title: Coexisting sea-based and land-based sources of contamination by PAHs in the continental shelf sediments of Coatzacoalcos River discharge area (Gulf of Mexico).
abstract: The oldest refinery and the major petrochemical complexes of Mexico are located in the lower reach of the Coatzacoalcos River, considered the most polluted coastal area of Mexico. A (210)Pb-dated sediment core, from the continental shelf of the Coatzacoalcos River, was studied to assess the contamination impact by the oil industry in the southern Gulf of Mexico. The sedimentary record showed the prevalence of petrogenic PAHs between 1950s and 1970s, a period during which waste discharges from the oil industry were not regulated. Later on, sediments exhibited higher contents of pyrogenic PAHs, attributed to the incineration of petrochemical industry wastes and recurrent wildfires in open dumpsites at the nearby swamps. The total concentration of the 16 EPA-priority PAHs indicated low levels of contamination (<100 ng g(-1)), except a peak value (>1000 ng g(-1)) during the late 1970s, most likely due to the major oil spill produced by the blowout of the Ixtoc-I offshore oil rig in deep waters of the southwestern Gulf of Mexico. Most of the PAH congeners did not show defined temporal trends but, according to a Factor Analysis, apparently have a common origin, probably waste released from the nearby oil industry. The only exceptions were the pyrogenic benzo(b)fluoranthene and benzo(a)pyrene, and the biogenic perylene, that showed increasing concentration trends with time, which we attributed to erosional input of contaminated soil from the catchment area. Our study confirmed chronic oil contamination in the Coatzacoalcos River coastal area from land based sources for more than 60 years (since 1950s).
authors.affiliation: Universidad Nacional Autónoma de México, Instituto de Ciencias del Mar y Limnología, Calz. J. Montes Camarena s/n, Col. Playa Sur, Mazatlan, Mexico. Electronic address: caro@ola.icmyl.unam.mx.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Ruiz-Fernández
authors.affiliation: Instituto de Investigaciones Marinas y Costeras, Calle 25 No. 2-55, Playa Salguero, Sta Marta, Colombia. Electronic address: julian.betancourt@invemar.org.co.
authors.forename: Julián Mauricio Betancourt
authors.initials: JM
authors.lastname: Portela
authors.affiliation: Geochemical and Environmental Research Group, Texas A&M University, 833 Graham Road, College Station, TX 77845, United States. Electronic address: jlsericano@geos.tamu.edu.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Sericano
authors.affiliation: Universidad Nacional Autónoma de México, Departamento de Procesos Oceánicos y Costeros, Instituto de Ciencias del Mar y Limnología, Circuito Exterior S/N, Ciudad Universitaria, 04510, México D.F., Mexico. Electronic address: jasanchez@cmarl.unam.mx.
authors.forename: Joan-Albert
authors.initials: JA
authors.lastname: Sanchez-Cabeza
authors.affiliation: Instituto de Investigaciones Marinas y Costeras, Calle 25 No. 2-55, Playa Salguero, Sta Marta, Colombia. Electronic address: luisa.espinosa@invemar.org.co.
authors.forename: Luisa Fernanda
authors.initials: LF
authors.lastname: Espinosa
authors.affiliation: Universidad Nacional Autónoma de México, Departamento de Procesos Oceánicos y Costeros, Instituto de Ciencias del Mar y Limnología, Circuito Exterior S/N, Ciudad Universitaria, 04510, México D.F., Mexico. Electronic address: gcardoso@ola.icmyl.unam.mx.
authors.forename: José Gilberto
authors.initials: JG
authors.lastname: Cardoso-Mohedano
authors.affiliation: Universidad Nacional Autónoma de México, Instituto de Ciencias del Mar y Limnología, Calz. J. Montes Camarena s/n, Col. Playa Sur, Mazatlan, Mexico. Electronic address: libia@ola.icmyl.unam.mx.
authors.forename: Libia Hascibe
authors.initials: LH
authors.lastname: Pérez-Bernal
authors.affiliation: Instituto de Investigaciones Marinas y Costeras, Calle 25 No. 2-55, Playa Salguero, Sta Marta, Colombia. Electronic address: jesus.garay@invemar.org.co.
authors.forename: Jesús Antonio Garay
authors.initials: JA
authors.lastname: Tinoco
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D060851:Gulf of America; D008800:Mexico; D061329:Oil and Gas Fields; D059392:Petroleum Pollution / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical
keywords: Coatzacoalcos River; Gulf of Mexico; Ixtoc-I blowout; Oil industry; PAHs; Sedimentary record