A study conducted by the UPV/EHU's IBeA group shows that pyroclasts may be putting the conservation of the paintings of Pompeii at risk. Specifically, the ions leached from these materials and the underground ion-rich waters from the volcanic rocks may be causing the salts in the paintings to crystallize. In addition, the use of fluorine as a marker is proposed to monitor in situ the extent of the damage sustained by the murals.