The pervasive use of plastics together with inadequate waste management has led to a global contamination of ecosystems with end-of-life plastic products. The global plastic pollution has been shown to pose a planetary threat because it is causing planetary-scale exposure that is not readily reversible. Thus, the presence of (micro-scale) plastics has received increasing attention over recent years, not only within the scientific community but also among regulators, policy makers and the general public. Originally, being a topic of interest in marine research, the concern about these materials has expanded to freshwater and most recently also to terrestrial and atmospheric systems. One of the major proposed knowledge gaps is the understanding of relevant environmental transformation and transport processes. Plastic particles released in the environment are subjected to various aging process including biotic (biofilm formation) and abiotic aging (UV radiation, oxidation, and physical stress). These processes lead to an alteration in the physical and chemical properties of the polymeric particle and may ultimately result in an embrittlement and fragmentation. Understanding the interactions between microplastics and those contaminants remains important for evaluating the materials' impact on the environment. Despite the number of sorption studies available for microplastics, there is little information on how ageing of the particles influences their properties and ultimately the sorption and leaching behavior.