Road tunnel-derived coarse, fine and ultrafine particulate matter: physical and chemical characterization and pro-inflammatory responses in human bronchial epithelial cells

Table 1 The hydrodynamic size distributions of road tunnel PM samples

Sample name (PM)	Size fraction	Sampled PM (mg/m³/h)	Median hydrodynamic size by mass (μm)	Median hydrodynamic size by number (μm)
Marienborg, dry conditions	Coarse (2.5–10 μm)	0.07	1.98	0.07
	Fine (0.18–2.5 μm)	0.05	1.50	0.07
	Ultrafine (< 0.180 μm)	0.03	1.72	0.07
Marienborg, humid conditions	Coarse (2.5–10 μm)	0.11	1.67	0.08
	Fine (0.18–2.5 μm)	0.05	1.52	0.08
	Ultrafine (< 0.180 μm)	0.05	1.15	0.07
Hell, dry conditions	Coarse (2.5–10 μm)	2.42	3.01	0.05
	Fine (0.18–2.5 μm)	0.49	1.56	0.06
	Ultrafine (< 0.180 μm)	0.50	2.22	0.07
Hell, humid conditions	Coarse (2.5–10 μm)	0.16	2.48	0.11
	Fine (0.18–2.5 μm)	0.06	2.07	0.08
	Ultrafine (< 0.180 μm)	0.04	0.79	0.07
Marienborg, after cleaning humid conditions	Coarse (2.5–10 μm)	0.18	2.22	0.06
	Fine (0.18–2.5 μm)	0.06	1.33	0.08
	Ultrafine (< 0.180 μm)	0.02	1.04	0.07
Hell, after cleaning dry conditions	Coarse (2.5–10 μm)	3.01	3.11	1.07
	Fine (0.18–2.5 μm)	0.66	1.49	0.08
	Ultrafine (< 0.180 μm)	0.46	1.44	0.07

Coarse, fine and ultrafine PM were sampled in two road tunnels (Marienborg and Hell) by a High-volume cascade impactor during dry and humid road surface conditions, respectively, and also after road surface cleaning. The amounts of the coarse, fine and ultrafine PM were weighed, and presented as mg PM/m³/h. The table also includes hydrodynamic size distributions as determined by the Disc centrifugation method and presented as median size related to PM mass and also to particle number

ISSN: 1743-8977