Coupled anthropogenic anomalies of radionuclides and major elements in estuarine sediments.
Concentrations of fertilizer industry-derived P (up to 3.4%), Ca (up to 6.1%), (226)Ra (up to 744 Bq kg(-1)) and (210)Pb (up to 1317 Bq kg(-1)) at least one order of magnitude above natural levels were recorded in a sediment core from Morrão River estuary (SE Brazil). Unsupported (210)Pb (= total (210)Pb-(226)Ra) activities unexplained by atmospheric fallout and deviations from the radionuclides secular equilibrium also indicated strong anomalies. Anomalous constituents were positively correlated with each other and negatively correlated with clay mineral-bearing elements. These negative correlations were explained by a depletion of natural sediment constituents due to a dilution caused by elevated inputs of steel industry-derived elements (mainly by Fe levels up to 24%). Absolute data and normalizations by a proxy for clays (Al) and anthropogenic Fe evidenced variabilities in the quality of coastal and land-derived sediment inputs, mainly due to changes in the relative contributions from industrial sources.
Machado
W
W
Departamento de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil. wmachado@geoq.uff.br
Luiz-Silva
W
W
Sanders
C J
CJ
Patchineelam
S R
SR
D002118:Calcium / Q000032:analysis; D005308:Fertilizers; D019015:Geologic Sediments / Q000737:chemistry*; D007856:Lead Radioisotopes / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D011886:Radon / Q000032:analysis; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D005308:Fertilizers; D007856:Lead Radioisotopes; D014875:Water Pollutants, Radioactive; D010758:Phosphorus; D011886:Radon; D002118:Calcium