Environmental impact of disposable face masks: degradation, wear, and cement mortar incorporation

Polypropylene (PP) disposable face masks (DFMs) are essential for limiting airborne infectious diseases. This study examines the behavior of DFMs under three scenarios: (i) exposure to the natural environment, (ii) simulated high-energy aquatic environments through an abrasion test, and (iii) incorporation into cement-based mortars. In the natural weathering experiment, after 117 days, the DFMs exhibited photodegradation, resulting in chemical alterations in carbonyl and hydroxyl groups. This degradation led to the breakdown of the polymer and the release of microplastics and nanoplastics. Controlled abrasion tests, conducted in a Denver ball with water, sand, and ceramic balls for 2 h, confirmed that water is a critical factor for fiber release from DFMs. These tests resulted in the release of 0.26 g of PP fibers from 20 DFMs (weighing 62 g in total) with a diameter of 20 µm. Weathering and abrasion tests indicated rapid release and degradation of microplastics and nanoplastics, underscoring the importance of pursuing actions like reuse. Ecotoxicological tests revealed that leachates from the DFM-incorporated mortars showed no adverse effects on Daphnia magna or Selenastrum capricornutum, unlike the reference mortar, which caused substantial toxicity to Daphnia magna. Incorporating PP fibers from DFMs into cement-based mortars showed promising potential, as indicated by favorable ecotoxicity and chemical leaching test results.