Characterization of harbor sediments from the English Channel: assessment of heavy metal enrichment, biological effect and mobility

- EF show an anthropogenic inputs in sediments for As, Cd, Pb and Zn.
- AEI suggest adverse biological effect for at least one element in samples.
- The relationship between AEI and EF are very different from one element to another.
- Correlations prove a link between mobility and enrichment for Cd, Cr, Ni, Pb and Zn.

For a full assessment of the environmental risk posed by dredged sediments not only the anthropogenic enrichment of contaminants, but also their mobility and biological impact should be considered. This study reports on the enrichment factor (EF), mobility, and Adverse Effect Index (AEI) of metals and metalloids in nine dredged sediments. Significant enrichment of As, Cd, Pb and Zn with respect to background values is detected, and calculated AEI values for these elements suggest that it is possible that a corresponding biological effect may be observed. Correlation coefficients also reveal a link between mobility in HCl and enrichment for Cd, Cr, Ni, Pb and Zn, however As and Cu do not display such a link, possibly suggesting that the source of contamination for these elements is less recent. Mobility and enrichment are two parameters which are often studied separately; however this paper shows that in some cases strong correlations occur.