To truly prevent inhalation exposure, a tight fitting half mask respirator with P100 cartridges is the first step. Powered air purifying respirators with a P100 would probably be a better choice because they are easier to fit and breathe with for extended periods. On a larger, public scale, improving ventilation in a given space to better clear aerosolized virus is the best solution. We saw no workplace cases where the ventilation was giving us a few air changes per hour and using 100% outdoor makeup air.