On January 18, 2000, approximately 340,000 gallons (1,300 m3) of marine fuel (MF-380) spilled into Guanabara Bay, Rio de Janeiro, Brazil. The spill originated from a leak in the pipeline from the PETROBRAS refinery to the oil terminal. This paper presents the results for the water column and sediment monitoring 10 days after the spill, including n-alkanes, unresolved complex mixture (UCM), polycyclic aromatic hydrocarbons (PAHs), and toxicological essays. Chemical and toxicological monitoring of the water column was performed at 14 sampling stations throughout the impacted area in Guanabara Bay. The chemical analysis of PAHs by ultraviolet fluorescence showed results from <0.04–11.56 μg/L−1in chrysene equivalents. The toxicological essays for three species (Artemia sp., Mysidium gracile, and Vibrio fisheri, Microtox) indicate no acute effects for the water samples studied. To monitor sediments, 57 samples were collected from intertidal and sub tidal sites. For the 30 intertidal sediments, 73% contained PAHs (GC-MS) below 2 μg/g−1, 20% were in the range 2–5 μg/g−1, and only two stations (7%), located in the vicinity of the spill point, contained levels up to 20 μg/g−1. For the 27 subtidal sediments, results were in the range of 0.2–9.6 μg/g−1 for PAHs, 0.7–43.3 μg/g−1 for n-alkanes, and 17.8–1,250 μg/g−1 for UCM. The toxicological study for the sediments based on Vibrio fisheri (Microtox) indicated no acute toxicity effects. When comparing the post-spill results with previous hydrocarbon data, no significant impact was observed in sediments and water column because of the oil spill. There is, however, a significant background of chronic anthropogenic inputs to Guanabara Bay.

Faced with the latest experiences on Brazilian oil spill incidents, Petrobras has been trying to overcome many challenges in environmental management and operational safety, aiming to prevent environmental risks. This paper presents the oil characterizations and monitoring studies in affected ecosystems such as the hot spots on soils affected by the Iguassu River oil spill (occurred in July 2000, due to a pipeline rupture in the scraper area of REPAR, a Petrobras refinery located in the state of Parana), by the Vessel Vergina II oil spill in São Sebastião channel (located in the state of São Paulo, occurred in November 2000) and lastly, the Guanabara Bay oil spill (a pipeline rupture that occurred in January 2000, due to a pipeline rupture between oil terminal and REDUC, a Petrobras refinery located in the state of Rio de Janeiro). Chemical analysis were performed in different sample matrixes including many parameters such as total petroleum hydrocarbons (TPH), aliphatic compounds (n-alkanes), unresolved complex mixtures (UCM), benzene, toluene, ethylbenzene and xylenes (BTEX), polycyclic aromatic hydrocarbons (PAH), terpanes and steranes, that are the parameters usually monitored after a spill oil. Visual inspections were also performed mainly in Guanabara Bay in order to identify the affected ecosystems by the spilled oil and to plot maps of classified regions based on the level of visual oil contamination. The acute toxicity was evaluated in water soluble fraction (WSF) of the spilled oils using ecotoxicological tests.