Disposable face masks can take more than 450 years to break down.

As 2020 draws to a close, one of the most recognizable symbols of the year may be the protective face mask.

As the novel coronavirus swept across the globe earlier this year, billions of people began wearing the face coverings, with one study estimating that no less than 129 billion face masks were being used every month around the world.

However, as face masks have become ubiquitous in our day-to-day lives, they’ve also grown to litter every corner of our neighborhoods, from storm drains to creeks, parks to beaches.

And now, it turns out that our oceans are swimming with face masks, according to a new report from marine conservation NGO OceansAsia.

“Once plastic enters the marine environment, it’s very difficult to move,” Dr. Teale Phelps Bondaroff, the group’s director of research, told Denver 7.

“The fact that we are starting to find masks that are breaking up indicates that this is a real problem, that microplastics are being produced by masks,” Bondaroff said.

The Hong Kong-based group estimates that some 1.56 billion face masks will have flooded our oceans in 2020 alone – a grim statistic that they have witnessed firsthand since face masks began washing up on a small island off the coast of the Chinese mega-city since the start of the pandemic.

The masks could become yet another major contributor to the ongoing crisis of plastic pollution in our ocean, with disposable face masks taking as long as 450 years to break down.

The single-use masks that are recommended by health authorities and used as personal protective equipment in hospitals across the world are made of multiple layers of polypropylene, which are thin fibers of plastic.

And with 52 billion masks being manufactured in this year, with the average weight of each single-use polypropylene surgical face mask being 3 to 4 grams, we could be looking at anywhere from 4,680 to 6,240 metric tons of new marine plastic pollution.

Ocean pollution has already reached such monstrous proportions that an estimated 100 million tons of plastic can now be found in the world’s oceans, according to the United Nations. Between 80 and 90 percent of it comes from land-based sources. And according to a report prepared for the 2016 World Economic Forum in Davos, Switzerland, by 2050 it is estimated that plastic waste in the ocean will outweigh all fish.

In recent years, ocean biologists and conservationists have expressed alarm over the growing problem of plastics and microplastics inundating the world’s oceans and water supplies, leaching carcinogenic toxins and chemicals into the marine environment, with plastic drink containers trapping and confining — and ultimately killing — marine wildlife.

“The question that we couldn’t answer was how many [masks] are entering our oceans? We just didn’t know,” Dr. Bondaroff said.

OceansAsia’s recent study could offer some alarming clues as to the extent of the pollution, however.

“The 1.56 billion face masks that have entered our oceans in 2020 are there for the long run,” he said. “They will remain in the ocean for 450 years or more, and they’ll break into smaller pieces.”

The report notes that the global sales force of face masks has grown exponentially, increasing from $800 million in 2019 to $166 billion in 2020.

The surging sales come as health authorities like the Centers for Disease Control and Prevention have issued official health guidance urging U.S. residents to always wear a face mask in public in lieu of or in addition to physical distancing measures meant to help prevent person-to-person transmission of the deadly disease.

“That’s important, we need to keep people safe, but at the same time that has a lasting impact on our environment, and we’re seeing that on the beaches,” Bondaroff added.

The report requests that the public wear reusable masks when possible while also disposing of masks properly as a step toward drawing down overall consumption of single-use plastics.

The group also calls on authorities to encourage the use of reusable masks, including releasing guidelines on the proper manufacture and use of reusable masks, while also educating the public about responsibly disposing of masks, among other measures.