Impaired vascular function after exposure to diesel exhaust generated at urban transient running conditions

Table 1 Exposure characteristics of the present study during European Transient Cycle urban conditions compared to earlier studies [12, 14] during idling engine conditions.

	ETC urban present study	Idling previous study
*Exposure campaigns*
Diesel engine	Volvo TD40, 4.0 L, four cylinders	Volvo TD45, 4.5 L four cylinders
Diesel fuel	Diesel class I	Diesel class III
PM₁₀ mass concentration (filter), μg/m³	254 ± 36	330 ± 12 ⁽³⁾
PM₁₀ mass concentration (TEOM), μg/m³	228 ± 19	-
NO_x, ppm	7.5 ± 0.3	2.8 ± <0.1 ⁽³⁾
NO₂, ppm	0.9 ± 0.1	0.6 ± <0.1 ⁽³⁾
NO, ppm	6.6 ± 0.3	2.2 ± <0.1 ⁽³⁾
Total hydrocarbons (THC), ppm	1.2 ± 0.2	1.6 ± 0.2 ⁽³⁾
*Complementary measurements* ⁽¹⁾
Particle number concentration, #/cm³	1.2 × 10⁵	9.5 × 10⁵ ⁽⁴⁾
Particle count median size (CMD_mobility), nm	129	55 ⁽⁴⁾
Particle mass median size (MMD_aerodynamic) nm	116	199 ⁽⁴⁾
Organic carbon fraction (OC/TC⁽²⁾), %	12	94.5 ⁽⁴⁾
Elemental carbon fraction (EC/TC⁽²⁾), %	88	5.5 ⁽⁴⁾
Total PAH concentration, μg/m³	0.96	3.5 ⁽⁴⁾
Semi-volatile PAH concentration, μg/m³	0.69	3.4 ⁽⁴⁾
PM-associated PAH concentration, μg/m³	0.27	0.16 ⁽⁴⁾

⁽¹⁾ Particle number and PAH concentrations normalized to a PM mass concentration of 300 μg/m³ to enable a comparison between ETC and idling conditions.
⁽²⁾ TC = Total carbon content in PM mass
⁽³⁾ Exposure protocol data from a previously reported study [14]
⁽⁴⁾ Un-published DEP characteristics data associated with the exposure conditions during the previously reported studies [12, 14]
For the exposure campaign data, mean values are given mean ± std.dev.

ISSN: 1743-8977