Nitrogen compounds in buildings housing collections: a preliminary review

Indoor climate and air pollutants are environmental stressors that can directly/indirectly affect the natural progressive ageing of materials constituting cultural heritage and be also responsible for accelerating or triggering degradation mechanisms. This preliminary literature review is based on a three‐step procedure through the PRISMA (Preferred Reporting Items for Systematic reviews and Meta‐Analyses) flow diagram, leading to the inclusion of 42 articles from two databases (Scopus and Web of Science), over the period 1966-2020. The review concerns nitrogen compounds in confined conservation spaces. The topic is mainly published in journal concerning the “environmental sciences” and by a first author affiliated to an Italian institution. Moreover, 40% of the sites are equipped with HVAC (Heating, Ventilation and Air Conditioning) systems, coupled or not with filters. Finally, the NO2 concentration is heterogeneous among sites located in Europe, considering both the sampling site and the presence of HVAC systems, with a minimum concentration value of 0.2 μg/m3 and a maximum of 99.7 μg/m3.