Microplastic Pollution in Terrestrial Systems: Sources and Implications for Soil Functioning and Plant Performance

Abstract

Recent years have seen a significant increase in microplastic contamination across terrestrial ecosystems, facilitated by various pathways such as atmospheric deposition, wastewater irrigation, and agricultural plastic mulching. This persistence of microplastics in soil raises concerns about their profound impacts on soil health and ecosystem dynamics. Key studies have highlighted detrimental effects, including reduced soil moisture retention, altered soil microbiota composition, and disrupted nutrient cycling processes. Moreover, microplastic pollution adversely affects soil biota, notably earthworms, crucial for soil nutrient cycling and structure maintenance, exhibiting reduced growth rates and increased mortality upon exposure. Notably, microplastics also influence soil microorganisms, potentially compromising overall soil health and ecosystem functioning. Co-exposure of microplastics and other contaminants can also synergistically exacerbate toxicity, impairing ecological balance. Evidence suggests negative repercussions on plant growth, including diminished seed germination rates and altered nutrient profiles in exposed plants. These findings underscore the urgent need for comprehensive reviews to synthesize existing knowledge, and identify research gaps, necessitating a focus on mitigation strategies. Addressing these issues is critical for safeguarding terrestrial ecosystems and ensuring sustainable environmental management in the face of increasing microplastic contamination.