Table 3 Comparison of respiratory particle concentrations and/or emission rates with previous studies (for speaking activities only).
From: Respiratory particle emission rates from children during speaking
Author | Respiratory activity | Participants | Particle concentration or emission rate |
|---|---|---|---|
This study | Speaking, i.e., reading a text at normal and higher intensity level | 371 children | Concentrations: ∙ Speaking = 0.11–0.94 particles cm−3 (median 0.30 particles cm−3) ∙ Loudly speaking = 0.15–1.37 particles cm−3 (0.43 particles cm−3) Emission rates: ∙ Speaking = 7.1–92.5 particles s−1 (median 25.6 particles s−1) ∙ Loudly speaking = 10.4–146.2 particles s−1 (median 40.6 particles s−1) |
Mürbe et al.22 | Speaking, i.e., reading a text | 8 adolescents | Emission rate: 16–267 particles s−1 (median 80 particles s−1) |
Ahmed et al.25 | Phonation (specific frequencies and different vocal intensity levels) | 40 adults | Emission rate: 2.1–22 particles s−1 (median 9.1 particles s−1) |
Bagheri et al.17 | Speaking, i.e., reading a text at normal and higher intensity level | 132 subjects including 21 children aged 5–9 years old and 24 children aged 10–14 years | Concentrations: ∙ Speaking 5–9 years = geometric mean ± deviation 0.041 ± 1.654 particles cm−3 ∙ Speaking 10–14 years = geometric mean ± deviation 0.077 ± 2.324 particles cm−3 ∙ Loudly speaking 5–9 years = geometric mean ± deviation 0.072 ± 1.859 particles cm−3 ∙ Loudly speaking 10–14 years = geometric mean ± deviation 0.120 ± 2.187 particles cm−3 Concentration increases with age (e.g., adults) |
Asadi et al.33 | Speaking, i.e., reading a text | 48 adults | Concentrations: 0.06–3 particles cm−3 Emission rates: 1–50 particles s−1 |
Archer et al.27 | Speaking at a controlled sound pressure level | Adolescents aged 12–14 years and adults aged19-72 years | Concentrations: ∙ Adolescents = 0.10–0.36 particles cm−3 (median 0.21 particles cm−3) ∙ Adults = 0.02–1.70 particles cm−3 (median 0.18 particles cm−3) Emission rates: ∙ Adolescents = 19.7–74.5 particles s−1 (median 40.7 particles s−1) ∙ Adults = 11.4–306 particles s−1 (median 60.1 particles s−1) |
Fleischer et al.23 | Speaking, i.e., reading a text | 15 children aged 8–10 years | Emission rates: 8–86 particles s−1 (median 24 particles s−1) |
Morawska et al.32 | Speaking, i.e., voiced counting | 15 adults | Concentrations: median 0.3 particles cm−3 |
Gregson et al.24 | Speaking at different volumes | 25 adults | Concentrations: 0.016–3.7 particles cm−3 (median, at 70–80 dB, 0.22 particles cm−3) |
