Correlation between levels of some heavy metals in plants and sediments from a segment of Calabar River and associated creeks in Cross River state of Nigeria

Abstract

Plants and sediments were collected at three sites along Calabar River (CR), Upper Town Creek (UCC) and Lower Town Creek (LCC). The CR is a major tributary of Cross River, Nigeria. The concentrations of 10 heavy metals were determined and results for Fe, Mn and Zn at almost all the sites showed that the levels of these metals exceeded the amounts present in non-polluted areas. Fe was found in the highest concentration at all three sites in both plants and sediments. Correlation analysis between levels of heavy metals in plants and sediments were also determined. The occurrence of higher concentrations of heavy metals in plants and coastal sediments at CR, UCC and LCC is an indication of anthropogenically induced pollution rather than contributions from natural sources.

Keywords:

• Heavy metals
• sediments
• Panicum laxum
• Calabar River
• Nigeria

Acknowledgements

We are grateful to the Aluminum Smelter Company of Nigeria (ALSCON) Laboratory and the University of Uyo, Central Research Laboratory for the analysis of the plant and sediment samples. Dr M. Etesin (ALSCON Research Laboratory) is acknowledged for helpful discussions.