides and veterinary drugs in small streams in the European Union by liquid chromatography high resolution mass spectrometry. Science of The Total Environment (2019) DOI: 10.1016/j.scitotenv.2019.03.207