Fig. 4From: Monitoring the accumulated water soluble airborne compounds deposited on surfaces of showcases and walls in museums, archives and historical buildingsFrom the vault of the 2008 archival building holding the Arnamagnaean Collection of rare books. Two sampling sites were selected; the first site was on the white painted wall next to the steel door, the second site was on the dark grey vault door itself (Photo: Morten Ryhl-Svendsen)Back to article page