title: Vertical fluxes and accumulation of trace metals in superficial sediments of the Río de la Plata estuary, Argentina.
abstract: Superficial sediments and settling material collected in Buenos Aires coastal area were analyzed to evaluate the accumulation and sources of trace metals. Residual elements showed homogeneous sedimentary concentrations (Fe: 23,846 +/- 4,367; Ni: 10 +/- 2.7; Mn: 706 +/- 314 μg g(-1)) whereas anthropogenic metals presented exponentially decreasing offshore gradients (Zn: 98 +/- 69; Cr: 28 +/- 21; Cu: 19 +/- 15; Pb: 18 +/- 13 μg g(-1)). Anthropogenic impact was evaluated through metal-Fe relationships, Fe-normalized enrichment factors and sediment quality guidelines. The slopes of metal-Fe regressions from background sites were comparable to upper crust metal ratios, excepted Cr which is impoverished, and Mn which is diagenetically enriched. Metal-Fe relationships also hold for most 2.5 km offshore sites but with higher slopes denoting human influence, and are completely lost in 1-2.5 km sediments and trap material which plot over the regressions and exceed sediment quality guidelines.
authors.affiliation: Laboratorio de Química Ambiental y Biogeoquímica, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Av. Calchaqui km 23500, Florencio Varela, Buenos Aires, 1888, Argentina.
authors.forename: L M
authors.initials: LM
authors.lastname: Tatone
authors.forename: C
authors.initials: C
authors.lastname: Bilos
authors.forename: C N
authors.initials: CN
authors.lastname: Skorupka
authors.forename: J C
authors.initials: JC
authors.lastname: Colombo
mesh_terms: D001118:Argentina; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D008670:Metals / Q000032:analysis*; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical