Comparison between discarded facemask and common plastic waste on microbial colonization and physiochemical properties during aging in seawater

• Published in: Journal of hazardous materials Vol. 455; p. 131583
• Main Authors: Ma, Jie, Chen, Fengyuan, Chen, Ciara Chun, Zhang, Zhen, Zhong, Zihan, Jiang, Hao, Pu, Junbao, Li, Yanping, Pan, Ke
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.08.2023
• Subjects: Aging; Bacteria - metabolism; Biodegradation, Environmental; Biofouling; COVID-19 - prevention & control; Humans; Marine; Masks; Microplastics; Pandemics; Plastics - metabolism; Seawater; Aging; Microplastics; Marine; Masks; Biofouling
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.131583

Facemasks are indispensable for preventing the spread of COVID-19. However, improper disposal of discarded facemasks has led to their contamination in the marine environment. To understand the environmental risk of this emerging plastic pollution, it’s important to clarify the features that distinguish discarded facemasks from common plastic waste during aging. This study compared the microbial colonization, degradation-related enzymes, and physicochemical properties among surgical masks, polystyrene cups, polycarbonate bottles, and polyethylene terephthalate bottles in their aging processes in natural seawater. Compared to the other plastic wastes, surgical masks were colonized by the most diverse microorganisms, reaching 1521 unique prokaryotic OTUs after 21-day exposure in seawater. Moreover, the activity of eukaryotic enzymes associated with plastic degradation was 80-fold higher than that in seawater, indicating that the colonized eukaryotes would be the major microorganisms degrading the surgical masks. Meanwhile, the nano-sized defects (depth between 8 and 61 nm) would evolve into cracks of bigger sizes and result in the breakage of the microfibers and releasing microplastics into the ocean. Overall, our study demonstrated a distinctive plastisphere occurred in surgical masks from both microbial and physiochemical aspects. This work provides new insights for assessing the potential risk of plastic pollution caused by the COVID-19 pandemic. [Display omitted] •Biofouling and aging were compared among facemasks and common plastic wastes.•Distinct marine colonizers occupied the surface of masks.•Higher activity of eukaryotic enzymes related to biodegradation was present on masks.•Masks with huge surface area provide multiple sites for environmental interactions.•Masks show a significantly higher degradation degree at the micro- and nanoscale.