Abstract：
Soil environments across the globe, particularly in agricultural settings, have now been shown to be contaminated with microplastics. Agricultural plastics - such as mulching films - are used in close or direct contact with soils and there is growing evidence demonstrating that they represent a potential source of microplastics. There is a demand to undertake fate and effects studies to understand the behaviour and potential long-term ecological risks of this contamination. Yet, there is a lack of test materials available for this purpose. This study describes the manufacture and characterisation of five large (1-40 kg) batches of microplastic test materials derived from agricultural mulching films. Batches were produced from either polyethylene-based conventional mulching films or starch-polybutadiene adipate terephthalate blend mulching films that are certified biodegradable in soil. Challenges encountered and overcome during the micronisation process provide valuable insights into the future of microplastic test material generation from these material types. This includes difficulties in micronising virgin polyethylene film materials. All five batches were subjected to a thorough physical and chemical characterisation - both of the original virgin films and the subsequent microplastic particles generated - including a screening for the presence of chemical additives. This is a critical step to provide essential information for interpreting particle fate or effects in scientific testing. Trade-offs between obtaining preferred particle typologies and time and cost constraints are elucidated. Several recommendations emerging from the experiences gained in this study are put forward to advance the research field towards greater harmonisation and utilisation of environmentally relevant test materials.
摘要：
全球的土壤环境,特别是在农业环境中，现在已经被证明被微塑料污染了。农业塑料-例如地膜-用于与土壤紧密或直接接触，越来越多的证据表明它们是微塑料的潜在来源。需要进行命运和影响研究，以了解这种污染的行为和潜在的长期生态风险。然而，缺乏可用于此目的的测试材料。这项研究描述了五批大型（1-40kg）来自农业地膜的微塑料测试材料的制造和表征。批次由基于聚乙烯的常规覆盖膜或淀粉-聚丁二烯己二酸酯对苯二甲酸酯共混物覆盖膜生产，这些覆盖膜在土壤中被证明是可生物降解的。在微粉化过程中遇到和克服的挑战为从这些材料类型生成微塑料测试材料的未来提供了有价值的见解。这包括将原始聚乙烯薄膜材料微粉化的困难。所有五个批次都进行了彻底的物理和化学表征-原始原膜和随后产生的微塑料颗粒-包括筛选化学添加剂的存在。这是提供必要信息以解释科学测试中的粒子命运或影响的关键步骤。阐明了获得首选粒子类型与时间和成本限制之间的权衡。从这项研究中获得的经验中提出了一些建议，以推动研究领域朝着与环境相关的测试材料的更大协调和利用方向发展。
