Air quality in archives housed in historic buildings: Assessment of concentration of indoor particles of outdoor origin

摘要

Indoor air pollution in archives can cause irreversible degradation of materials stored there. Thus, detailed information about indoor air quality is essential before control strategies could be investigated. In a period 2008-2019, the relationship between the indoor and outdoor pollution was investigated in four naturally ventilated archives located in historical buildings and situated in regions with different outdoor air quality. The indoor and outdoor particle number, mass, and chemical size distributions were measured during different seasons. Moreover, air change rates (a), penetration coefficients (P), and deposition velocities (V-d) were determined. The results revealed that the most important source of the indoor particulate matter was the outdoor air. The size-resolved data with no indoor sources were evaluated using the steady-state solution of the mass balance equation as the I/O ratio. The results showed that all parameters (a, P, and V-d) determined in archives were comparable with low seasonal variation, probably due to the similar building characteristics. Further, the typical average values of the I/O ratio for naturally ventilated historical buildings were estimated. Finally, the long-term indoor concentrations, for periods when no measurement was in place, were determined using data from the local monitoring network. The results showed that the higher level of pollution and therefore the higher degree of degradation is expected in depositories located in highly polluted regions.