Disposable masks are a plastic product that does not biodegrade easily and can break down into smaller plastic particles, microplastics and nanoplastics that are widely found in ecosystems.
Disposable masks are produced on a scale similar to plastic bottles, estimated at 43 billion a month.
However, unlike plastic bottles (about 25 percent of which are recycled), there are no official guidelines for the recycling of masks, making them more likely to be treated as solid waste, the researchers wrote.