Fig. 3.

(Left axis) Concentration of MS2 in the air at each sampling time point during the control and bipolar ionization (BPI) test experiments, averaged over each test set, where error bars represent standard deviation in each set of recoveries. (Right axis) Efficacy of the BPI device against aerosolized MS2, calculated as log₁₀ reduction in MS2 recoveries from the control vs. the BPI test experiments; statistical significance between control and technology experiments at the sample times is denoted by (*). For recoveries, error bars represent standard deviation in log₁₀ recoveries for each respective set of control and BPI experiments at each sample time; for efficacy, the error bars represent pooled standard error from both the control and technology experiments.