Investigation of natural and anthropogenic hydrocarbon inputs in sediments using geochemical markers. I. Santos, SP--Brazil.

A study on the inputs of organic matter to marine sediments of Santos Bay and Estuary, located in southeastern São Paulo State, Brazil, is presented here. The following geochemical markers were identified and quantified: aliphatic hydrocarbons (normal and isoprenoid alkanes), petroleum biomarkers, linear alkylbenzenes (LABs) and polycyclic aromatic hydrocarbons (PAHs). Sediment samples, collected at 15 sites in the bay and surrounding channels, were extracted and analyzed by gas chromatography with flame ionization and mass spectrometer detectors. Total concentrations varied from 0.17 to 107.80 microg g(-1) for aliphatics, from 47.2 to 2560.1 ng g(-1) for petroleum biomarkers, from 16.9 to 430.6 ng g(-1) for LABs and from 79.6 to 15389.1 ng g(-1) for PAHs. Anthropogenic contributions were apparent, indicating the influences of the Cubatao industrial complex, sewage outfalls along the area, the waste deposit of Santos city and storage facilities for petroleum and derivatives, based on the higher concentrations of geochemical markers detected.