Table 1.

Aerosol generating procedures and the effects of the personal ventilation hood

	SMPS* data: particle counts (particles/mL)		APS† data: particle counts (particles/mL)
	No hood Mean (25–75%)	Hood Mean (25–75%)	No hood Mean (25–75%)	Hood Mean (25–75%)
Breathing	0.0	0.2	0.03	0.02
	(–0.5 to 0.3)	(–0.2 to 0.7)	(0.01–0.04)	(0.01–0.03)
Talking	–0.6	0.0	0.04	0.01
	(–0.9 to –0.4)	(–0.1 to 0.2)	(0.02–0.05)	(0.01–0.02)
Wet cough	0.6	0.2	0.18	0.02
	(0.6–0.8)	(–0.0 to 0.2)	(0.11–0.25)	(0.02–0.03)
Dry face mask	11.2	–0.10	0.18	–0.02
	(8.7–14.9)	(–2.5 to 2.3)	(0.10–0.20)	(–0.03 to –0.01)
60 L/min (nasal, humidified)	13.2	6.8	0.24	0.03
	(10.0–17.8)	(6.1–8.5)	(0.21–0.25)	(0.01–0.05)
BiPAP (humidified)	630	11.8	29.7	0.51
	(520–690)	(9.6–18.3)	(25.7–35.2)	(0.45–0.59)
Nebuliser	51 000	570	1080	8.9
	(43 000–54 000)	(500–700)	(880–1200)	(6.6–11.6)

APS = Aerodynamic Particle Sizer spectrometer; BiPAP = bilevel non-invasive positive-pressure; SMPS = scanning mobility particle sizer spectrometer.

^*TSI SMPS 3080.

^†TSI APS 3220.