Determination of lead, naphthalene, phenanthrene, anthracene and pyrene in street dust

Street dust is a potential source of lead exposure to humans, however scarce information about the pollution levels with lead and polyromatic hydrocarbons exists in Venezuela, limiting the appropriate evaluation of the levels of risk of the people. This work was aimed in the determination of the concentrations of lead, naphtalene, anthracene, phenanthrene and pyrene in the street dust of the most transited avenues and streets of Maracay city. Thirty street dust samples were collected at the streets and avenues, troll and bus main station. Lead was determined by atomic absorption spectrometry after acid digestion (Pb-total), also the fractions of lead soluble in 1 M MgCl₂ and 0.5 M ammonium acetate (pH = 7) were quantified. The polyaromatic hydrocarbons concentrations were determined by capillary gas chromatography equipped with a flame ionization detector. The Pb-total ranged between 734 and 11.439 μg/g with the higher values at the most transited streets and avenues. About 60 % of samples exhibited concentrations between 1.000 and 2.500 μg/g, similar to the values reported in the literature for soils of urban areas. The fraction of lead soluble in magnesium accounted for less than 3 % of Pb-Total, while the 0.5 M ammonium acetate solution represented more than the 75 % of the total loads of the pollutant. The most contaminated samples were those taken at the toll with concentrations of 695.5 and 252.1 μg/g phenanthrene and anthracene were the most abundant, while at the bus station all compounds were detected.

Keywords
Environment; Polyaromatic hydrocarbons determination; Street dust; Urban pollution