Notice of RetractionDepth Profiles of Particulate Matter and Elements in Particulate Matter in Xi'an, China

Abstract

Depth profiles of particulate matter and elements in particulate matter collected from two typical resident buildings of a 7-storey building (B1) and a 24-storey building (B2) in the city of Xi'an, China were investigated. Physical characterization and chemical analysis of the settled dusts collected at different heights of B1 and B2 in April 2009 showed that (1) the volume percent for the fine particles (particle size <;10.5 μm) of the settled dusts was 26%-31% from B1 and 27%-38% from B2. The depth profiles showed an inversion layer at ~21 m above ground: when lower than 21 m, the volume percent for the fine particles increased while that of the coarse particles (particle size >;10.5 μm) decreased with increasing height; when higher than 21 m, the distribution patterns reversed. The re-suspension by wind serious impact on the dusts collect by dry traps than collected by wet traps; (2) the concentrations for 8 out of 25 elements analyzed were 3-15 times higher relative to soil background values in China. The contents of two of the elements analyzed, Mo and S, in the sample collected at 12 m, were 3 and 18 times, respectively, the value at 66m in B2. The content distribution for the remaining elements appeared to be height independent. Work is in process on persistent organic pollutants in the settled dusts.