Single-use plastics are like a double-edged sword: on the one hand, plastics have revolutionized many areas of everyday life, on the other hand, their mass use leads to a waste volume that is now considered a major environmental burden. Plastics are also one of the most concerning environmental pollutants in public perception. Due to their high persistence, plastics accumulate in ecosystems and, upon exposure to UV radiation and due to mechanical abrasion, are degraded into tiny fragments – nano- and microplastics – detected in almost all environmental compartments worldwide. Despite considerable research efforts in recent years, our knowledge of the exact extent of pollution and the effects of nano- and microplastics on organisms and ecosystems is poor. This also complicates the assessment of environmental implications of the current contamination level with nano- and microplastics, including environmental risk assessment. The risk assessment process is particularly difficult because the plastic particles in the environment differ in terms of their chemical composition, shape, and size – properties which strongly influence the toxicity of micro- and nanosized particles. In addition, there is still a lack of internationally agreed and standardized measurement methods for the detection and quantification of nano- and microplastics in the environment and the investigation of their effects.

This special issue aims to collect and report the state-of-the-art information on the various aspects of the occurrence, environmental fate and toxicity of nano- and microplastics.