Volume 11, No. 1, February 2011, Pages 70-79 PDF(399 KB)
Chemical Composition of Indoor and Outdoor Atmospheric Particles at Emperor Qin's Terra-cotta Museum, Xi’an, China
Jun-ji Cao1,5, Hua Li1,4, Judith C. Chow2, John G. Watson2, Shuncheng Lee3, Bo Rong4, Jun-gang Dong6, Kin-fai Ho1
1 SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, China
2 Division of Atmospheric Sciences, Desert Research Institute, Reno, USA
3 Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hong Kong, China
4 Emperor Qin's Terra-cotta Warriors and Horses Museum, Xi’an, China
5 Institute of Global Environmental Change, Xi’an Jiaotong University, Xi’an, China
6 Xi’an University of Architecture and Technology, Xi’an, China
Indoor particles and microclimate were measured in summer (August 2004) and winter (January 2005) periods inside and outside Emperor Qin's Terra-Cotta Museum in Xi’an, China. Indoor temperature ranged from 21.9°C to 32.4°C in summer and from 0°C to 5.3°C in winter. Relative humidity varied from 56% to 80% in summer and from 48% to 78% in winter. The number concentrations of particles were lower (0.3–1.0 μm) in summer, and were higher (1.0–7.0 μm) in winter. The average indoor PM2.5 and TSP concentrations were 108.4 ± 30.3 μg/m3 and 172.4 ± 46.5 μg/m3 in summer and were 242.3 ± 189.0 μg/m3 and 312.5 ± 112.8 μg/m3 in winter, respectively. Sulfate, organic matter, and geological material dominated indoor PM2.5, followed by ammonium, nitrate, and elemental carbon. Several milligram of sulfate particles can deposited in the museum per square meter each year based on the dry deposition estimate. High concentrations of acidic particles suspended inside the museum and their depositions have high risk for the erosion of the terra-cotta figures.
Terra-cotta museum; Indoor air quality; Chemical composition; Acidic particles.