Princeton University, and Elvis Xu, an environmental scientist from the Based on recent studies, the authors estimated that some 129 billion single-use face masks are used per month worldwide. This figure corresponds to three million masks used per minute. Most of these masks are made from plastic microfibers, typically ranging in size from five millimeters (mm) to microscopic lengths. There have been increasing reports as well of the inappropriate disposal of soiled face masks. The authors said it is urgent to recognize single-use face masks as a potential environmental threat to prevent them from becoming the next big plastic problem. Face masks could be worse than plastic bottles