Quantifying sources and fate of microplastics in the soil-water system. A balance model of an arable land use system in the Netherlands.

Abstract

Microplastics (MPs) could have negative impacts on human health and ecological systems. Information on MPs in arable land is needed, since this system has a variety of sources, could act as a sink and could affect food security. We performed a systematic literature review (SLR) through the PRISMA-method to assess the fate of MPs in an arable land use system. We found input of MPs from irrigation, tire wear particles, compost, atmospheric deposition and the breakdown of plastic litter and output pathways through bacteria and fungi, invertebrates and runoff. We performed a suitability assessment of the analysis of MPs, contamination mitigation measures and geographical factors in the found studies. We applied the SLR results to an arable land use system in the Netherlands with sandy soil and roads, residential areas and ditches in a 1 kilometre radius. The modelling period is 2021-2070 and the population growth was incorporated. An accumulation of 170 – 1,700 kg/ha of MPs in the top soil layer (0-25 cm) was found. The main input pathway is compost (1,8 -24 kg/ha/year) followed by tire wear particles (1,4 – 5,6
kg/ha/year). Breakdown by bacteria and fungi is the main output pathway (4,8 * 10-2 – 6,4 * 10-1 kg/ha/year). Output pathways like percolation, uptake by plants and transport by soil biota are important for the MP balance in the soil, but reliable data of MPs on these pathways are missing. The SLR and model reflect the current state of knowledge and more research on input and output of MPs in arable land use systems is needed.

Date of Award	27 Jun 2022
Original language	English
Supervisor	Angelique Lansu (Examiner) & Jikke van Wijnen (Co-assessor)