Microplastics in humans: Scientists find traces in the lungs for the first time
https://www.medicalnewstoday.com/articles/323428#Salt-of-the-earth
The material most commonly used to make these masks is polypropylene—a type of fabric made from a “thermoplastic” polymer (meaning that it’s easy to work with and shape at high temperatures). Blue surgical masks can also be made of polystyrene, polycarbonate, polyethylene, or polyester— all of which are types of fabrics derived from thermoplastic polymers.
https://health-desk.org/articles/what-are-blue-surgical-masks-made-of-and-is-the-material-safe