Contamination and chemical fractionation of heavy metals in street dust from the Metropolitan Area of Monterrey, Mexico

• Published in: Environmental technology Vol. 32; no. 10; pp. 1163 - 1172
• Main Authors: Valdez Cerda, Enrique, Hinojosa Reyes, Laura, Alfaro Barbosa, Juan Manuel, Elizondo‐Martinez, Perla, Acuña‐Askar, Karim
• Format: Journal Article
• Language: English
• Published: Abingdon TF 01-07-2011; Taylor & Francis Group; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Applied sciences; Cadmium; Cadmium - analysis; Chemical Fractionation; Chromium; Cities; Cluster analysis; correlation; digestion; Dust; Dust - analysis; emissions; environmental technology; Exact sciences and technology; Fractionation; heavy metal; Heavy metals; lead; Lead (metal); Lead - analysis; Metals; Metals, Heavy - analysis; Metropolitan Area of Monterrey; Mexico; multivariate analysis; nickel; Pollution; principal component analysis; Principal components analysis; risk; Samples; sequential extraction; Statistical methods; street dust; Streets; Studies; Transportation; United States Environmental Protection Agency; zinc; Mexico; British Isles; Cluster analysis; Correlation coefficient; street dust; Pollutant behavior; Mobility; Sequential extraction; Motor vehicle; Urban area; Multivariate analysis; Pollutant emission; Metropolitan Area of Monterrey; Contamination; Heavy metal; Dust; Lead; Air pollution; Street; Road traffic; Speciation; Principal component analysis
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2010.529466

The prevalence of heavy metal pollution and mobility of both Pb and Cd was investigated in street dust samples from the Metropolitan Area of Monterrey (MAM) in northern Mexico. Street dust samples from 30 selected sites were analysed for their content of Zn, Cd, Pb, Cr and Ni after digestion according to US EPA Method 3051. Multivariate analysis including correlation coefficient analysis, Principal Component Analysis and Cluster Analysis was used to analyse the data and identify possible sources of these heavy metals. Compared with background values, elevated concentrations of Pb (300 mg kg⁻¹), Cd (7.6 mg kg⁻¹) and Cr (78 mg kg⁻¹) were observed in street dust of MAM. Based on multivariate statistical approaches, the studied elements were classified in three main sources: (1) Cr, Ni and Zn mainly derived from industrial activities; (2) Cd originating from traffic‐related activities; and (3) Pb associated with vehicular emissions. A sequential extraction procedure using the Tessier method was applied to evaluate the mobility of Pb and Cd in street dust. The majority of Pb was associated with the residual fraction followed by the carbonate fraction. The majority of Cd was associated with the residual fraction. These results indicated that the mobility was higher in Pb (26%) compared with Cd (11%), posing a potential risk to the environment.