Inorganic Additives Induce More Small-Sized Microplastics Releasing from Medical Face Masks

Area of Science:

• Environmental Science
• Materials Science
• Polymer Chemistry

Background:

• Microplastic release from medical face masks (MFMs) is a known issue.
• The specific role of inorganic additives, such as calcium carbonate (CaCO3), in microplastic emission has not been previously identified.

Purpose of the Study:

• To comparatively analyze microplastic release from MFMs with and without CaCO3 additives.
• To elucidate the influence of inorganic additives on the photoaging and degradation of mask materials.

Main Methods:

• Surface-enhanced Raman spectroscopy (SERS) was used to detect micro- and nanoplastic release.
• Simulated Raman scattering (SRS) was employed for stereoscopic characterization of additive mixing and for 3D imaging of internal plastic aging.
• Radical quenching experiments were conducted to identify the chemical species responsible for accelerated aging.

Main Results:

• Inorganic additives, specifically CaCO3, were found to significantly accelerate the photoaging of plastic materials in MFMs.
• This accelerated aging leads to an increased emission of smaller-sized microplastics.
• Carbonate radicals were identified as the primary mechanism driving this phenomenon.

Conclusions:

• Inorganic additives in MFMs play a critical role in enhancing microplastic pollution.
• The study reveals a previously unrecognized hazardous potential of common mask additives.
• Findings underscore the need to consider additive impacts in the design and disposal of polymer-based products.