Evidence Reviews on Analysis, Prevalence & Impact of Microplastics in Freshwater and Estuarine Environments. Evidence Review 1 Are the current sampling and analytical methods scientifically robust and appropriate?

Abstract

This Rapid Evidence Assessment used the systematic review procedure to assess the current evidence available on the reliability/robustness of sampling and analytical methodology used to provide data sets describing the presence of microplastics in the environment. A review was conducted of primary literature, including grey literature, which reported sampling and analytical methodologies that have been used to determine the presence of microplastics in aquatic matrices; the abundance, substance, state, morphology, dimensions and sources of microplastics reported to have been found in freshwater and estuarine environments. Evidence was acquired according to a predefined set of questions, compiled into a database containing full details of the source and its relevance to the project questions. The evidence was analysed, taking into account reporting biases in the literature, to produce a digestible summary of the evidence to answer the main project question and sub-questions, namely, Are the current sampling and analytical methods used to provide data on the presence of microplastics in freshwater and estuarine matrices as well as other environmental materials scientifically robust and appropriate? a) Are the methods transferable to different sample matrices and can they be used to assess changes to the microplastic profile and properties at different stages from sink to river and river to tap? b) With samples from different matrices, what pre-processing of samples is used? c) If the method has been used in marine environments, does it require any modification to be used in equivalent freshwater environments? d) To what extent can the method provide information on different characteristics of microplastics such as substance, state, morphology and dimensions? e) Does the sampling method used address spatial and temporal variation adequately?