title: Polycyclic aromatic hydrocarbon storage in a typical Cerrado of the Brazilian savanna.
abstract: There may be important biological sources of polycyclic aromatic hydrocarbons (PAHs) to the global environment, particularly of naphthalene, phenanthrene, and perylene, that originate in the tropics. We (i) studied the distribution of PAHs among different compartments of a typical Cerrado to locate their sources and (ii) quantified the PAH storage of this ecosystem. The sum of 20 PAH (sigma20PAHs) concentrations ranged from 25 to 666 microg kg(-1) in plant tissue, 7.4 to 32 microg kg(-1) in litterfall, 206 to 287 microg kg(-1) in organic soil, and 10 to 79 microg kg(-1) in mineral soil. Among the living biomass compartments, the bark had the highest mean PAH concentrations and coarse roots the lowest, indicating that PAHs in the plants originated mainly from aboveground sources. Naphthalene and phenanthrene were the most abundant individual PAHs, together contributing 33 to 96% to the sigma20PAHs concentrations. The total storage of the X20PAHs in Cerrado was 7.5 mg m(-2) to a 0.15-m soil depth and 49 mg m(-2) to a 2-m soil depth. If extrapolated to the entire Brazilian Cerrado region, roughly estimated storages of naphthalene and phenanthrene correspond to 7300 and 400 yr of the published annual emissions in the United Kingdom, respectively. The storage of benzo[a]pyrene, a typical marker for fossil fuel combustion, in the Cerrado only corresponds to 0.19 yr of UK emissions. These results indicate that the Brazilian savanna comprises a huge reservoir of naphthalene and phenanthrene originating most likely from the aboveground parts of the vegetation or associated organisms. Thus, the Cerrado might be a globally important source of these PAHs.
authors.affiliation: Department of Soil Science, Institute of Ecology, Berlin University of Technology, Salzufer 11-12, D-10587 Berlin, Germany. wolfgang.wilcke@tu-berlin.de
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wilcke
authors.forename: Martin
authors.initials: M
authors.lastname: Krauss
authors.forename: Juliane
authors.initials: J
authors.lastname: Lilienfein
authors.forename: Wulf
authors.initials: W
authors.lastname: Amelung
mesh_terms: D018533:Biomass; D001938:Brazil; D017753:Ecosystem; D004784:Environmental Monitoring; D018517:Plant Roots / Q000737:chemistry; D006109:Poaceae; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012987:Soil
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil