SEASONAL-VARIATIONS OF HEAVY-METALS IN SEDIMENTS AND AQUATIC MOSSES FROM THE CAVADO RIVER BASIN (PORTUGAL)

• Type: Article in International Scientific Journal
• Date: 1994

Authors

goncalves, epr (Author) Other; soares, hmvm (Author) FEUP; boaventura, rar (Author) FEUP; machado, aasc (Author) FCUP; dasilva, jcge (Author) FCUP

Journal

Title: Science of the Total Environment

Vol. 142 No. 142

Pages: 143-156

ISSN: 0048-9697

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 58 Citations

Scopus - 67 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-001-K9G

DOI: 10.1016/0048-9697(94)90322-0

Abstract (EN): Concentrations of Cd, Cr, Cu, Ni, Pb and Zn in surface sediments and aquatic mosses from the Cavado river basin were determined in order to evaluate the overall metal contamination and trace the main pollution sources. The natural background levels were calculated for both plants and sediments (fraction < 63 mum) collected at uncontaminated sites and concentrations were normalized to the natural levels. The maximum resulting contamination factors in the aquatic mosses ranged from 6 (Zn) to 101 (Cr). In the sediments the accumulation rates are lower, between 3 (Zn) and 18 (Pb). The degree of contamination was also evaluated by calculating a metal pollution index and the more polluted reaches were identified. Metal concentration variations in plants and sediments in two different surveys ( 1988 and 1989) were studied by factor analysis. Three factors are sufficient to characterize data variance. Factors corresponding to plants and sediments show different metal composition and provide evidence that industrial effluents and drainage waters from a mining area are the main causes of variations of element concentrations. The seasonal variations of metal concentrations both in plants and sediments are also discussed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 14