title: 210Pb geochronology and trace metal fluxes (Cd, Cu and Pb) in the Gulf of Tehuantepec, South Pacific of Mexico.
abstract: Distributions of Al, Cd, Cu, Fe, Li, Mn and Pb were analyzed in a sediment core collected in the Gulf of Tehuantepec, an important fisheries region located in the South Pacific of Mexico, where data on metal accumulation and accretion rates were previously almost nonexistent. Depth profiles of metal concentrations were converted to time-based profiles by using a 210Pb-derived vertical accretion rate, estimated to be 0.05 cm year(-1) on the average. Sediments were dated up to 8 cm depth, corresponding to a layer of ca. 140 years old. The historical changes of metal accumulation along the sediment core have shown a moderate enrichment of Cd, Cu and Pb concentrations at present, of about threefold the corresponding background concentrations. Chronological trace metal records showed that metal fluxes have increased over the last 20 years, reaching the maximum values at present of 2.5, 22.5 and 45.8 (microg cm(-2) year(-1)) for Cd, Pb and Cu, respectively. These increments in metal fluxes are likely influenced by the development of anthropogenic land-based activities since over this period of time oil production activities in the region have had a significant development.
authors.affiliation: Mazatlán Academic Unit, Institute of Marine Sciences and Limnology--UNAM, Calz. Joel Montes Camarena s/n, 82040 Mazatlán, Sin., Mexico. caro@ola.icmyl.unam.mx
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Ruiz-Fernández
authors.forename: Federico
authors.initials: F
authors.lastname: Páez-Osuna
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Machain-Castillo
authors.forename: Elsa
authors.initials: E
authors.lastname: Arellano-Torres
mesh_terms: D004784:Environmental Monitoring; D055593:Geological Phenomena; D005844:Geology; D007856:Lead Radioisotopes / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis*; D008800:Mexico; D010140:Pacific Ocean; D010578:Petroleum; D014131:Trace Elements / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D007856:Lead Radioisotopes; D019216:Metals, Heavy; D010578:Petroleum; D014131:Trace Elements; D014873:Water Pollutants