148 Development of a test Method to Determine Inhalation Exposure of Microplastic Particles when Reusable Disposable Masks in Place

Abstract Situation/broad aims The SARS-CoV-2 pandemic has swept the globe since late 2019 and has driven explosive growth in the use of masks that has arisen an emerging concern of inhaled microplastic particles (MPs) when reuse disposable masks. In this study, we proposed a new methodology to determine whether the inhaled particles of microplastics emitted from the disposable masks when reusable mask in place as source control. Methods All experiments were conducted using a head-form manikin with a constant inspiratory flow at a simulated chamber. One commercially available ASTM Level 1 face (or surgical) mask with three-layer material, namely polypropylene (outer and middle layers), and polyethylene (inner layer) was used as test specimen to characterize the inhalation exposure of MPs. Brand new and reusable masks with and without a hand rubbing were compared. Particle physical characterization and morphology were determined using fluorescent staining with Nile red dye and scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) as well. The multiple-path particle dosimetry model was utilized to calculate the particle deposition in the respiratory tracts of human adults for emitted MPs fallen within the micrometer size range. Outcomes of the work: In this study, we proposed a method that the incorporation of scanning electron microscopy and infrared spectroscopy into the current fluorescent staining method to enhance the detection of MPs for qualitative analysis, may be more predictive of fragment microplastics are sourced from the different layer of disposable mask with a hand rubbing when in use.