Figure 5
CYP1A1 activity of human nasal epithelial cells exposed for 24 hrs to 10 μg/cm2 of the different size-fractions (UF: PM 0.03–0.17 , F: PM 0.17–1 , I: PM 1–2.5 and C: PM 2.5–10 ) of winter and summer aerosol samplings. The CYP 1A1 activity was measured for 40 min and the kinetic slope was determined. Kinetic slopes of four size-segregated aerosol samplings in winter and three size-segregated aerosol samplings in summer were pooled and presented as box plots. Each box plot is composed of 3 horizontal lines displaying the 25th, 50th and 75th percentiles. Minimal and maximal values are plotted as a dot. n = 8. * different from control (p < 0.05), ° different between seasons within a size-fraction (p < 0.001), different letters indicate significant difference between size-fractions within each season (p < 0.001).