Characterization of indoor air quality in different archives - Possible implications for books and manuscripts

Concentrations of NO2, SO2, O3, acetic and formic acids, HNO3, and NH3 were measured indoors and outdoors at five different archives (three naturally ventilated and two filtrated). Intensive sampling was performed over a one-year period at every location using diffusive samplers in order to reveal sources of pollutants, to determine the relationship between indoor and outdoor environments, and to evaluate the potential influence of the indoor air quality on archival collections. The results revealed that NO2, SO2, and O3 penetrate indoors from the outdoor air. Acetic and formic acids were produced indoors by the decomposition of paper-based books. Sources of ammonia and nitric acid were the infiltration, evaporation of ammonium nitrate that penetrated indoors from the outdoor air, and emissions of ammonia from building materials. The results showed that among all the observed archives, only the depository equipped with filters for gaseous pollutants, is suitable for the long-term storage of books and manuscripts.