Nanoplastics: Status and Knowledge Gaps in the Finalization of Environmental Risk Assessments

Nanoplastics (NPs) are particles ranging in size between 1 and 1000 nm, and they are a form of environmental contaminant of great ecotoxicological concern. Although NPs are widespread across ecosystems, they have only recently garnered growing attention from both the scientific community and regulatory bodies. The present study reviews scientific literature related to the exposure and effects of NPs and identifies research gaps that impede the finalization of related environmental risk assessments (ERAs). Approximately 80 articles published between 2012 and 2021 were considered. Very few studies (eight articles) focused on the presence of NPs in biotic matrices, whereas the majority of the studies (62 articles) assessed the lethal and sublethal effects of NPs on aquatic and terrestrial organisms. Whilst many studies focused on nude NPs, only a few considered their association with different aggregates. Amongst NPs, the effects of polystyrene are the most extensively reported to date. Moreover, the effects of NPs on aquatic organisms are better characterized than those on terrestrial organisms. NP concentrations detected in water were close to or even higher than the sublethal levels for organisms. An ERA framework specifically tailored to NPs is proposed.

Automated summary

Nanoplastics (NPs) are a type of environmental contaminant that has gained increasing attention in recent years. This study reviews the literature on NPs and identifies research gaps in environmental risk assessments. The majority of studies have focused on the lethal and sublethal effects of NPs on aquatic and terrestrial organisms, while research on the presence of NPs in biotic matrices is lacking. Polystyrene NPs have received the most extensive research attention. NP concentrations detected in water are close to or higher than sublethal levels for organisms. A specific ERA framework for NPs is proposed.