Polyester microplastic fibers affect soil physical properties and erosion as a function of soil type

Abstract

Abstract. Microplastics are recognized as a factor of global change contaminating many environmental compartments. Agricultural soils are very likely to receive microplastic contamination and are of particular concern due to their role in food production. Microplastic fibers have already been shown to be able to affect soil properties, but their effect on different soil types is poorly understood. Moreover, limited information is available on how the presence of this pollutant can affect soil water erosion processes, which are extremely important issues in many environments. In the light of this, we performed two experiments (carried out on a microscale) to investigate how the presence of polyester microplastic fibers affects soil physical and hydrological parameters and processes such as aggregate formation and soil erosion in three different agricultural soil types (a Vertisol, an Entisol, and an Alfisol). Our data show that the effects of polyester microplastic fibers on soil physical parameters and erosion are strongly dependent on soil type. We found that microplastic fiber contamination can affect soil bulk density, capacitive indicators of soil physical quality, and decrease the formation of new aggregates (labile in the incubation period applied in our experiments) but did not affect their stability in water. However, we found that polyester microplastic fibers reduced soil loss and sediment concentration, especially in the most erodible soils. In this paper, we provide some hypotheses, but certainly future data are still needed to confirm or disprove our hypotheses. Overall, our results highlight the importance of broadly exploring soil properties, such as texture, mineralogy, organic carbon content, etc., to better understand how the various soil types respond to microplastic fiber contamination.

Nano-Iron Oxide (Fe3O4) Mitigates the Effects of Microplastics on a Ryegrass Soil–Microbe–Plant System

“…The numerous applications of plastics, mainly due to their flexible surfaces and lightweight nature, have greatly boosted plastic production since 1950 to the current manufacture of more than 12.5 million tons annually. , The prevalent use of plastics is projected to generate around 12 billion tons of plastic debris by 2050, and this is likely to lead to severe environmental issues. , Microplastic (MP) particles of synthetic organic polymers with sizes <5 mm have emerged as dangerous pollutants since 1980, and much attention has been paid to the MPs and their relevant health issues. , MPs with different shapes and morphologies such as pellets, fibers, foams, and films have been reported to spread in the atmosphere, terrestrial, aquatic, and soil environments, posing a threat to living beings. , Therefore, MP contamination has been intensifying/escalating rapidly, gaining a lot of research attention and generating the need to understand the impact of MPs on terrestrial environments, especially agriculture. Although the use of plastic in agriculture initially promoted food security worldwide, today it is well-known that it has left a pollution legacy, as MPs threaten food production systems …”

“…The numerous applications of plastics, mainly due to their flexible surfaces and lightweight nature, have greatly boosted plastic production since 1950 to the current manufacture of more than 12.5 million tons annually. 1,2 The prevalent use of plastics is projected to generate around 12 billion tons of plastic debris by 2050, and this is likely to lead to severe environmental issues. 3,4 Microplastic (MP) particles of synthetic organic polymers with sizes <5 mm have emerged as dangerous pollutants since 1980, and much attention has been paid to the MPs and their relevant health issues.…”

Minimal Impacts of Microplastics on Soil Physical Properties under Environmentally Relevant Concentrations

“…The decrease in soil bulk density caused by the incorporation of polyester fibers and polypropylene granules has been reported previously. ,, It has been argued that the decrease in bulk density is caused by the lower specific densities of plastic particles as compared to soil particles . Under the weight-based concentrations, the lower specific density of plastic particles contributes to the decrease in bulk density not only by replacing the volume of a weight-equivalent portion of soil with lighter microplastics, but also by introducing an additional volume (due to plastics taking up more volume than soil particles) to the overall soil-microplastic mixture, which may alter soil structure.…”

“…Indeed, our experiments showed that while polyester fibers and polypropylene granules did not impact overall aggregate stability, polyester fibers were found to clump smaller aggregates together (Figure S10), thereby increasing the proportion of larger aggregates. Similarly, Ingraffia et al also reported no effect of polyester fibers on overall aggregate stability, but an increased percentage of macroaggregates (>600 μm).…”

Microplastics and nanoplastics in agriculture—A potential source of soil and groundwater contamination?

“…MnP-induced changes in available pore space (e.g., reduction in pore size due to filling of pore spaces with MnPs) have been shown to lead to both enhanced or reduced MnP transport (Scheurer and Bigalke 2018;Zhang et al 2019). According to Ingraffia et al (2022) the effects of plastic on soil parameters and soil erosion are strongly dependent on soil type.…”