Composição, origem e distribuição de hidrocarbonetos em sedimentos marinhos nas principais regiões portuárias da costa sudeste brasileira

Abstract

Regions where there are port activities are more susceptible to contamination by hydrocarbons due to transit of vessels and loading/unloading operations and, consequently, are more vulnerable to environmental impacts. This study evaluated the composition, distribution, and origin of hydrocarbons in eight ports in Southeastern Brazilian coast: Santos-SP, São Sebastião-SP, Angra dos Reis-RJ, Itaguaí-RJ, Rio de Janeiro-RJ, Arraial do Cabo-RJ, Macaé-RJ and Vitória-ES. Samples were collected from shallow marine sediments (0-2) in two years (2009 and 2010). Gas chromatography with flame ionization detector and gas chromatography coupled to mass espectrometria were respectively used to analyze the aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (HPAs) Average concentration and standard deviations of n-alkanes (μg g-1), Total Aliphatic (μg g-1), 16 priority HPAs (ng g-1) and Total HPAs (ng g-1) were 6.55 ± 4.52, 123.16 ± 86.12, 1470.24 ± 958.41 and 653.93 ± 482.81 in the region of Santos; 2.69 ± 1.16, 35.29 ± 15.22, 756.25 ± 350.28 and 142.35 ± 142.35 in the region São Sebastião; 3,11 ± 2,34, 56,99 ± 78,39, 777,62 ± 821,32 and 82,33 ± 84,62 in the region of Angra dos Reis; 5,58 ± 3,28, 26,55 ± 12,19, 1221,15 ± 1070,87 and 92,28 ± 93,14 in the region of Itaguaí; 5,09 ± 2,03, 179,22 ± 108,16, 3547,27 ± 3081,18 and 1879,05 ± 1792,69 in the region of Rio de Janeiro; 1.63 ± 2.15, 51.54 ± 39.50, 366.26 ± 222.89 and 194.83 ± 141.65 in the region of Arraial do Cabo; 3.92 ± 2.69, 50.42 ± 81.30, 643.97 ± 637.61 and 182.46 ± 265.87 in the region of Macae; and 4,78 ± 4,05, 45,31 ± 32,84, 868,78 ± 874,56 and 258,84 ± 142,89 in the region of Vitória, respectively. Contamination by oil in those studied regions was variable and could not be straightly related to the size and urban development around each port. In order to evaluate sources of contamination it were used selected diagnostic reasons. Contamination in most of areas revealed to be simultaneously influenced by a mix of sources (pyrolytic and petrogenic), probably related to port activities, urban and industrial wastes, and atmospheric routes.