A multi-analytical approach to investigate UV-induced degradation and micro/nanoparticle release from disposable plastic face masks

Disposable plastic face masks (DPFMs), widely used during the COVID-19 pandemic, have raised environmental concerns due to their improper disposal accompanied by unknown environmental degradation. This study adopts a dual approach to assess both the material degradation and the pollutant release of DPFMs subjected to long-term ultraviolet (UV-B) aging in water, simulating environmental exposure for up to one year. Physicochemical changes were monitored using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), mechanical testing, water contact angle measurements, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Leachates were analyzed by non-purgeable organic carbon (NPOC), Py-GC/MS, inductively coupled plasma mass spectrometry (ICP-MS), and atomic force microscopy (AFM). The degradation of the DPFM layers was evidenced by structural weakening, a 2.46 % mass loss, and an increase in carbon release (NPOC up to 50 mg C/L). SEM and AFM confirmed the formation and release of micro- and nanoplastics, while Py-GC/MS identified oxidized polypropylene fragments in leachates. Metals such as barium (67.2 µg/L), zinc (14.1 µg/L), and copper (3.2 µg/L) were detected for the one-year testing. By combining material-level degradation analysis alongside leachate characterization, this work provides a comprehensive view of the environmental behavior of aged DPFMs. The overall findings highlight the potential of DPFMs to act as long-term sources of polymeric particles and chemical contaminants, underscoring the need for ameliorated waste management and further ecotoxicological assessment.