Assessing the effectiveness of using various face coverings to mitigate the transport of airborne particles produced by coughing indoors

Figures & data

Figure 1. The time series of background-subtracted PNC at three locations, 0.3, 0.9, and 1.8 m away from the volunteer at condition #1 no face covering.

Table 1. Characteristics of the seven face covering conditions.

Face Covering Conditions	Pictures	Descriptions	Background-subtracted PNC at 0.3 m, #/cm^3 (mean ± standard error)	Percentage of Particle Reduction (%)
#1 No face covering	/	/	43 ± 7	/
#2 Face shield only		Silicone strap, clear polyester; size 31 cm ×26 cm	42 ± 10	4 ± 23%
#3 Cloth mask		2-ply, 100% cotton mask	7 ± 3	77 ± 7%
		3-ply, 50% cotton/50% polyester blend mask	12 ± 5
#4 Face shield  + Cloth mask		/	6 ± 2	89 ± 2%
			4 ± 1
#5 Surgical mask		Surgical masks from two manufacturers: 3-ply, pleated cellulose polyprolylene, polyester, adjustable nose clip	3 ± 2	94 ± 4%
#6 Face shield  + Surgical mask		/	3 ± 1	94 ± 2%
#7 N95 respirator or equivalent		N95 respirator: Ultrasonically welded headbands, adjustable nose clip, polyurethane nose foam, polypropylene filter, polyester shell and coverweb	2 ± 3	95 ± 2%
		KN95 mask: 5-ply, nonwoven fabric, hot air cotton and melt-blown fabric, elastic ear-loop, adjustable and invisible nose clip	2 ± 1

Figure 2. Background-subtracted PNCs at 0.3, 0.9, and 1.8 m away from the volunteer under #1 no face covering condition and #2-10 face coverings conditions. Error bars show the standard error of the mean. The Mann-Whitney U test was used to compare the PNC during coughing vs. background level. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.

Figure 3. Background-subtracted particle size distributions of cough-generated airborne particles under different face covering conditions at 0.3, 0.9, and 1.8 m away from the volunteer. Error bars show the standard error of the mean. Please note different scale on Y-axis.