Plastic is one of the most commonly produced and used materials in the world due to its outstanding features. However, the worldwide use of plastics and poor waste management have led to negative impacts on ecosystems. Plastic degradation in the environment leads to the generation of plastic particles with a size of <5 mm, which are defined as microplastics (MPs). These represent a global concern due to their wide dispersion in water environments and unclear potential ecotoxicological effects. Different studies have been performed with the aim of evaluating the presence and impacts of MPs in the marine environment. However, the presence of MPs in freshwater systems is still poorly investigated, making data retrieval a difficult task. The purpose of this review is to identify the main aspects concerning MPs pollution sources in lakes and rivers, with a focus on freshwater sediments as a site of accumulation and as the habitat of benthic organisms, which are key components of food webs and play a fundamental role in energy/contaminant transfer processes, but are still poorly considered. Through this review, the sources and fate of MPs in freshwater are analysed, ecotoxicological studies focused on sediments and benthic fauna are exposed, the most frequently used sampling and analysis strategies are reported, and future trends of MPs analysis in this field are proposed.

Climate change impacts on lakes: an integrated ecological perspective based on a multi-faceted approach, with special focus on shallow lakes

Research on microplastics (MPs) in the terrestrial environment is currently at a still embryonal stage. The current knowledge concerning poorly known diffuse sources of MPs pollution in terrestrial ecosystems have been considered in this work. In addition, a particular focus on the presence, mechanism of absorption and effects of MPs in plants has also been provided. Research concerning microplastics in urban areas and their intake by Tyre and Road Wear Particulates (TWRP) demonstrated a high contribution of this plastic debris to microplastic pollution, although quantification of these inputs is challenging to assess because studies are still very few. Around 50% of particles are expected to remain in the roadside soil, while the rest is transported away by the runoff with high concentrations of TRWP with a size ranging between 0.02 and 0.1 mm. Natural and anthropic environments like temporary ponds, stormwater retention ponds and small waterbodies were considered sensitive connecting ecosystems rich in biodiversity between terrestrial and aquatic environments. Even if studies are not yet exhaustive and just eight studies were currently published concerning these ecosystems, considerable values of MPs were already observed both in the sediment and water phase of ponds. Although still poorly explored, agricultural environments were already demonstrated to hide a significant number of microplastics linked mainly to agricultural activities and practices (e.g. mulch, sewage and compost fertilisation). However, the microplastics transportation processes into the soil are still understudied, and a few works are available. Microplastics and primarily nanoplastics presence was also observed in common edible plants (fruit and vegetables) with alarming Estimated Daily Intakes ranging from 2.96 × 10⁰⁴ to 4.62 × 10⁰⁵ (p kg^-1 day^-1) for adults depending on species. In addition, adverse effects on plants growth, photosynthetic activity, antioxidant system and nutritional values of several common fruits and vegetables were also demonstrated by several studies.