Hong Kong Researchers Say COVID-19 Mask Waste Pollutes Water Equivalent To 54,800 Olympic-sized Swimming Pools

JAKARTA - Surgical mask waste during the COVID-19 pandemic that flows into the ocean can release microplastics as they degrade, contaminating an amount of water equivalent to 54,800 Olympic-sized swimming pools.

Dr. He Yuhe of City University's State Key Laboratory of Marine Pollution made the discovery looking at masks discarded on local beaches, which has seen an influx of local visitors looking for a weekend spot amid the coronavirus pandemic.

"The COVID-19 pandemic is still ongoing, and it's natural that if people wear surgical masks, people throw them away," said Dr. He quoted the Korea Times from the December 25 SCMP.

"We strongly urge residents to be vigilant when in rural areas, properly dispose of used masks so that they are not swept into the sea by wind or rain," he said.

Medical masks are becoming a necessity to prevent the spread of COVID-19, with an estimated 129 billion used worldwide each month by 2020.

Because masks are made of woven plastic fibers, discarded face coverings can take between 100 and 1,000 years to fully decompose.

The United States National Oceanic and Atmospheric Administration defines microplastics as any type of plastic fragment with a diameter of less than 5 mm.

Once at sea, ocean currents and ultraviolet rays from the sun break the mask into tiny fragments or fibers. He was able to imitate the motion of waves in the laboratory by placing them in a bottle of artificial seawater and shaking it.

His laboratory studies found that one mask weighing between 3 and 4 grams can completely decompose into 880,000 to 1.17 million pieces of microplastic after nine days, while the damaged ones can decompose more quickly.

He said the figure could be underestimated because it can't imitate sunlight.

Meanwhile, a report by Hong Kong-based OceansAsia last year estimated that around 1.56 billion single-use surgical masks would enter the ocean by 2020. He estimated this could lead to the release of 1,370 trillion pieces of microplastic.

At a concentration of 10 microplastics per ml of water, Professor CityU said the total amount would pollute a volume of seawater equivalent to 54,800 Olympic-sized swimming pools. Meanwhile, he found about a third of the pieces were less than 10mm in size, while another 25 percent were larger than 50mm.

Ironically, these minuscule pieces of plastic can be eaten by microscopic crustaceans called copepods, which are found in almost every saltwater and freshwater habitat, providing food for larger animals including fish and even whales.

He tested its effects on one species, Tigriopus japonicus, and found their reproductive ability was reduced by 22 percent, while their nutrient intake and growth rate also slowed.

The researchers said they were concerned it could produce a domino effect on marine ecosystems, especially since masks are not the only source of microplastics in the oceans.

Microplastics from other waste, which can be in the form of drink bottles, cosmetics, clothing, and fishing nets, are already very difficult to remove from the environment.

If copepods are fed up with eating microplastics, they will eventually eat less algae, which causes red tides, the blooms of large aquatic plants that suffocate oxygen in the water and kill other animals.

Not only that, a reduction in the number of copepods due to slower reproduction could also mean a decrease in food sources for other species

"Since masks are a disease prevention tool, what we really need is stricter enforcement of rules to prevent littering," said Kenneth Leung Mei-yee, a professor who was also involved in the research.

In response to the SCMP, the Department of Environmental Protection said residents should not leave used face masks and "other useful items" unattended while in the countryside.

The department added that they used a drone system to monitor the city's 1,200-meter coast, which shortened the time needed to survey 65 beach locations in the Northern districts, Tai Po, Sai Kung, Sha Tin, Tuen Mun, as well as in the southern and island regions.