Reply to road markings and microplastics- a critical literature review.

This is a reply to the recently published paper Road markings and microplastics- A critical literature review. In our opinion, that paper presented a deceptive picture, of why we found it necessary to write a short reply where we comment on two major flaws: the stated lack of road markings in environmental samples, and the definition of microplastics. We discuss possible reasons for the absence of positive findings in environmental samples and relate that to two of the major issues within the research area of microplastics- the complexity of environmental samples and the analytical difficulties. We also argue that it can be relevant for upcoming studies to report both total microplastic concentration and polymer content to facilitate the comparison between studies since the definition of microplastics might change over time. [ABSTRACT FROM AUTHOR]