title: Background values for evaluation of heavy metal contamination in sediments in the Parnaíba River Delta estuary, NE/Brazil.
abstract: This study establishes regional background levels and upper thresholds (geochemical baseline) for Zn, Cu, Pb, Cr, Mn, and Fe from surface samples and profiles taken in 16 sedimentary environments of the Parnaíba River Delta estuary, NE-Brazil. Three approaches were applied to evaluate metal contamination: normalization to Fe, statistical analysis and sediment quality guidelines or environmental assessment criteria (TEL-PEL). Metal concentrations in sediments ranged from 2.4 to 31 mg Zn kg(-1), 1.5 to 48 mg Cu kg(-1), 1.3 to 28 mg Pb kg(-1), 1.5 to 38 mg Cr kg(-1); 145 to 1,356 mg Mn kg(-1), and 0.3% to 2.5% for Fe. All metals showed positive correlations with the <0.63 μm sediment fraction, indicating a significant association with rich lithogenic sources of iron oxide-hydroxides. Results suggest a low probability of adverse effects to the local aquatic biota. The background values of the area were lower than those reported for other areas of the northeastern coast of Brazil.
authors.affiliation: Universidade Federal do Piauí, Campus Prof(a) Cinobelina Elvas, Rod. BR 135, Km 03, s/n, Planalto Horizonte, 64.900-000 Bom Jesus, PI, Brazil. Electronic address: franciscojose@ufpi.edu.br.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: de Paula Filho
authors.affiliation: Universidade Federal do Ceará, Instituto de Ciências do Mar/LABOMAR, Av. da Abolição, 3207, 60.165-081 Fortaleza, CE, Brazil.
authors.forename: Rozane Valente
authors.initials: RV
authors.lastname: Marins
authors.affiliation: Universidade Federal do Ceará, Instituto de Ciências do Mar/LABOMAR, Av. da Abolição, 3207, 60.165-081 Fortaleza, CE, Brazil.
authors.forename: Luiz Drude
authors.initials: LD
authors.lastname: de Lacerda
authors.affiliation: Universidade Federal do Ceará, Instituto de Ciências do Mar/LABOMAR, Av. da Abolição, 3207, 60.165-081 Fortaleza, CE, Brazil.
authors.forename: José Edvar
authors.initials: JE
authors.lastname: Aguiar
authors.affiliation: Universidade Federal do Ceará, Instituto de Ciências do Mar/LABOMAR, Av. da Abolição, 3207, 60.165-081 Fortaleza, CE, Brazil.
authors.forename: Tiago Farias
authors.initials: TF
authors.lastname: Peres
mesh_terms: D001938:Brazil; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis*; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy
keywords: Background levels; Diffuse sources; Heavy metals; Parnaíba River Delta