Occurrence and transport of PAHs, pesticides and alkylphenols in sediment samples along the Ebro River Basin

An environmental monitoring program was carried out to determine the occurrence of 69 pollutants in sediments collected along the Ebro River Basin. PAHs, polar and chlorinated pesticides and alkylphenols were monitored during the period 2004–2006 in 22 sampling sites. Target compounds were determined by pressurized liquid extraction followed by gas chromatography–mass spectrometry. Environmental data were assessed using descriptive statistical analysis and multivariate data analysis with Principal Component Analysis (PCA) to elucidate the relevant contamination patterns and provide a description of their seasonal trends. Comparison with legislated and toxicological values permitted to evaluate the environmental impact. PAHs and APs appeared in over 55% of the samples analyzed at concentrations up to 4931 and 5999 μg kg−1, respectively, and DDTs were detected over the toxicological values in more than 20% of the samples analyzed, although they are forbidden in Spain since 1994. PCA analysis showed two main contamination sources, one due to PAHs and a second one due to chlorinated compounds (DDTs and hexachlorobenzene). Hot spot areas were identified close to the more industrialized areas.