Whether microplastics cause different effects than inert natural particles, and how to create relevant testing materials, are key questions in microplastics research. We prepared Environmentally Relevant Microplastic (ERMP) and Mineral Microparticle (ERMS) mixtures with similar levels of polydispersity and tested their 28-day chronic effects on the reproduction and growth of L. variegatus at two different organic matter (OM) contents (average and enriched). Additionally L. variegatus was exposed to ERMP and ERMS to study the particle egestion for 14 days. We observed no differences in growth or reproduction between ERMP and ERMS at particle concentrations of up to 10% (v/v). In contrast, organisms exposed to enriched OM content increased their growth with 30% and increased reproduction with 20%. For ERMP with an enriched OM content, reproduction was reduced with an effect threshold EC₅₀ of 13.68 ± 5.54% (v/v). After 14 days of exposure to 5% ERMP, the egestion of faecal pellets was higher compared to exposure to 5% ERMS, suggesting that in order to acquire the same amount of nutrition, L. variegatus is spending more energy. With this study, we demonstrate that refinements in the manufacturing of environmentally diverse particle mixtures can contribute to a more realistic testing of particle effects.

中文翻译：

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微塑料与天然矿物颗粒。如何在保持环境相关性的同时创建和测试它们


微塑料是否会引起与惰性天然颗粒不同的影响，以及如何制造相关的测试材料，是微塑料研究中的关键问题。我们制备了具有相似多分散性水平的环境相关微塑料 （ERMP） 和矿物微粒 （ERMS） 混合物，并测试了它们在两种不同有机质 （OM） 含量（平均和富集）下对杂色乳杆菌繁殖和生长的 28 天慢性影响。此外，L. variegatus 暴露于 ERMP 和 ERMS 以研究颗粒反应 14 天。我们观察到在颗粒浓度高达 10% （v/v） 时，ERMP 和 ERMS 之间的生长或繁殖没有差异。相比之下，暴露于富集 OM 含量的生物体的生长速度提高了 30%，繁殖速度提高了 20%。对于富含 OM 含量的 ERMP，效应阈值 EC₅₀ 为 13.68 ± 5.54% （v/v） 时，繁殖能力降低。暴露于 5% ERMP 14 天后，粪便颗粒的发情量高于暴露于 5% ERMS 的粪便颗粒，这表明为了获得相同数量的营养，杂色乳杆菌消耗了更多的能量。通过这项研究，我们证明了环境多样化的颗粒混合物制造的改进有助于对粒子效应进行更真实的测试。