II suppose it was pretty much inevitable that when a few billion disposable masks were distributed around the world in response to the pandemic, they would become a garbage problem, too.
The first report I saw on this subject was called "Masks on the Beach: The Impact of COVID-19 on Marine Plastic Pollution," by Teale Phelps Bondaroff and Sam Cooke from a marine conservation nonprofit called OceansAsia (December 2020). They write:
The number of masks entering the environment on a monthly basis as a result of the COVID-19 pandemic is staggering. From a global production projection of 52 billion masks for 2020, we estimate that 1.56 billion masks will enter our oceans in 2020, amounting to between 4,680 and 6,240 metric tonnes of plastic pollution. These masks will take as long as 450 years to break down and all the while serve as a source of micro plastic and negatively impact marine wildlife and ecosystems.Of course, the plastic in masks (and latex gloves and other personal protection equipment) is only a small proportion of overall plastic waste ending up in oceans.
Plastic production has been steadily increasing, such that in 2018, more than 359 million metric tonnes was produced. Estimates suggest that 3% of this plastic enters our oceans annually, amounting to between 8 to 12 million metric tonnes a year. This plastic does not ‘go away,’ but rather accumulates, breaking up into smaller and smaller pieces. Annually, it is estimated that marine plastic pollution kills 100,000 marine mammals and turtles, over a million seabirds, and even greater numbers of fish, invertebrates, and other marine life. Plastic pollution also profoundly impacts coastal communities, fisheries, and economies. Conservative estimates suggest that it could cost the global economy $13Articles in academic journals are now beginning to emerge that echo this point. For example, Elvis Genbo Xu and Zhiyong Jason Ren have written "Preventing masks from becoming the next plastic problem" in Frontiers of Environmental Science & Engineering (February 28, 2021, vol. 15, article #125). They write (citations omitted):
billion USD per year, and lead to a 1-5% decline in ecosystem services, at a value of between $500 to $2,500 billion USD.
Face masks help prevent the spread of coronavirus and other diseases, and mass masking is recommended by almost all health groups and countries to control the COVID-19 pandemic. Recent studies estimated an astounding 129 billion face masks being used globally every month (3 million / minute) and most are disposable face masks made from plastic microfibers. ... This puts disposable masks on a similar scale as plastic bottles, which is estimated to be 43 billion per month. However, different from plastic bottles, ~ 25% of which is recycled, there is no official guidance on mask recycle, making it more likely to be disposed of as solid waste. ... It is imperative to launch coordinated efforts from environmental scientists, medical agencies, and solid waste managing organizations, and the general public to minimize the negative impacts of disposal mask, and eventually prevent it from becoming another too-big-to-handle problem.
As another example, Auke-Florian Hiemstra, Liselotte Rambonnet, Barbara Gravendeel, and Menno Schilthuizen write about "The effects of COVID-19 litter on animal life" in Animal Biology (advance publication on March 22, 2021). They write (again, citations omitted):
To protect humans against this virus, personal protective equipment (PPE) is being used more frequently. China, for example, increased face mask production by 450% in just one month. It is estimated that we have a monthly use of 129 billion face masks and 65 billion gloves globally. Similar to the usage of other single-use plastic items, this also means an increase of PPE littering our environment. PPE litter, also referred to as COVID-19 litter, mainly consists of single-use (usually latex) gloves and single-use face masks, consisting of rubber strings and mostly polypropylene fabric. Three months after face masks became obligatory in the UK, PPE items were found on 30% of the monitored beaches and at 69% of inland clean-ups by the citizen scientists of the Great British Beach Clean. Even on the uninhabited Soko Islands, Hong Kong, already 70 discarded face masks were found on just a 100-meter stretch of beach. A growing public concern about PPE litter became apparent during March and April 2020, as a Google News search on ‘PPE’ and ‘litter’ showed a sudden increase in news articles. As a response to the increase of COVID-19 litter, many states in the USA have raised the fines for littering PPE, sometimes up to $5500 as in Massachusetts. ... While the percentage of COVID-19-related litter may be small in comparison with packaging litter ... [b]oth masks and gloves pose a risk of entanglement, entrapment and ingestion, which are some of the main environmental impacts of plastic
It is striking that all the reported findings of entanglement, entrapment, ingestion, and incorporation of PPE into nests so far involved single-use products. Switching to reusables will result in a 95% reduction in waste ... To minimize the amount of COVID-19 litter and its effect on nature, we urge that, when possible, reusable alternatives are used.
I'll spare you the pictures of fish and wildlife tangled up in plastic masks and gloves, and just say it in words. Wearing a mask when in proximity to others was a reasonable step to take during this past year (as discussed here and here). But disposing of masks properly matters, too.