This month marks the anniversary of San Francisco implementing the first face mask mandate in the United States. Since then, nearly all states have implemented mask mandates during the COVID-19 pandemic. By October, 93% of Americans said they sometimes, often, or always wear a mask or face covering when they leave their home and are unable to socially distance.

"Humanity is going through 129 billion face masks a month, which works out to three million a minute," according to Big Think.

With large populations of the world using masks regularly as a health precaution against coronavirus, it has had an unintended consequence – pollution.

The Ocean Conservancy released new data detailing how personal protective equipment has polluted beaches and oceans all over the planet. Volunteers who were cleaning beaches all over the world tracked the number of PPE they found on the shore. From late July until December 2020, volunteers collected 107,219 items of personal protective equipment from beaches and waterways worldwide.

The Ocean Conservancy notes that the number is "likely a vast undercount of what was and remains out there" because many volunteers recorded discarded PPE as "Personal Hygiene" or "Other Trash."

"The amount of personal hygiene litter recorded in the app between January and July 2020 was three times higher than what was recorded in that same time period for each of the previous three years despite significantly lower participation levels due to the pandemic lockdowns."

The report found that 94% of the volunteers encountered PPE pollution during their cleanup efforts, and over 80% of respondents identified face masks as the most common waste PPE. There were 37% of cleanup participants who reported PPE in waterways.

"This is the first time we have some very hard evidence to shed a spotlight on the magnitude of the PPE component of the plastic pollution issue, and really underscores how this is a new additive component to our existing global crisis," Nick Mallos, senior director for the group's Trash Free Seas program, told KING-TV.

"This was not a typical type of litter that we saw more than a year ago," said Amber Smith, litter prevention coordinator for the Washington Department of Ecology. "This is a brand-new thing related to COVID, and it's really concerning."

Volunteers with New Jersey's Clean Ocean Action environmental group removed 1,113 masks and other pieces of coronavirus-related protective gear from New Jersey beaches last fall.

A report from OceansAsia from last year estimated nearly 1.6 billion face masks flooded the oceans in 2020. The group suspects that discarded face masks would result in an additional 4,680 to 6,240 metric tons of marine plastic pollution. The Hong Kong-based marine conservation organization claims that the face masks would take as long as 450 years to break down.

"Most of these face mask wastes contains either polypropylene and/or polyethylene, polyurethane, polystyrene, polycarbonate, polyacrylonitrile, which add plastic or microplastic pollution to the environment," ScienceDirect reports.

Single-use face masks are believed to be a source of microplastic pollution, which could pose health risks to humans.

"A newer and bigger concern is that the masks are directly made from microsized plastic fibers (thickness of ~1 to 10 micrometers)," according to a study by doctors Elvis Genbo Xu of the University of Southern Denmark and Zhiyong Jason Ren of Princeton. "When breaking down in the environment, the mask may release more micro-sized plastics, easier and faster than bulk plastics like plastic bags. Such impacts can be worsened by a new-generation mask, nanomasks, which directly use nano-sized plastic fibers (with a diameter smaller than 1 micrometer) and add a new source of nanoplastic pollution."

"Single-use polymeric materials have been identified as a significant source of plastics and plastic particle pollution in the environment," another study claimed. "Disposable face masks (single use) that get to the environment (disposal in landfill, dumpsites, freshwater, oceans or littering at public spaces) could be emerging new source of microplastic fibers, as they can degrade/fragment or break down into smaller size/pieces of particles under 5 mm known as microplastics under environmental conditions."

"Obviously, PPE is critical right now, but we know that with increased amounts of plastic and a lot of this stuff getting out into the ocean, it can be a really big threat to marine mammals and all marine life," said Adam Ratner, an educator at the Marine Mammal Center, a conservation group that rescues and rehabilitates mammals.

"It is noted that face masks are easily ingested by higher organisms, such as fishes, and microorganisms in the aquatic life which will affect the food chain and finally chronic health problems to humans," one study noted.

"Researchers believe masks could compound that issue, as the spun plastic fibers break down into smaller and smaller particles that evade filters," KING-TV reported. "Small fibers and particles are widely found in drinking water, and such contamination can bio-accumulate in marine life, causing problems for the creatures themselves, and those higher up the food chain that consume them."

A 2019 report by Australia's University of Newcastle found that the largest source of plastic ingestion by humans were drinking water and eating shellfish.

"Plastic pollution is so widespread in the environment that you may be ingesting five grams a week, the equivalent of eating a credit card," Reuters reported.

"Because research into microplastics is so new, there's not yet enough data to say exactly how they're affecting human health, says Jodi Flaws, a professor of comparative biosciences and associate director of the Interdisciplinary Environmental Toxicology Program at the University of Illinois," a 2019 report from the Washington Post. "Flaws says microplastic particles can also accumulate polychlorinated biphenyls (PCBs), other chemicals that are linked to harmful health effects, including various cancers, a weakened immune system, reproductive problems and more."

The article warns that microplastics can disrupt hormones and reduce fertility.

Another issue is that disposable masks can't be recycled with typical recyclables, which makes disposing of PPE even more challenging.

"Used correctly PPE saves lives; disposed of incorrectly it kills marine life," said Cindy Zipf, the executive director of New Jersey's Clean Ocean Action. "PPE litter is a gross result of the pandemic, and 100% avoidable. Use PPE properly, then dispose of it properly in a trash can. It's not hard and it's the least we can do for this marvel of a planet we all live on, not to mention ourselves."