NANOplastics Toxicity Evaluation and Risk (management) in teRrestrial Agro-Ecosystems (NanoTERRAE)

Plastic has been recognised as one of the major anthropogenic stressors affecting ecosystems. Microplastics, and more recently nanoplastics (NPs) have been reported in different environments, from surface waters and agricultural soils up to remote polar ice cores. Their widespread occurrence and the foreseen increasing trend of their environmental levels have led to a growing concern due to their potential impact on biota and human health. Compared to larger plastics, NPs have high surface reactivity and they can easily interact with biological systems, cross cellular barriers and generate toxicity. At present, few data on NP toxicity are available on soil organisms, although evidence shows that they are likely exposed to NPs as a result of plastic degradation. The main criticisms to these data are related to their low environmental relevance, as they were mainly conducted as short incubations, testing a single polymer class (e.g. polystyrene) as model NPs at concentrations one to several orders of magnitude higher than the environmental levels, thus limiting extrapolation and comparison among studies. The project NanoTERRAE aims to develop effective science-driven tools for the environmental risk assessment of NPs in agroecosystems. Four main objectives will be addressed: (i) Evaluate the toxicity of model NPs as a proxy for the environmentally relevant NPs on model terrestrial species representative of the soil communities; (ii) Assess the main features dictating NP uptake, translocation and excretion over time, with reference to their potential bioaccumulation in tissues and organs; (iii) Model NP effects on soil organisms in a risk management framework; (iv) Ensure prompt dissemination of the results and data accessibility through an Open science policy. We propose to conduct in vivo chronic ecotoxicity tests using two model species as representative of the soil communities, the earthworm Eisenia fetida and the springtail Folsomia candida. The organisms will be exposed to environmentally relevant concentrations of NP proxies with different size and polymer as well as mixtures, to represent the physical and chemical heterogeneity of NPs found in agricultural soils. At relevant time-points, NP effects on survival, growth, reproduction and behaviour will be quantified as well as several biomarkers evaluated to disclose physiological alterations and estimate repercussions at higher ecological level. In parallel, we will evaluate possible sites of accumulation tracing labelled NPs inside organisms’ tissues and organs. The effect-based data obtained will be used to estimate NP safety levels and risk in agroecosystems filling these knowledge gaps and providing useful tools for the regulatory community at national and international level. NanoTERRAE achievements will have an impact on the scientific community and the public, promoting science-driven measures to monitor and manage NP pollution in agroecosystems in line with United Nation 2030 Agenda.