This study investigates microplastic pollution from a UK plastic recycling facility and finds a significant presence of microplastics in wash water discharge, particularly in the smaller size range (<10μm). While the installed filtration system removes larger microplastics effectively, smaller particles are still discharged, posing a potential environmental risk.

The authors acknowledge funding from various sources, including the Leverhulme Trust, Carnegie Trust, the European Union's Horizon 2020 Research and Innovation Programme, and the EPSRC. Additionally, they acknowledge support from the plastic recycling company studied, which allowed sample collection and provided information. While this support was crucial for the study, it could potentially introduce a bias toward presenting the company's filtration system in a positive light.

This study provides valuable insights into a relatively unexplored area of microplastic pollution. The methodology used, including Nile Red staining and fluorescence microscopy, is appropriate for the research question. However, several limitations, such as the small sample size, lack of tank homogenization, focus on larger microplastics, reliance on assumptions for calculations, and the single case study design, prevent it from receiving a higher rating. While these limitations are acknowledged by the authors, they do impact the generalizability and robustness of the findings. The identified potential conflicts of interest also warrant consideration.