Release of Microplastics from Discarded Surgical Masks and Their Adverse Impacts on the Marine Copepod Tigriopus japonicus

Surgical masks (SMs) are the most commonly used personal protective equipment during the COVID-19 pandemic. Due to their vast use and inappropriate disposal worldwide, SMs could potentially cause serious microplastic (MP) pollution in coastal marine environments. This study aimed to investigate the kinetic release of MPs from polypropylene SMs (PP-SMs) in seawater and to evaluate the chronic toxicity of the released MPs to the marine copepod Tigriopus japonicus. On the basis of the results of our kinetic study and available relevant data, we estimated that SMs discarded throughout the year 2020 would lead to >1370 trillion MPs entering the coastal marine environment globally, with a release rate of 396 billion MPs per day. Our results also demonstrated that the copepods ingested the MPs released from PP-SMs, causing a significant decline in their fecundity. The results clearly suggest the MPs released from improperly discarded SMs could have a long-term domino effect on coastal marine ecosystems. To minimize the risk of this emerging threat, better environmental management, policy, and law enforcement for ensuring the proper disposal of SMs are deemed to be necessary.