Occurrence, Distribution and Characteristics of Microplastics in Agricultural Soil Around a Solid Waste Treatment Center During the Covid-19 Pandemic

The COVID-19 pandemic has driven the explosive growth of microplastics (MPs) related to medical waste and takeaway services, increasing the burden of solid waste treatment systems while also potentially threatening the surrounding environment. But data on the influence of solid waste treatment systems on MPs pollution to surrounding agricultural soil during the COVID-19 pandemic are lacking. In this study, the occurrence, characteristics and distribution patterns of MPs in agricultural soil surrounding a solid waste treatment center in southeastern China were investigated. The results showed that the abundance of MPs ranged from 280 to 2360 items/kg, with an average value of 835 items/kg, small-sized particles were dominant, the most frequent shape was fragmented. The mean abundance of MPs in the downwind area was higher than that in other areas, though no significant difference was discovered. A high amount of PE (52.86%) and PP (27.14%) were identified, suggesting that the MPs primarily originated from agricultural activities. SEM-EDS images illustrated that the MPs were significantly weathered and eroded, and different metal elements observed on different surface sites of individual MP, implied that MPs may migrate as heavy metal vectors to threaten soil and agricultural food safety. Based on these results, we estimated that the solid waste treatment center has a small contribution to the propagation of MPs, mainly the small-particle MPs, and strong management is beneficial in limiting MP dissemination to the surrounding environment. Nevertheless, special attention should be paid due to the higher risk of small-particle MPs.