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In the second of two papers, the atmospheric polybrominated diphenyl ethers (PBDE) deposition (wet and dry) at a municipal solid waste incineration (MSW) plant with electronics recycling is compared with that at an industrial urban reference site (URS) producing asphalt and concrete. Results of BDE209 and SigmaPBDE excluding BDE209 as representatives of "new" vs. "old" PBDEs are presented. Volume weighted mean SigmaPBDE and BDE209 concentrations at the MSW were 6.2 and 14.4 ng l(-1), and at the URS were 2.5 and 14.1 ng l(-1). Median SigmaPBDE and BDE209 deposition fluxes were 21.3, 63.8 and 7.0, 14.7 ng m(-2) day(-1) at the MSW and URS, respectively. The concentrations in precipitation and the deposition fluxes were significantly higher at the MSW compared to the URS. Measured total washout- ratios (W-T) were dependent on particle scavenging and the median WT for all congeners was 5.4x 10(5). Median dry particle deposition velocities ranged from 0.4 to 49 cm s(-1), depending on congener, showing that PBDEs are effectively removed from the atmosphere by particle deposition. PBDE fluxes increased at the reference site when winds were blowing from west south-west, i.e. from the direction of the MSW. PBDE deposition and washout ratios were not influenced by temperature or rain volume, suggesting a constant emission from the MSW regardless of weather conditions. Together with the results of paper I (Agrell et al., 2004, Atmospheric Environment, this issue) we therefore suggest that treatment of waste, e.g. electronics recycling, is more a source of "old" PBDEs to the environment, whereas the rather similar BDE209 concentrations at the two urban sites are more a result of proximity to potential diffuse sources. (C) 2004 Elsevier Ltd. All rights reserved. (Less) |
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