What we know and what we think we know about microplastic effects - A critical perspective

Microplastic pollution is currently perceived as an environmental hazard, and adverse effects have been reported at various levels of biological organization. However, most experimental designs do not allow plastic-specific effects to be distinguished from those caused by other particles, such as clay and cellulose, which are naturally ubiquitous in the environment. We suggest that microplastic effects reported in recent ecotoxicological studies are similar to those induced by the natural particles. To provide a sound basis for risk assessment, experimental designs must not only be able to disentangle the effects of food limitation and particle toxicity but also demonstrate whether microplastics cause impacts that differ from those induced by natural particles.