Degradation potential of airborne particulate matter at the Alhambra monument: a Raman spectroscopic and electron probe X‐ray microanalysis study

Airborne particulate matter (APM) at the Alhambra monument, a UNESCO World Heritage Site and masterpiece of Islamic art, poses significant degradation risks to its cultural heritage. A study using Raman spectroscopy and electron probe microanalysis revealed that up to 50% of finer APM fractions consist of hygroscopic salts like sodium and ammonium nitrates/sulfates, while soot—reaching 55% in some cases—contributes to both chemical attack and soiling. Brightly colored particles suggest ongoing pigment degradation. The research applied molecular and elemental techniques sequentially, providing a detailed degradation potential profile for outdoor heritage environments.

Potgieter‐Vermaak, S., Horemans, B., Anaf, W., Cardell, C., & Grieken, R. V. (2012). Degradation potential of airborne particulate matter at the Alhambra monument: a Raman spectroscopic and electron probe X‐ray microanalysis study. Journal of Raman Spectroscopy, 43(11), 1570–1577. Portico. https://doi.org/10.1002/jrs.4052