Spatial distribution of cadmium and some biomarkers in Cerastoderma glaucum living in a polluted area

Abstract

Elevated cadmium concentrations were observed at the southern part of Sfax which received direct contamination via water discharge from the crude phosphate treatment plant and indirect contamination by the stock of phosphogypsum. In this area the ecosystem is completely destroyed therefore was necessary for sample collection to move toward the south. In order to determine a spatial distribution of pollution in this area and the consequences of this contamination on the cockles Cerastoderma glaucum, contour maps of cadmium (Cd), metallothionein like protein (MTLP), malondialdehyde (MDA) concentrations and acetylcholinesterase (AChE) activity were established. Contour mapping techniques showed elevated concentrations of Cd, MTLP and MDA in samples from Zarb El Ain toward the south and decreasing concentrations from the coast toward the east. The distribution pattern of AChE activity was opposite to the Cd concentrations. Our results showed that the area studied suffered from severe problems caused by the pollution transported from the phosphate treatment plant by the north–south streams.