Assessing microplastic translocation from contaminated agricultural soils to food crops

Abstract

Microplastic (MP) and nanoplastics (NP) pollution presents a critical, globally pervasive environmental challenge, fundamentally threatening the sustainability of agricultural soil health and food production. The current state of knowledge regarding the impact of these ubiquitous plastic particles, typically defined as those between 1 μm and 5 mm, in terrestrial ecosystems. The paper identifies key pathways of contamination into farmlands, primarily stemming from the pervasive degradation of plastic mulching films. The extensive land application of sewage sludge (biosolids) as fertilizer and the use of contaminated wastewater for irrigation. The accumulation of MPs/NPs in the soil matrix is shown to induce significant ecological stress. Key findings reveal detrimental effects on soil physicochemical properties, disruption of native microbial communities and a measurable reduction in crop performance, evidenced by compromised nutrient uptake and photosynthetic efficiency. A major concern addressed is the critical evidence of MP/NP translocation from the soil into the edible tissues of agricultural crops, which creates a direct pathway for human exposure and subsequent health risks via the food chain. To combat this rising threat, the paper underscores the urgent need for a cohesive, global response. Sustainable solutions must involve implementing robust policy frameworks, such as the FAO’s Voluntary Code of Conduct, accelerating the transition to certified biodegradable plastic alternatives and drastically improving international waste management, recycling infrastructure and use of biochar in agricultural lands. Future research is essential to quantify the full spectrum of long-term ecological risks, model MP transport dynamics and comprehensively assess the human health implications.