title: Characterization of HCHs and DDTs in urban dustfall and prediction of soil burden in a metropolis-Beijing, China.
abstract: The concentrations, spatial distribution and compositional patterns of extensively used hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in urban dustfall in a metropolis-Beijing are presented in this paper. The potential sources are discussed and soil burdens are predicted based on the fluxes. The hotspots in commercial areas are identified by spatial distribution maps and the fractional value isomers indicates that dustfall in urban Beijing are affected by both current and historical usage of DDTs. It is worth noticing that there is possible application "dicofol-type of DDTs" in Beijing. The measured atmospheric deposition flux is 1.14×10(5) ng h(-1) m(-2) for HCHs and 1.47×10(5) ng h(-1) m(-2) for DDTs, respectively. However, when compared with atmospheric deposition flux, the volatilization flux estimated from concentrations in soils by fugacity model is significantly lower for HCHs (2.41 ng h(-1) m(-2)) and DDTs (0.07 ng h(-1) m(-2)). The net atmospheric flux to the soil suggests that the levels of HCHs and DDTs in soil are dominated by atmospheric deposition and the urban soil in Beijing would be a sink for HCHs and DDTs in the long term.
authors.affiliation: Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China. hangxin@vip.sina.com
authors.forename: Hangxin
authors.initials: H
authors.lastname: Cheng
authors.forename: Lingling
authors.initials: L
authors.lastname: Ma
authors.forename: Chuandong
authors.initials: C
authors.lastname: Zhao
authors.forename: Xinghong
authors.initials: X
authors.lastname: Li
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wang
authors.forename: Yinghan
authors.initials: Y
authors.lastname: Liu
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
mesh_terms: D002681:China; D003634:DDT / Q000032:analysis*; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring; D001556:Hexachlorocyclohexane / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D025341:Principal Component Analysis; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D004391:Dust; D010575:Pesticides; D012989:Soil Pollutants; D001556:Hexachlorocyclohexane; D003634:DDT