Effects of Environmental Pollution on Sandstone Heritage Deterioration: An In-situ Investigation and Laboratory Leaching-aging Simulation

Environmental pollution affects both human health and the preservation of cultural heritage in urban contexts. Gaseous and particulate pollutants have caused severe degradation of stone heritage worldwide. In this study, integrated in-situ field investigations and laboratory leaching-aging simulations were conducted using complementary analytical techniques to investigate the effects of saline components in particulate pollutants on stone heritage. The field investigation revealed that the development of black crusts, powdering, and efflorescence on stone was closely associated with saline pollutants. Leaching-aging simulations further confirmed the critical role of these pollutants in surface degradation. Quantitative analysis showed that saline pollutants substantially altered the macroscopic properties of sandstone surfaces, including relief amplitude, water absorption capacity, surface free energy, and Leeb hardness. These findings contribute to a deeper understanding of the mechanisms by which saline pollutants drive the degradation of sandstone heritage, thereby providing insights for developing effective conservation practices.