Investigation of natural and anthropogenic hydrocarbon inputs in sediments using geochemical markers. II. São Sebastião, SP––Brazil

The São Sebastião Channel, NE São Paulo State, Brazil, is an area of environmental interest of that state not only because of the tourism, but also because of the presence of the most important oil terminal of Brazil, the PETROBRÁS Maritime Terminal (DTCS). Sediment samples were collected at 15 sites in the channel, extracted and analyzed by GC/FID and GC/MS for composition and levels of the following organic geochemical markers: aliphatic hydrocarbons (normal and isoprenoid alkanes), petroleum biomarkers, linear alkylbenzenes (LABs) and polycyclic aromatic hydrocarbons (PAHs). The total concentrations varied from 0.04 to 8.53 μg g−1 for aliphatics, from 51.1 to 422.0 ng g−1 for petroleum biomarkers, from 12.6 to 27.7 ng g−1 for LABs and from 20.4 to 200.3 ng g−1 for PAHs. The PETROBRÁS Maritime Terminal (DTCS), São Sebastião Harbor and sewage outfalls along the area had clear influences on the geochemical marker concentrations, especially at locales in the central and north parts of the channel.