The COVID-19 pandemic has been a worldwide issue for over a year now, and transit agencies are still struggling to find cost efficient solutions, which will provide improved rider safety and restore rider confidence. Airborne transmission of the virus has been identified as one of the primary modes through which COVID-19 is spread. MERV 13 filters are able to filter 85% of particles from 1 µm to 3 µm in size, which is ideal for capturing the respiratory droplets. MERV 8+Ag filters contain a silver impregnated layer within and on top of the filter material. This silver layer has antiviral properties which can deactivate viruses trapped within the layer, as well as help prevent the growth of other pathogens that may have been trapped on the filter and will sit on the used filter until it is replaced. The primary goal of this study is to determine if the performance on these filters change over time, specifically in the transit environment, and to compare the results to manufacturer ratings.

The intended outcome of the project is to provide a series of guidance and recommendations to transit agencies to help them decide whether it is worth the additional financial cost as well as any potential increased maintenance associated with upgrading their filters.