A multi-molecular marker assessment of organic pollution in shore sediments from the Río de la Plata Estuary, SW Atlantic

Abstract

Organic pollution was evaluated in surface sediments along the middle portion of the Río de la Plata Estuary, SW Atlantic. A multi-molecular marker approach was performed to identify major sources of organic compounds using diagnostic indices. The relative contribution of different sources of hydrocarbons was quantified by source apportionment employing Principal Component Analysis/Multiple Linear Regression (PCA/MLR) as chemometric technique. All molecular markers indicated high chronic organic pollution in the stations of Montevideo Bay. Main sources of aliphatic and polycyclic aromatic hydrocarbons were petroleum inputs and combustion, due to oil transport and refinement, harbour activities and vehicular emissions. Major sources of linear alkylbenzenes and steroids were industrial and domestic sewage. Although, significant anthropogenic inputs, a natural footprint of terrestrial higher plants contribution was recognized. Multi-molecular marker and comprehensive assessments can improve the establishment of more precise regulation actions to reduce pollution levels.

Keywords: Chemometric technique; Estuarine sediments; Multi-molecular indicators; Source diagnostics; Uruguay.