A single disposable face mask can release more than 1.5 million microplastics into the water after being altered for several hours by UV rays, a recent study by researchers at Concordia University found. Faced with this result, they call for better management of used masks to reduce their impact on the environment.
PhD student Zheng Wang and assistant professor at the Department of Building, Civil and Environmental Engineering, Chunjiang An, spent several months studying the decomposition of disposable masks in a coastal environment.
Their study appeared in a scientific publication in September, Journal of Hazardous Materials, with the participation of specialists from the University of Regina, Fisheries and Oceans Canada, Memorial University and a doctoral student at Concordia.
The famous surgical blue mask, considered to be more effective than those made of fabric or artisanal, represents a means to prevent the spread of COVID-19. Since the start of the pandemic, it is estimated that 129 billion face masks have been used each month in the world, however, having the consequence of leaving traces in the landscape, in particular in rivers.
“We found that the masks were thrown randomly into the environment due to improper management and lack of environmental awareness,” Wang told The Canadian Press.
As the disposable masks are made of plastic, the two Montreal researchers wanted to verify their potential for degradation in a riparian area and their risks.
They then simulated the conditions of a coastal environment on a set of masks by placing them in particular in an uncovered transparent box exposed to UV rays, between one hour and 48 hours.
The masks were then separated into three layers (outer, middle and inner) and according to their exposure time to the rays.
After 18 hours of exposure, “noticeable damage” was observed on the surface of the fibers of the outer and inner layers. After 36 hours, the degradation was more marked as the fibers had fractured creating tiny fragments.
The middle layer of the masks has been shown to be more sensitive to exposure while its fibers are six times smaller than the other two layers.
The different layers were also put in bottles containing either water or sand in order to observe their evolution. In the water, the researchers noted the release of millions of microparticles and the fact that the fibers easily penetrated the liquid, even with the naked eye, after 36 hours of degradation.
Altered by the sand, the number of microparticles released increased further, reaching up to 16 million for a single mask.
The study therefore exposes that the shores play a role in the degradation of masks and the release of particles.
“When the mask is exposed to the shores, it will be affected by natural factors such as irradiation, waves and sand abrasion. These can cause physical and chemical changes to the mask and weaken it. Therefore, after its alteration under these conditions, the mask releases microplastics more easily, ”Zheng Wang analyzes.
Faced with the risks posed by these millions of microplastics for vegetation and animals, Mr. Wang and his colleague want changes to reduce the number of masks left in the environment.
Government, business and the public can make a difference. The doctoral student offers, among other things, best practices in waste management and the manufacture of masks with materials that are less harmful to nature.
The population should also be more aware, according to Mr. Wang, not to throw their masks anywhere. Professor Chunjiang An also suggests adding bins reserved for masks in various public places.