Table 2. Indoor Environmental Metrics Collected During Particle Count^a.

Variable	No. of patients	Mean (SD) [range]
Temperature, °C	76	24.1 (2.1) [18.6-28.2]
Humidity, %
Indoor	76	52.4 (8.3) [35.4-72.2]
Outdoor	79	65.5 (13.3) [35.0-96.0]
No. of particles
>0.5 μm/ft3 of air	79	316 138.5 (753 472.0) [114.4-5 300 000.0]
>5.0 μm/ft3 of air	79	876.9 (1352.8) [0-8843.3]
Mass concentration, μg/m3
PM2.5	83	2.6 (4.8) [0-5.5]
PM10	83	8.0 (9.9) [0-54.0]

Abbreviations: PM_2.5, particulate matter of 2.5 μm or less in aerodynamic diameter; PM₁₀, particulate matter of 10.0 μm or less in aerodynamic diameter.

^aMeasured using a handheld particle counter (Aerocet 531; MetOne Instruments, Inc).