Figure 3
Temporal variability of atmospheric aerosol properties relevant for the pro-inflammatory and oxidative endpoints. The 10-min time series of the number concentration of nanoparticles (N\(_{8-20}\)) is indicated on the left primary y-axis. Data points are colored by the condensation sink of accumulation mode particles (CS\(_{200-800}\)). The 24-h data for HMOX-1 (black line) and CXCL-8 (grey line) f.c. gene expression is indicated on the secondary right y axes. The 24-h data of the aerosol oxidative potential (DTT activity in PM\(_1\) quartz samples) is indicated (dotted black line) on the secondary right y-axis. The 2-h data of particle-bound ROS (as PM1 mass-normalized values) is displayed on the secondary left axis (dotted red line). The 24-h values of PM2.5 mass concentration (\(\upmu g \cdot m^{-3}\)) measured by the local environmental agency are indicated at the top of the plots. Note the parallel gene up-regulation on: Jan 26 (HMOX-1 f.c.=3.51±0.18 with \(p<\)0.01, CXCL-8 f.c.=1.18±0.08 but \(p>\) 0.05); Feb 16 (HMOX-1 f.c.=3.00±0.10 with \(p<\) 0.01, CXCL-8 f.c.=1.47±0.15 with \(p<\)0.05); Jan 28 (HMOX-1 f.c.=1.78±0.05 with \(p<\) 0.01, CXCL-8 f.c.=1.09±0.01 with \(p<\)0.01); Feb 04 (HMOX-1 f.c.=1.30±0.06 with \(p<\) 0.01, CXCL-8 f.c.=1.20±0.03 with \(p<\) 0.01). On Feb 03, there is data missing: (i) from h 09:06 to h 12:45 cells’ exposure was discontinued due to the activation of a diesel generator, and the line is thinner; (ii) from h 15:00 to 20:00 the OA data is missing and the marker color is grey.
