Fraction of BaP remaining in an 8-nm-thick cooking oil film exposed to different gas-phase ozone mixing ratios after 1 h (black), 12 h (purple), 1 d (blue), and 1 wk (red) at 295 K and dry conditions, as simulated by KM-SUB considering phase separ... Fraction of BaP remaining in an 8-nm-thick cooking oil film exposed to different gas-phase ozone mixing ratios after 1 h (black), 12 h (purple), 1 d (blue), and 1 wk (red) at 295 K and dry conditions, as simulated by KM-SUB considering phase separation and crust formation by BaP oxidation products (solid lines) or assuming ideal mixing (dashed lines). Shouming Zhou et al. PNAS 2019;116:24:11658-11663 ©2019 by National Academy of Sciences