Simulations of centennial PAH mobility in the presence of DOM were performed for a background contaminated Spodosol in NE Bavaria, Germany using a numerical code. Additional to stationary and instationary PAH input, DOM concentrations were allowed to vary on different time-scales. This imposes a time- and depth dependence on the ratio of DOM-associated and free PAH and thereby alters total PAH sorption. The impact of DOM-fluctuations on PAH-mobility shows to be strongly affected by the time-scale of variations.