Face mask exposure to environmental conditions: In situ physical and chemical degradation and interaction with marine organisms

It is widely recognized that the measures adopted during the pandemic resulted in a significant number of face masks entering marine environments. One key aspect is to investigate the behavior of such contaminants in coastal environments. In the present study, in situ experiments were carried out to investigate the physicochemical changes of two types of face masks, as well as their interaction with intertidal biota. Chemical analyses showed no notorious signs of photo-oxidation while confirming that face masks are entirely composed of synthetic polymers. However, scanning electron microscopy showed an affectation of the physical structure on the outer layer of KN95 respirators, as well as the presence of environmental elements accumulating. Interaction with intertidal biota suggested that face masks serve as a suitable substrate and hiding spot for bivalves and polychaetes. Investigating the alteration of such contaminants in the intertidal shore provides new insights into their behavior after entering the ocean.