Disposable face masks lead to more microplastics in waterways: Canadian study

A used protective face mask is seen discarded on the ground in Vancouver, B.C. in May 2020. THE CANADIAN PRESS/Jonathan Hayward

The use of disposable face masks as a result of the COVID-19 pandemic has led to more microplastics in waterways, a recent study from Canadian researchers has found.

Microplastics are tiny plastic particles that are less than 5 millimetres long and are created through the degradation of discarded plastic-containing products. These particles have been observed polluting various natural ecosystems, particularly aquatic environments.

The study was published in the Journal of Hazardous Materials in September and involved researchers from Concordia University, the University of Regina, Fisheries and Oceans Canada and Memorial University. They looked into how disposable masks break down in a shoreline environment.

"With the increasing presence of waste masks on shorelines, it is critical that the environmental effect of disposable masks on the shoreline environment be evaluated in a timely manner," the authors wrote.

Disposable surgical masks are typically made from a type of plastic called polypropylene and consist of three layers – outer, middle and inner. Many masks also contain some chemical additives, which can also be released into waterways as the masks break down.

The researchers exposed masks to simulated shoreline conditions and observed how the masks broke down. They exposed the masks to UV light for up to 48 hours while keeping a control group of masks wrapped in aluminum foil.

After 18 hours of UV exposure, the masks showed "obvious deformation or damage" on the inner and outer layers, the researchers wrote. After 36 hours, most of the fibres in all of the layers of the masks were damaged, creating miniscule fibre fragments.

UV exposure resulted in more than 1.5 million microplastic particles being released from a single mask, compared to just over 483,000 particles for masks not exposed to UV.


"Masks have become a part of daily life, both during and after the pandemic. So, it is necessary to establish strategies to deal with mask waste," Concordia PhD student and lead author Zheng Wang told CTVNews.ca over the phone on Wednesday.

An estimated 129 billion face masks are used globally each month, according to a June 2020 study led by Portuguese researchers. Wang says the findings underscore the need for governments, researchers and industry to collaborate and find ways to prevent further pollution in our waterways.

"For the public, we need to increase awareness to not discard masks randomly. For governments, they need to adopt new regulations to establish best practices. For industries, we need to develop new biodegradable materials for masks and develop new production technologies to reduce the environmental impact," Wang said.