Mauricio Mussi Molisani

Emissões naturais e antrópicas de nitrogênio, fósforo e metais para a bacia do Rio Macaé (Macaé, RJ, Brasil) sob influência das atividades de exploração de petroleo e gás na Bacia de Campos

Emission factors of natural processes and anthropogenic activities were used to estimate nutrients and metal loads for the lower Macae river basin, which hosts the operational base for the offshore oil and gas exploration in the Campos Basin. The estimates indicated that emissions from anthropogenic activities are higher than natural emissions. Major contributing drivers include husbandry and urbanization, whose effluents receive no treatment. The increasing offshore oil exploration along the Brazilian littoral has resulted in rapid urbanization and, therefore might increase the inshore emission of anthropogenic chemicals in cases where effective residue control measures are not implemented in fluvial basins of the region.

Hydrocarbons and trace metals in mussels in the Macaé coast: Preliminary assessment for a coastal zone under influence of offshore oil field exploration in southeastern Brazil.

Concentrations of PAHs and metals were obtained from mussels collected in beaches, coastal island and estuary of the Macaé coast, the main operational basin for offshore oil exploration in Brazil. This survey provides reference levels for scenarios of increasing exploration, as well as for other areas of the coast undergoing urbanization to support exploration. As expected, urban areas such as the Macaé river estuary presented high concentrations of PAHs, although unsuspected sites such the island also presented signs of contamination. PAH in mussels originated from pyrolytic and petrogenic sources. Metals were typical of non-contaminated coastal environments, although Cr concentrations were above Brazilian Reference Levels.

Mismatch Between Sediment Metal Distribution and Pollution Source Gradient: A Case Study of a Small-Size Drainage Basin (Southeastern Brazil)

Metal contamination in aquatic environments may occur when the anthropogenic emission exceeds the natural contribution although other factors might influence the metal distribution. In the small-size Macaé river basin, most of the metal emission was originated from anthropogenic sources suggesting a contamination status. Total and exchangeable metal concentrations were determined in sediments from the pristine upstream to the urban estuary and compared to the metal content in rocks to establish contamination and background concentrations. The enrichment of Pb in sediments compared to the regional background and high exchangeable concentrations suggest the influence of anthropogenic sources on Pb distribution. Al, Fe Mn, Zn, Ba, Cu, Cr, Ni concentrations in sediments were similar to the rock content and the values were considered regional background. Spatial distribution did not follow the whole-basin emission source gradient suggesting that despite actual anthropogenic sources, the sediment mineralogy and basin geomorphology might influence the sediment metal distribution.