Fig. 1. Oxy-PAHs induce a time- and dose-dependent increase of cellular EROD activity. HaCaT cells were exposed to 0.1, 1.0 or 10 μM oxy-PAH or B[a]P and CYP1-dependent EROD activity was measured at 3, 6, 24 and 48 h after exposure. Data points represent means ± SE, n = 3. *p < 0.05 as compared with DMSO control by two-way ANOVA.