An assessment of heavy metal contamination in surface sediment using statistical analysis

Abstract

The distribution and accumulation of heavy metals in the sediments, especially those nearest of wastewater discharges of south of Spain, were investigated. Sediment samples from 14 locations were collected and characterised for metal content (e.g. Ni, Cu, Zn, Cr, Pb, Mn, Cd and Hg), organic carbon, total nitrogen, total phosphorous, n-hexane-extractable material, carbonates and grain size. Concentration data were processed using correlation analysis and factor analysis. The correlation analysis of concentrations data showed important positive correlations among organic carbon, total phosphorus, Cu, Zn, Cd and Hg, otherwise weak correlations among Mn, Cr, Ni and CO(3) (2-), indicating that these metals have complicated geochemical behaviours. The use of statistical factor analysis also confirmed these results. Sediments pollution assessment was carried out using geoaccumulation and metal pollution indexes (MPI(8)). The results revealed that sediments of Cádiz bay and Sancti Petri channel were uncontaminated with the studied metals.

Fecal Pollution in Coastal Marine Sediments from a Semi-Enclosed Deep Embayment Subjected to Anthropogenic Activities: An Issue to Be Considered in Environmental Quality Management Frameworks Development

“…Finally, OM, TN, and TP levels in sediments from the Bay of Algeciras (Table 1) were within the range found in several studies from the Strait of Gibraltar area (Estacio et al, 1997;Rodríguez-Barroso, 2003;Guerra-García and García-Gó mez, 2005;Rodríguez-Barroso et al, 2009). .…”

“…Highest TN peaks were located at S4.1, S5.2, S6.1, and H1. Nutrient affinity for fine particles (Horowitz, 1991) leads to accumulation in depositional areas along with muddy sediments (Rodríguez-Barroso et al, 2009). TP levels ranged from 133 to 922 (median, 511) mg/kg.…”

Concentration, enrichment and distribution of heavy metals in surface sediments of the Tangier Bay, Morocco

“…However, according to the low EF values detected, the MPI values are relatively low and cannot be considered as alarming data. In these areas the metal concentrations are higher than those recorded by Rodríguez-Barroso et al (2010) in sediments from southern Spain, with average MPI values of 15.3 (Cádiz Bay) and 19.3 (a marsh area). Cluster analysis (Fig.…”

Thermal Analysis as a First Screening Method to Evaluate Potential Contamination

“…This index has been used by different authors and applied in marine sediments (Usero et al 2000;Gracia et al 2003;Khaled et al 2006;Rodríguez-Barroso et al 2009b). MPI is calculated according to Usero et al (2000) with the formula:…”

“…The MPI values of six heavy metals (Cd, Cu, Cr, Ni, Zn, and Pb) obtained in a previous work (Rodríguez-Barroso et al 2009b) for sediments of the area under investigation are summarized in Table 3. The lowest MPI values were recorded at stations 3, 4, 7, 10, and 12 (MPI <13.5) in agreement with the sandy sediments they are located on the left of the Cartesian diagram.…”