Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8913541 | Journal of African Earth Sciences | 2018 | 35 Pages |
Abstract
This study deals with the assessment of the behaviour of seven heavy metals (Cd, Zn, Cu, Pb, Ni, Cr and As) in streambed sediments within the Gabes Catchment, located in South-eastern Tunisia. To understand the effect of intense human activities in the Gabes Basin on the quality of the environment, 22 sediment samples, spread all over the study basin, were taken and analyzed for heavy metals. Heavy metal concentrations were shown to vary in the following order: Znâ¯>â¯Pbâ¯>â¯Cuâ¯>â¯Crâ¯>â¯Niâ¯>â¯Cdâ¯>â¯As. Sediment quality was assessed based on the evaluation of various indices. A total of 27% of the sampling stations are characterised by sediment Enrichment Factors (EF) exceeding 40, reflecting extremely severe pollution. This result was also confirmed by different indices, including Sediment Pollution Index (SPI), Pollution Load Index (PLI) and Geo-accumulation index. The calculation of Mean Effect Range-Median Quotient (M-ERM-Q) indicated that in stream discharge, all metals have a probability of 21% to be toxic. The ecological toxicity risk of heavy metals increases close to urban (traffic activity) and industrial activities (industrial complex of Gabes). Close to Gabes City, the situation and the degree of contamination that may be transferred into marine ecosystems is worrisome and requires immediate intervention.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geology
Authors
Noura Dahri, Abdelfattah Atoui, Manel Ellouze, Habib Abida,