Release of microplastics from used disposable masks and wet wipes in artificial seawater under sunlight

The global increase in plastic waste has raised significant concerns regarding microplastic pollution and its ecological and human health impacts. This study investigated the release of microplastics (MPs) from surgical masks, N95 masks, and wet wipes in artificial seawater under natural sunlight exposure and non-exposure over a 10-day period. Mass loss analysis revealed that surgical masks exhibited the greatest mass loss, followed by N95 masks and wet wipes. Fibres constituted the dominant morphology of the released particles, followed by fragments. In addition, Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy analysis confirmed that polypropylene (PP) was the primary polymer in masks, while wet wipes contained polyester-based materials. This study demonstrated that exposure to natural sunlight in artificial seawater for 10 days significantly increased microplastic release from N95 masks, wet wipes, and surgical masks compared with non-sunlight conditions (p < 0.05). Microplastic release reached 695.00 ± 100.22, 1205.33 ± 43.10, and 2619 ± 608.28 particles per item under sunlight exposure, whereas the corresponding values under non-sunlight conditions were 516.33 ± 26.73, 698 ± 99.98, and 676.00 ± 146.00 particles per item, respectively. The results indicate that disposable masks and wet wipes can release microplastic particles in artificial seawater under both sunlight and non-sunlight conditions. Furthermore, exposure to natural sunlight significantly accelerates material degradation and enhances microplastic release, suggesting that the improper disposal of these materials may contribute to microplastic pollution in marine environments.