Analysis and Effects of Microplastics in the Agricultural Soils

Abstract

Microplastics (MPs) are pertinacious contaminants which are threatening the delicate balance of the ecosystem. Over the years, various studies have reported the presence of MPs in the marine environment through case studies and reviews, but its presence in the agricultural soils is not fully understood. To date, there exists no standardized methodology for sampling, extraction and characterization of MPs in the agricultural soils. This review aims at encapsulating the different techniques used for sampling and extraction of MPs, and includes the methods employed for identification and quantification of MPs in the soil environment. Flotation method, pressurized fluid extraction and elutriation are some of the different techniques used for MPs extraction that usually influence the characterization step. Visual identification through microscope and scanning electron microscope and chemical identification via Fourier-transform infrared (FITR) and Raman spectrometry, are the main techniques that are used for the identification of MPs. The fate and dispersion of MPs in the agricultural soil are discussed, as well as their interaction with the soil biota. The main findings of this review show that further research is needed on the sampling methods as well as analytical techniques so as to contribute to standardizing MPs characterization in the soil environment, potential toxicity effects along the food chain, and global policies for sustainable development.