While federal mask mandates during the coronavirus pandemic were designed to protect the public and reduce the spread of COVID-19, they had another unintended outcome, too: all those used masks piling up as litter. That's according to a new research study published in the online monthly journal Nature Sustainability.
Mask litter was nearly nonexistent before the COVID-19 pandemic ushered in universal masking for everyone, and not just among medical, construction or other professionals.
"As soon as masks were recommended or mandates came out, mask litter started to appear," said Keiron Roberts, a professor of sustainability at the University of Portsmouth in England and lead author of the study. "It's really stating the obvious. If you are telling people to use a mask for the first time, it will appear in litter."
The researchers relied on citizen-powered litter-collection apps, including Litterati, to analyze changes in the volume of mask and other PPE litter from September 2019 to October 2020 across 11 countries.
They used keywords including "mask," "glove" and "wipe" to track the number of pieces of each type of litter collected each month.
Researchers then overlaid information on mask mandates and other worldwide restrictions onto the litter data and found a correlation between mask rules and the volume of facial coverings showing up on streets.
"Before mandates, there was very little mask litter. A month onwards is when you see this increase," they reported. "It's essentially a strong indicator that mandating any item will result in its occurrence in litter, which supports the notion of if you start a mandate for something, also support its removal treatment."
80-fold increase in mask litter
The proportion of masks in litter increased more than 80-fold as a result of COVID-19 legislation, or from less then 0.01% to more than 0.8%, according to the study.
Glove usage, widely adopted before much was known about how COVID-19 spreads, resulted in an uptick in litter early on during the pandemic. But discarded gloves quickly disappeared from streets after hand-washing was recommended over glove-wearing.
"Glove litter occurred before mandates occurred — people wore gloves when they thought the virus was spread through touch. When education came out not to wear gloves but to wash one's hands, they started to disappear," Roberts said.
In his opinion, local governments that imposed mask mandates did not do enough to educate the public on mask disposal.
"People in shops were wearing mask and then they go outside and there wasn't a bin available, so they'll put it in a pocket and it will fall out later, or people scrunch it up and throw it on the floor," Roberts said. "If you start legislating the use of these things, you need to support businesses in getting rid of it."
The researchers don't suggest that mask mandates themselves are misguided. "We need to use these items but we also need to educate people so they can do the right thing afterwards, which is putting it in the washing machine if it's a multi-use one or in the bin if it's single use," Roberts said.
Harmful toll on animals, environment
So, how bad is mask litter for the environment? For one, disposable surgical masks, with their ear loops, can easily choke and strangle animals that get tangled up in them. They can also smother the ground, and limit the plant-life growth that's beneath them when they're not removed, according to Roberts. When masks enter drains they can cause blockages and break down into smaller pieces that can be ingested, too.
The ultimate environmental toll occurs when masks turn into microplastics that are smaller than 5 millimeters in length and can harm aquatic life.
"We are only starting to scratch the surface of what these do in the environment," Roberts said. "Let's make sure this litter fingerprint we've got in nature is gone so we're not digging up gardens in years to come and finding masks."
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