Exudation of microplastics from commonly used face masks in COVID-19 pandemic

Abstract

The COVID-19 pandemic forced use of face masks up to billions of masks per day globally. Though an important and necessary measure for control of the pandemic, use of masks also poses some inherent risks. One of those risks is inhalation of microplastics released from the mask materials. Since most of the mask materials are made from plastic/polymers, they always have the potential to expose the user to fragmented microplastics. To estimate the amount of inhalable microplastic exuded from masks, an experiment simulating real-life scenario of mask usage was performed. The study included collection of microplastics oozed out from the masks on to a filter paper followed by staining and fluorescence detection of the total number of microplastics using a microscope. Both used and new masks were studied. Based on the emission wavelength, the microplastics were found to be belonging to three different categories, namely blue, green and red emitting microplastics respectively. The number of microplastic particles emitted per mask over a period of usage of 8 h was about 5000 to 9000 for new masks and about 6500 to 15,000 for used masks respectively. The estimation of polymer type of plastic in the mask fabrics was also carried out using Raman and FTIR spectroscopy.

Keywords: COVID-19; Face mask; Fluorescence microscopy; Inhalable MPs; Microplastics.

Fig. 1

Setup for collection of microplastics emitted from masks

Fig. 2

Sample images of microplastics under fluorescence microscope (combined image of all three filters)

Fig. 3

Sample Raman spectra of surgical and N95 masks in both high- and low-frequency ranges

Fig. 4

Sample FTIR spectra of cloth, surgical and N95 masks

Fig. 5

Percentage distribution of green, blue and red emitting MPs in different types of masks

Fig. 6

The percentage change in number of MPs emitted from new and used masks