In order to determine sources of particulate matter (PM) inside the National Library in Prague, transport between indoor and outdoor environment, transport inside the Library and deposition on books and manuscripts, we measured size resolved particle number concentrations of PM using Scanning Mobility Particle Sizer (3936L, TSI, USA) and Aerodynamic Particle Sizer (3321, TSI, USA), sampling alternately indoors and outdoors of Baroque Library Hall. In parallel spatial distribution of PM was measured by four DustTrak instruments (8520, TSI, USA), located at different positions and heights inside the Hall.
During the sampling air exchange rate was measured by Indoor Air Quality Monitor PS 32 (Sensotron, Poland) and size resolved PM was sampled with two Berner type Low Pressure Impactors (BLPI, 25/0.018/2, Hauke, Austria) for subsequent analysis. The deposition of particles on indoor surfaces was examined using Whatman filters located on the free shelf of the Library.
All measurements were performed during three intensive campaigns in 2009. Measurements of indoor PM, performed in the National Library in Prague showed the main source of coarse particles were visitors and main source of submicron particles was atmospheric PM, penetrating indoors from the outdoor environment.
The particles were uniformly distributed indoors and contained ammonium sulphate. Deposition experiments showed that submicron particles can penetrate into gaps between pages of books by Brownian diffusion.