Aerosol particles (0.3–10 μm) inside an educational workshop−Emission rate and inhaled deposited dose

Publication date: August 2018
Source:Building and Environment, Volume 140
Author(s): Androniki Maragkidou, Omar Jaghbeir, Kaarle Hämeri, Tareq Hussein
In this study, we measured the concentrations of accumulation and coarse particles inside an educational workshop (March 31–April 6, 2015), calculated particle emission and losses rates, and estimated inhaled deposited dose. We used an Optical Particle Sizer (TSI OPS 3330) that measures the particle number size distribution (diameter 0.3–10 μm) and we converted that into particle mass size distribution (assuming spherical particles and unit density). We focused on two particle size fractions: 0.3–1 μm (referred as PN0.3−1 and PM0.3−1) and 1–10 μm (referred as PN1−10 and PM1−10). The occupants' activities included coffee brewing, lecturing, tobacco smoking, welding, scrubbing, and sorting/drilling iron. The highest concentrations were observed during welding with PN0.3−1 (PM0.3−1) was ∼1866 cm⁻³ (55 μg/m³) and PN1−10 (PM1−10) was ∼7 cm⁻³ (103 μg/m³). The lowest concentrations were observed during coffee brewing and metal turning with PN0.3−1 (PM0.3−1) was ∼22 cm⁻³ (0.7 μg/m³) and PN1−10 (PM1−10) was ∼0.5 cm⁻³ (4 μg/m³). The emissions rate of coarse particles was 85–1010 particles/hour × cm³ whereas that for submicron particle in the diameter range 0.3–1 μm was 5.7 × 10⁴–9.3 × 10⁴ particles/hour × cm³ depending on the activity and the ventilation rate. The coarse particles losses rate was 0.35–2.1 h⁻¹ and the ventilation rate was 0.24–2.1 h⁻¹. The alveolar received the majority and particles below 1 μm with a fraction of about 53% of the total inhaled deposited dose whereas the head/throat region received about 18%. This study is important for better understanding the health effects at educational workshops.

Graphical abstract