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Polycyclic Aromatic Hydrocarbon Storage in a Typical Cerrado of the Brazilian Savanna
Author(s) -
Wilcke Wolfgang,
Krauss Martin,
Lilienfein Juliane,
Amelung Wulf
Publication year - 2004
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2004.0946
Subject(s) - phenanthrene , environmental chemistry , pyrene , naphthalene , environmental science , polycyclic aromatic hydrocarbon , chemistry , litter , hydrocarbon , agronomy , biology , organic chemistry
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 (Σ20PAHs) concentrations ranged from 25 to 666 μg kg −1 in plant tissue, 7.4 to 32 μg kg −1 in litterfall, 206 to 287 μg kg −1 in organic soil, and 10 to 79 μg 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 Σ20PAHs concentrations. The total storage of the Σ20PAHs 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.