Authors: Venla Forsell, Vili Saartama, Raisa Turja, Jari Haimi, Salla Selonen
Plastic contamination in agricultural soils is a growing concern, calling for a very careful management of plastic mulching films to avoid microplastics pollution. The latest study by Forsell et al. investigates the impact of microplastics from conventional polyethylene (PE) and biodegradable PBAT mulching films on the earthworms Eisenia andrei, which significantly contribute to soil-based ecosystem services, and are often termed as ‘ecosystem engineers’.
Results of the study reveal that both types of microplastics affect earthworm health and soil properties, but in distinct ways.
First, in terms of growth, PE microplastics led to a decrease in earthworm biomass at higher concentrations, while PBAT microplastics promoted growth at lower concentrations.
Second, both PE and PBAT microplastics triggered significant oxidative stress responses, with specific biomarkers (CAT, GR for PE; SOD, LPO for PBAT) being particularly affected.
Finally, concerning microplastics impact on soil, at higher concentrations, both types increased soil pH and water-holding capacity, potentially altering soil chemistry and contributing to the observed effects on earthworms.
These findings underscore the complexity of microplastics interactions in soil ecosystems, highlighting the need for ongoing research to fully understand the ecological risks posed by microplastics pollution.
Keywords: Agricultural soil; Biodegradable plastic; LDPE; PBAT; Environmental stress; Soil ecotoxicology
Published in: Science of The Total Environment, Volume 948, 20 October 2024, 174667
Read the full study here: https://www.sciencedirect.com/science/article/pii/S0048969724048162?via%3Dihub