Fig 3. Changes in walker numbers and environmental factors (dust particle numbers) in the underground pedestrian space.
(A) Changes in walker numbers. (B) Changes in particle numbers (particle size Δ0.5: 0.3–0.5μm). (C) Changes in numbers of particles (particle size Δ1.0: 0.5–1.0μm). (D) Changes in numbers of particles (particle size Δ5.0: 1.0–5.0μm). Left and right panels show daily and monthly changes, respectively. Asterisks indicate a significant difference (p<0.05) between bars connected by lines.