Health Risk Assessment in the Mass Recovery of Flood-Damaged Archival and Library Collections

Flood events have increased significantly in recent decades as a result of climate change, causing severe damage to cultural heritage and, in particular, to archival and library collections. Paper-based materials contaminated by floodwaters and alluvial mud are subject not only to physical and biological deterioration but also to potential hygienic and sanitary hazards associated with the persistence of human pathogens. Current emergency recovery strategies mainly focus on stabilizing materials through freezing, freeze-drying and mechanical cleaning, while health risk assessment is rarely addressed systematically. This pilot study proposes an innovative operational protocol that integrates microbiological indicators of hygienic relevance into the conservation workflow for assessing health risks during the remediation of flood-damaged archival and library materials. Its innovative character lies in shifting post-flood recovery from a predominantly material-stabilization approach toward a combined conservation and occupational-health framework, in which faecal contamination indicators, total microbial loads and selected viral targets are monitored before and after key remediation steps. The protocol was applied to collections from the Aurelio Saffi Municipal Library of Forlì (Italy), severely affected by the Emilia-Romagna floods of May 2023. The results indicate a substantial reduction in faecal contamination following freeze-drying, alongside the persistence of environmentally resistant microbial taxa. However, these findings should be regarded as preliminary and case-specific, and the proposed protocol will require validation through additional case studies, larger sample sets and controlled experimental trials before it can be considered broadly applicable. These findings highlight the need to integrate health risk considerations into conservation recovery workflows to support the safety of conservation professionals and users of recovered heritage materials.