Environmental and ecological risk assessment of heavy metals in sediments of Nador lagoon, Morocco

Heavy metal assessment in Nador lagoon (Mediterranean coast) was carried out using different environmental indices. In addition, heavy metal concentrations were measured in sediment samples and compared with consensus-based sediment quality guidelines. The spatial distributions of the main contamination sources of heavy metals were identified and described using chemometric and geographic information system methods. The results show that heavy metals occur in lagoon sediments largely due to the anthropogenic activities in the area (urban effluents). The concentrations of heavy metals found in surface sediments are significantly higher than those from the local background. The potential ecological risk index and other environmental indices produced similar values for the levels of heavy metal pollution in Nador lagoon sediment, thereby confirming each other's results. Pollution indices and statistical analysis show that the heavy metals pose an ecological risk and indicate that Nador lagoon is moderately to considerably pollute. (C) 2014 Elsevier Ltd. All rights reserved.