Novel insights related to soil microplastic abundance and vegetable microplastic contamination

Abstract

Despite evidence of the uptake of soil microplastics (MPs) by crops, there is a paucity of knowledge regarding the contamination of vegetables in real-world environments with microplastics. This study establishes a correlation between the presence of microplastics in farmland and the concentration of microplastics in crops. The soil samples were found to contain Polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC). The proportions of PE and PP in the soil were considerable, with values ranging from 35 % to 70.6 % and 19.3 % to 50 %, respectively. The levels of PVC, PS and Polymethyl methacrylate (PMMA) in vegetables ranged from 3.64 to 17.37 μg g⁻¹, 0.67 to 2.45 μg g⁻¹ and 0.02 to 0.27 μg g⁻¹, with Chinese cabbage exhibiting the highest concentration at 19.84 μg g⁻¹. The highest level of PMMA was found in eggplant at 0.27 μg g⁻¹. Vegetables sampled, including aubergine, lettuce and Chinese cabbage, contained more than two types of plastic. A correlation coefficient of 0.579 was observed between microplastics in vegetables and soil. This study provides insight into the contamination of environmental soils and different types of vegetables, and the data serve as a reference point for future studies.