Microplastics in the soil act as a "Trojan horse" for transporting toxins

A large-scale EU-funded study covered 227 agricultural fields across 11 European countries, and microplastic particles were found in all of them. The contamination is linked both to current farming practices and past land use, while the presence of plastic itself persists for many years. In Swiss farms, it was found that plots with the highest amounts of tire wear particles also contain the highest concentrations of other metals and toxic chemicals.

Researchers established that a so-called "plastisphere" forms on the surface of microplastics, serving as a favorable environment for the interaction of microbes, agrochemicals, and plastics. An increase in the number of antibiotic resistance genes has been recorded in such zones, with pesticides intensifying this process. As Edoardo Puglisi from the Università Cattolica del Sacro Cuore in Piacenza (Italy) explained, a reduction in the size of microplastics enhances its ability to adsorb DNA, microbes, and pollutants. A "Trojan horse effect" arises, facilitating the spread of pathogens and antibiotic resistance.

Such impacts disrupt key vital processes of soil organisms and earthworms, which are important for the formation of the microbiome and ecosystem functions of the soil. The Minagris project, together with researchers from the University of Gloucestershire, also documented the impact of microplastics on plant development. Using lettuce as an example, it was shown that high concentrations of particles reduce leaf area, chlorophyll content, photosynthetic efficiency, and biomass. Under drought conditions, the negative effect was intensified.

The project authors note that biodegradable plastic is not automatically safe, since upon degradation it also turns into microplastics and causes ecological harm. According to Esperanza Huerta Lwanga from Wageningen University (Netherlands), plastic fragmented in the soil is virtually impossible to remove, acting as a vector for agrochemicals. Experts emphasize the need for standardized monitoring, transparency from manufacturers, and risk assessment of the interaction of microplastics with associated pollutants to protect soil health and long-term food production.