Microplastics and nanoplastics barely enhance contaminant mobility in agricultural soils

Farmland soils are increasingly contaminated with micro- and nanoplastics (MNP) from various agricultural practices. Concerns exist that MNP act as vectors for organic contaminants, transporting them to deeper soil layers and potentially endangering groundwater. This study investigates the extent to which MNP facilitate organic contaminant transport using diffusion models. The analysis suggests that contaminant desorption is typically too fast for MNP to significantly enhance transport, except for very hydrophobic contaminants (logKow >5) under preferential flow conditions. While MNP may be a source of harmful contaminants, they do not substantially increase contaminant mobility in most scenarios.

Stephanie Castan, Charlotte Henkel, Thorsten Hüffer, Thilo Hofmann