Abstract
In order to ascertain an indoor air quality and its effect on library and archival collections four intensive measuring campaigns were performed in the State Regional Archives in Třeboň and Department of Historical Archives of the Research Library of South Bohemia at Zlatá Koruna, Czech Republic over the period December 2011 – December 2012. The measurements included Indoor/Outdoor (I/O) dust particle number concentrations and size distributions, gaseous pollutants (SO2, NO2, O3, NH3, HNO3, and acetic and formic acids), temperature, relative humidity, microbiological contamination, and air exchange rate between indoor and outdoor environment.
In addition, size resolved chemical composition of indoor Particulate Matter (PM) was determined using Ion Chromatography (water soluble ions), PIXE (elements), and Thermo-Optical Transmission method (organic and elemental carbon). The results showed that the main contribution to indoor PM were dust particles, penetrating from the outdoor environment, that contained predominantly ammonium sulphate and nitrate, soot and organic matter.
A typical example of fine dust particles collected indoors is shown in Fig. 1. Spherical shape indicates traffic and local heating as probable source.
The results also showed that due to higher temperatures indoors ammonium nitrate can evaporate producing gaseous ammonia and nitric acid, followed by fast deposition of nitric acid on indoor surfaces. This process produced higher concentrations of ammonia indoors, compared to outdoor concentrations.
To find out possible negative effect of dust on paper degradation we deposited fine dust particles on cellulose filters.