New tracing method to determine plastic particle transport in agricultural soils
More than 320 million tonnes of plastic are produced worldwide every year. 25 per cent of this production – more than 80 million tonnes – ends up in our natural environment, where it persists over decades or even centuries. By using a new plastic particle tracing method, researchers at the University of Gothenburg aim to find out how plastic particles in agricultural soil are transported to groundwater systems.
– A large portion of the environmentally released plastic accumulates in agricultural soils due to the application of sewage sludges as fertilizer, the use of compost, the application of plastic mulching and packaging, says Philipp Wanner, Assistant Professor and Head of the Contaminant Hydrogeology Research Group at the University of Gothenburg.
Together with researcher Ramin Moghadasi, he is conducting a research project on the combination of plastics and pesticides in agricultural soils and the consequences for groundwater systems and drinking water supply.
– Of concern is the fragmentation of plastics in agricultural soils to hardly detectable and mobile micro- and nanosized plastic particles. These can potentially migrate into underlying groundwater systems and drinking water supplies, says Ramin Moghadasi, Postdoctoral Researcher in the Contaminant Hydrogeology Research Group at the University of Gothenburg.
A new plastic particle tracer method will help the researchers to find out how plastic particles in agricultural soils are transported to groundwater systems and pose a risk for groundwater quality. The novel tracer method will be based on the labelling of the plastic particles with heavy carbon isotopes (13C).
Co-occurrence of plastic and pesticides
In addition to plastic particles, large quantities of pesticides are applied to agricultural soils - as much as 4.5 million tonnes per year - leading to a co-occurrence of plastic and pesticides.
– When plastic particles and pesticides are present in agricultural soil at the same time, we can expect plastic-pesticide interaction, which can potentially enhance the transport of pesticides into groundwater systems, says Philipp Wanner.
Previous research has been done on plastic-pesticides interactions at the soil surface. However, little is known about how this may affect the transport of pesticides into groundwater and drinking water supplies. By tracking the transportation path as well as the interaction with pesticides, it will be possible for the first time to assess the risks for groundwater systems, drinking water supplies - and eventually to human health.
– We hope that the result of this research will be the basis for better regulations in the future regarding the general use of plastics and pesticides in the agricultural process and for the protection of groundwater systems, says Ramin Moghadasi.
For further information, please contact:
Philipp Wanner, philipp.wanner@gu.se, Assistant Professor, Department of Earth Sciences, University of Gothenburg
Ramin Moghadasi, ramin.moghadasi@gu.se , Postdoctoral Researcher, Department of Earth Sciences, University of Gothenburg
BY: JENNY MEYER
The project "Plastic and pesticides in agricultural soils – A hazardous combination for groundwater systems and drinking water supplies worldwide?“ is funded by the Starting Grant from the Swedish Research Council (VR) awarded to Dr. Philipp Wanner. The project runs until 2025.