Effects of Saline Solutions on Paper-Based Cultural Heritage: Non-Invasive Techniques for Studying Flooded Ancient Books

Archival materials are increasingly vulnerable to damage from chemical, physical, biological, and environmental factors, including climate change-related extreme weather events such as torrential rains and flash floods. These conditions pose significant risks to paper-based cultural heritage, leading to degradation from both water and salt exposure. This study investigates the effects of direct immersion in saline solutions on different types of paper, simulating the impact of flooding events. We focused on how varying levels of salinity affect the crystalline structure of paper, which is crucial for understanding its degradation. This study employed non-invasive, portable optical techniques such as luminescence, reflectivity, and Raman spectroscopy to monitor the changes in the paper structure. Our results showed that salt exposure leads to significant alterations in the paper’s crystalline composition. The study concludes that washing treatments are essential for mitigating further degradation, highlighting the importance of timely intervention in preserving cultural heritage. The non-destructive nature of the methods used also demonstrates their potential for in situ applications in cultural heritage conservation.