The study of plastic pollution in soils, both in terms of the mobility of micro- and nanoplastics and in terms of ecotoxicity, is of crucial importance today. This pollution is found in both terrestrial and marine environments. High concentrations of environmental plastics are found in landfill sites, agricultural soils and rivers. These plastic fragments break down in the environment and can release the additives used in their formulation, such as endocrine disruptors (phthalates and bisphenols) and trace metals. These microplastics, nanoplastics and their additives then have the capacity to be mobilised in different environmental compartments (soils, river systems and organisms). Nanoplastics can also heteroaggregate with soil constituents and adsorb or release other contaminants present in the soil. However, the mobility and ecotoxicity of plastic fragments in terrestrial ecosystems are still poorly understood, and research on these subjects is in its infancy.