Table 1.

Exhaled droplet concentrations (particles/cm³) for different size ranges during different expiratory activities reported by Morawska et al. (2009).

Expiratory activity	D1 (0.80 μm)	D2 (1.80 μm)	D3 (3.5 μm)	D4 (5.5 μm)
Whispered counting	0.236	0.068	0.007	0.011
Voiced counting	0.110	0.014	0.004	0.002
Speaking	0.751	0.139	0.139	0.059
Breathing	0.084	0.009	0.003	0.002