Direct and Indirect Impacts of Disposable Face Masks and Gloves on Freshwater Benthic Fauna and Sediment Biogeochemistry

Abstract

To reduce virus transmission, the use of personal protective equipment (PPE) increased substantially during the COVID-19 global pandemic. As a result, disposable face masks and gloves made from plastic polymers rapidly entered the environment, with little understanding of ecological impacts. Many plastic polymers sink to the bottom of freshwater bodies, either immediately or following biofouling and degradation, posing a potential risk to the benthos. We assessed the acute and chronic ecotoxicity of disposable polypropylene face masks and nitrile gloves on Lumbriculus variegatus, a benthic ecosystem engineer. In microcosm experiments, we also investigated direct impacts on sediment biogeochemistry and indirect impacts mediated by toxicity to L. variegatus. Exposure to fragments of both masks and gloves decreased vitality of L. variegatus. Gloves were acutely toxic, but mask toxicity was mediated by physical interactions. Glove fragments significantly decreased nitrogen removal and phosphorus release to the water column. Both materials suppressed the ecosystem engineering role of L. variegatus by decreasing its impact on microalgal primary production, net ecosystem metabolism, and sediment nitrate consumption. The influx of PPE to the environment may have profound and cascading negative impacts on benthic organisms and ecosystem function, suggesting the need for improved management of PPE litter.