Keywords: heavy metals, PAHs, polycyclic aromatic hydrocarbons, marine sediments, continental shelf, Gulf of Mexico, organic pollutants, inorganic pollutants, water pollution, costal waters, oil spills
Organic and inorganic pollutants in marine sediments from northern and southern continental shelf of the Gulf of Mexico
The present work was developed in the continental shelf of Tamaulipas, Veracruz and Tabasco during 1999–2000 in the Gulf of Mexico. The main goal of this study was to evaluate levels of heavy metals (Cr, Ni, Pb and Cd) in total and bioavailable concentration, as well as the polycyclic aromatic hydrocarbons (PAHs); the organic matter and carbonates were determinated too. Heavy metals in total concentration showed the following behaviour: Cr > Ni > Pb > Cd; the bioavailable fraction showed the following pattern: Pb > Ni > Cr > Cd. The best statistical relation was Ni-Cr showing similar sorption mechanisms between them. In Tamaulipas was obtained the maximum level of PAHs with 29.6 µgg-1 followed by Veracruz (12.4µgg-1). The more abundant PAHs were: Chrysene, Benzo(a)anthracene, Benzo(k)fluoranthene, Benzo(a)pyrene, Benzo(b)fluoranthene and Pyrene, this fact basically means a pyrolitic origin, and all of these compounds are due to human and industrial activities; however, It is worth to mention that the presence of light PAHs such as naphthalene, means that they proceed from recent oil spills.