Abstract

Study of the dispersion of persistent organic pollutants (POPs) throughout the environment is necessitated by their toxicological properties and propensity to accumulate in biota. In this study, we use data from the analysis of three (210)Pb dated soil profiles collected along a 30-m hydrological gradient to demonstrate postdepositional mobility of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). We found that (i) humus originating from litter exposed to surface fallout during the 1960-1970s contains the highest concentrations of PCDD/Fs and PCBs in the O-horizon of the soils; (ii) accumulation rates of PCDD/Fs and PCBs in the O-horizon (similar to 5.0 and similar to 210 mu g m(-2) yr(-1)) constituted only 9.1% and 3.5%, respectively, of the measured annual input, demonstrating that a minor fraction of the deposited material is retained within the O-horizon; (iii) POP inventories in the upper 0.5-0.9 m of the mineral soil constituted a considerable part (40-70%) of the total pool stored in the soil, implying significant vertical translocation of atmospheric derived POPs; and (iv) increasing downslope inventories of POPs suggest a lateral downward transport of POPs from uphill soils. The findings challenge the commonly accepted view that POPs fallout is effectively retained within O-horizons.

Published in

Environmental Science and Technology
2011, Volume: 45, number: 24, pages: 10378-10384

SLU Authors

• Wiberg, Karin

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • Umeå University

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1021/es200938z

Permanent link to this page (URI)

https://res.slu.se/id/publ/37364