Micro and nanoplastics ravaging our agroecosystem: A review of occurrence, fate, ecological impacts, detection, remediation, and prospects

Abstract

Micro-and nanoplastics (MNPs) are particles that are smaller than a millimeter in size and have infiltrated both terrestrial and aquatic ecosystems. MNPs pollution have become a widespread problem causing severe adverse effects on human health and the environment worldwide. Once in the environment, these polymers are not easily degradable due to their recalcitrant nature and small size and are easily consumed by aquatic organisms and transported through the food chain, at great risk to human health. Substantial evidence demonstrates the negative effects of MNPs residues on aquatic organisms' reproductive and developmental defects. Similarly, soil flora, soil quality, and plant height have been severely impacted by their presence in the agroecosystem. This is evident in the inhibition of water absorption by blocked seed pores, delayed germination, and the dramatic decline in transpiration rates and growth of plant roots, inevitably leading to drop in biomass and crop production, posing an overall threat to global food security. In this review, we present the impact of MNPs in agroecosystems around the globe, including their sources, occurrence, distribution, transport, and ultimate fate. We recommend using bio-based plastics, eco-friendly remediation strategies, reformed agricultural practices, non-single-use synthetic plastic legislation, and increased plastic waste disposal awareness campaigns as effective tools to mitigate this problem.

Keywords: Agroecosystem; Detection; Microplastics; Nanoplastics; Remediation.

Graphical abstract

Fig. 1

Sources of MNPs in agroecosystems. MNPs from primary and secondary sources reach the agroecosystem directly and indirectly.

Fig. 2

Occurrence, transport, and the fate of MNPs in agroecosystems. MNPs are distributed in agroecosystems horizontally and vertically, affecting plant diversity, soil biota, and nutrient cycling. This results in severe ecological risks.

Fig. 3

MNPs impact on the soil ecosystem. MNPs affect the soil biota, microbiota, and soil element cycling.

Fig. 4

MNPs impact on plants. MNPs attach to plant roots hairs and limit the uptake of nutrients. They can also be absorbed directly by plants and taken up to the leaves, where they affect chlorophyll production, leading to limited photosynthesis and poor growth. MNPs can also alter the pH of the soil, which affects soil microbes and invariably plant growth and performance.

Fig. 5

Schematic representation of interdependencies during MNPs detection.

Fig. 6

Schematic representation of the MNPs extraction procedure using the NaCl floatation method.