Fig 5. Background-corrected particle counts comparing Front and vulnerable positions for each facemask at a one-foot (0.3 m) distance in the open bench environment.

Measurements shown are grouped by particle size bin and colored by measurement position. Row 1 includes particle counts for the Front position of each facemask. Row 2 includes vulnerable positions deemed significant during experimental observation. Vulnerable positions include: Side (Surgical mask), Bottom (N95L), and Top (sewn masks, N95T). Gray bullet points at the baseline indicate negative background-corrected counts. Error bars indicate the sample standard deviation for particle counts in each of the respective particle size bins from three independent measurements. For statistical analyses, refer to the open bench analysis described in Fig 4.