Understanding the Risk of Microplastic Dermal Absorption

Microplastics are a growing public health concern globally, posing an unprecedented risk both to the environment around us and to our bodies. The major focus of research and policy so far has been on inhaled and ingested microplastics which contribute greatly to the physiological burden of microplastics. However, despite the continued growth of the skincare and cosmetics industry, there remains a significant research gap in the mechanisms and risks of dermal absorption compared to other routes. The aim of this review is to first outline how the skin functions as a barrier and then how microplastics and secondary particles may enter the skin, leading to damaging effects. Critical factors that may influence dermal absorption are discussed including chemical additives in cosmetic products, particle morphology and existing barrier damage. Understanding how particular environmental and health conditions may influence the absorption of microplastics will help drive regulation and reform around microplastic usage in skincare products. This review highlights the need for more rigorous research to better characterise the risk of microplastic dermal absorption and the mechanisms by which microplastics can bypass the skin barrier to mitigate against them. Through the development of more physiologically relevant models and reproducible experimental designs, understanding of microplastics will continue to improve and hopefully lead to better regulation to limit the health and environmental impacts.