Aerosol Particles in the Indoor Environment of the National Library in Prague

Particulate matter in the indoor air in exhibition rooms is a serious risk to works of art stored there. In the Baroque Library Hall of the National Library we examined concentrations and compositions of aerosol particles during 4 intensive campaigns in different seasons of year. Time variation of fine particles concentration indicated outdoor origin with traffic as the most probable source. The concentration of coarse particles revealed periodic increase and decrease, corresponding to beginning and end of visiting hours, indicating visitors as a source of these particles. The major water-soluble inorganic components of the fine particle mode were ammonium sulphate and nitrate, with indoor nitrate concentrations decreasing to zero. It was apparently caused by evaporation of ammonium nitrate after penetration indoors. Crustal elements in both indoor and outdoor samples were predominantly associated with coarse particles