Release kinetics of microplastics from disposable face masks into the aqueous environment.

Abstract Disposable face masks are widely used as primary personal protective equipment to control the spread of the SARS-CoV-2 virus. Disposable face masks have been identified as a source of microplastics and a new threat to the environment when improperly handled. To understand the release of microplastics from discarded masks into water, the release quantities of microplastics from three types of disposable face masks (N95, medical surgical, and normal medical masks) were measured within 24 h and their release kinetics were analyzed over seven days. Results showed that polypropylene microplastics fibers and debris of various colors were released. N95 masks released 801 ± 71–2667 ± 97 microplastic particles/(piece·d), medical surgical masks released 1136 ± 87–2343 ± 168 microplastic particles/(piece·d), and normal medical masks released 1034 ± 119–2547 ± 185 microplastic particles/(piece·d), irrespective of the price, weight, or type of mask. The microplastics were first released fast and then slow. The Elovich equation described the release kinetics (R2 > 0.990), and the release rate did not differ with the type of mask. Microplastics of 100–500 μm and of