Nano- and microplastics (NMPs) are ubiquitous, persistent, and, as is now widely recognised, a global problem for humans and the environment. Because of the many different types of plastic from which NMPs are derived, conducting a general risk assessment is challenging. In addition, many plastics contain additives such as UV stabilisers or plasticisers that have hormonal effects – so-called endocrine disruptors (EDs) – and can easily be released from the plastics. Furthermore, some endocrine disruptors can strongly adhere to the surface of NMP particles and spread with them throughout the environment. The effects of endocrine disruptors on humans and the environment remain partially unclear, as they can be very diverse and species-specific, making monitoring difficult. However, a causal link between exposure to endocrine disruptors and various human diseases has now been established. Adverse effects have also been observed in other organisms following exposure to endocrine disruptors, particularly in relation to reproduction. Even if greener alternatives (e.g. bioplastics) could replace conventional plastics in the future, a significant influx of NMPs into the environment and the use of hormonally active substances can still be expected in the coming decades. Therefore, it is of utmost importance to establish additional test systems to protect human health and the environment, especially at the level of organisms that may facilitate the trophic transfer of EDs into the food chain. This dossier explores general issues related to NMPs, EDs, and ecotoxicological risk assessment using the aquatic snail Biomphalaria glabrata.