COVID-19 related personal protective equipment (PPE) litter in salt marsh habitats: Degradation and microplastic emission

The use of personal protective equipment (PPE) has increased significantly since the onset of the COVID-19 pandemic in late 2019. Face masks, gloves, and sanitizing wipes are common types of PPE that have been used during the pandemic, all of which can be comprised of plastic polymers. PPE items have been shown to generate microplastic fibers and fragments, but their degradation in the natural environment is understudied. The objective of this study was to quantify the degradation and microplastic emission of common plastic PPE items in a salt marsh, which serve a vital role in maintaining the health and resilience of coastal ecosystems and have been shown to be vulnerable to pollutants. Four types of PPE items (face masks, gloves, compostable and conventional sanitizing wipes) were deployed in an intertidal salt marsh for up to 16 weeks. Changes in weight, biofilm formation, surface area, and microplastic emissions were measured at 0, 2, 4, 8, and 16 weeks. All PPE degraded in the environment and emitted particles beginning at 2 weeks, and emission increased over time. Sanitizing wipes produced the highest number of microplastics at the end of 16-weeks. Compared to previous studies in the same area, these results suggest that plastic PPE items may degrade faster than other plastics. This study is one of the first to quantify PPE degradation and microplastic emission in the natural environment and supports the notion that single-use PPE litter has the potential to be a source of microplastic pollution in coastal environments.