Spatial assessment and source identification of trace metal pollution in stream sediments of Oued El Maadene basin, northern Tunisia.
Environ Monit Assess
; 188(7): 397, 2016 Jul.
Article
in En
| MEDLINE
| ID: mdl-27270485
ABSTRACT
An extensive spatial survey was conducted on trace metal content in stream sediments from Oued El Maadene basin, northern Tunisia. Our objectives were to evaluate the level of trace metal pollution and associated ecological risk and identify the major sources of metal pollution. A total of 116 stream sediment samples were collected and analysed for total As, Cd, Cr, Cu, Ni, Pb, V, Zn, and Zr concentrations. The results showed that concentrations of Cr, Ni, V, and Zr were close to natural levels. In contrast, As, Cd, Cu, Pb, and Zn had elevated concentrations and enrichment factors compared to other contaminated regions in northern Tunisia. Ecological risk to aquatic ecosystems was highlighted in most areas. Principal component analysis showed that Cr, Ni, V, and Zr mainly derived from local soil and bedrock weathering, whilst As, Cd, Pb, and Zn originated from mining wastes. Trace metals could be dispersed downstream of tailings, possibly due to surface runoff during the short rainy season. Surprisingly, Cu, and to a lesser extent As, originated from agricultural activities, related to application of Cu-based fungicides in former vineyards and orchards. This study showed that, despite the complete cessation of mining activities several decades ago, metal pollution still impacts the local environment. This large pollution, however, did not mask other additional sources, such as local agricultural applications of fungicides.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Trace Elements
/
Environmental Monitoring
/
Geologic Sediments
/
Environmental Pollution
Type of study:
Diagnostic_studies
/
Prognostic_studies
Aspects:
Determinantes_sociais_saude
Country/Region as subject:
Africa
Language:
En
Journal:
Environ Monit Assess
Journal subject:
SAUDE AMBIENTAL
Year:
2016
Document type:
Article
Affiliation country:
Túnez