Microplastic Contamination in Freshwater Environments: A Review, Focusing on Interactions with Sediments and Benthic Organisms

Abstract

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.

Spatial and Temporal Distribution of Chemically Characterized Microplastics within the Protected Area of Pelagos Sanctuary (NW Mediterranean Sea): Focus on Natural and Urban Beaches

“…), the accumulation of Anthropogenic Marine Debris (AMDs), also called Marine Litter (ML), has received increasing attention in recent decades [1]. Studies have focused in particular on ML accumulation in the open sea [2][3][4], and in coastal areas [5,6], but also in deep water sediment [7][8][9], in polar areas [10,11], and in freshwater systems [12][13][14][15]. Most of these works confirm that the percentage of "plastics" (including all artificial polymeric types) among the different categories of ML is very high, representing between 61% and 87% of AMDs [16,17].…”

Metal Distribution and Sediment Quality Variation across Sediment Depths of a Subtropical Ramsar Declared Wetland

“…Whilst water samples indicate the present contamination status, sediments potentially provide the contamination history of a system [40]. Sediments also provide important insights into the long-term pollution dynamics and catchment activities of a given aquatic ecosystem, as they act as sinks for nutrients, organic chemicals, pathogens, plastics, and metals [13,16,[41][42][43]. Thus, the analysis of sediments for metal contamination can identify sites with extensive pollution that require further monitoring, and it can aid in identifying metal sources by determining spatial differences in relation to points of human activity [44].…”

Combined Approaches to Predict Microplastic Emissions Within an Urbanized Estuary (Warnow, Southwestern Baltic Sea)

“…Considering land-based MP emissions, major point sources are municipal and industrial wastewaters (Baresel and Olshammar, 2019;Bellasi et al, 2020). Due to high discharge volumes of wastewater treatment plants (WWTPs) they are considered as significant source even though most plants obtain a MP removal efficiency of >90% (with up to 99.9%) (Prata, 2018;Cristaldi et al, 2020;Uddin et al, 2020).…”