Background level and chemical composition of the atmospheric particulate matter in Mogao Grottoes
The atmospheric particulate matter is a kind atmospheric pollutant that threatens heritage sites and cultural relics.The deposition or adsorption of the particulate matter can cover the surface details of cultural relics,reducing the aesthetic value and causing further physical or chemical damages.With the goal of obtaining the chemical composition of the atmospheric particulate matter in a cultural heritage preservation environment,the mass concentration and chemical composition of TSP,PM10 and PM2.5 in open caves(Cave 16 and Cave 257),a non-open cave(Cave 320)and outside were analyzed.In each observation season,the mass concentration of TSP ranged from 48.4 µg/m3 to 60.0 µg/m3,that of PM10 ranged from 13.3 μg/m3 to 61.3 pg/m3,and that of PM2.5 ranged from 9.9 µg/m3 to 59.2 µg/m3.Whether or not the cave was open to the public had no significant effect on the concentration level and composition of the particulate matter in the cave,and the average I/O ratio of particulate mass concentration was mostly less than 1 in all caves,indicating that the particulate matter in caves mainly came from outdoor infiltration.Crust-derived mineral dust dominated the chemical composition of particles in all caves,accounting from 53.0％to 80.7％in spring and between 17.1％and 44.0％in winter.For other chemical components,the proportion of carbon and total water-soluble inorganic ions in fine particles was significantly higher than that in coarse ones.In winter,although the mass concentration of PM2.5 inside caves was relatively lower,the concentration and proportion of carbon and inorganic ions were higher than those in spring.The content percentage of carbon components and water-soluble inorganic ions was up to 60％.For the pollution control of the atmospheric particulate matter in Mogao Grottoes,attention should be paid to the hazards of fine particles and their chemical compositions.
Mogao GrottoesAtmospheric particulate matterMass concentrationChemical compositionHeritage conservation
万方数据
维普
