Microplastics in the soil environment: A critical review

Abstract

Environmental pollution of microplastics (MPs) is known to be anthropogenically mediated menace to biosphere and becoming a debatable concern globally. Large quantities of plastic fragments are left behind after crop cultivation. The leftover plastic debris, gradually degrade into minute fragments with a diameter of less than 5 mm, known as MPs. MPs are responsible for many changes in the soil physicochemical characteristics, including porosity, enzymatic activities, microbial activities, plant growth, and yield. Because of their ubiquitous nature, high specific surface area and strong hydrophobicity, MPs play an important role in the transportation of toxic chemicals such as plasticisers, polycyclic aromatic hydrocarbons (PAHs), antibiotics, and potentially toxic elements (PTEs). MPs may be transported deep into the soil and can pollute underground water. This review paper investigates the deleterious effects of MPs on the soil environment, enzymatic activities, soil microbes, flora, fauna and crop production, and highlights the general concept of MPs contamination as well as its possible environmental consequences. The review also converses some of the key areas for future research and for key stakeholders concerned with policymaking • Microplastics (MPs) pollution has become an important public and scientific topic. • Residual remains of mulching in the form of MPs cause soil pollution. • MPs alter the characteristics of soil flora and fauna. • MPs act as a vector for environmental pollutants in the soil environment. • New agronomic technology and biodegradable mulch films need to be developed.