Heavy metal contamination in street dusts and soils under different land uses in a major river basin in an urbanized zone of Aegean region, Turkey.

BACKGROUND

Meles River is one of the major Zn, Cr, Cu, Ni and Pb sources that enter Izmir inner Bay. However, the impacts of land uses on the river's catchment basin has not been investigated before. The study aims to exhibit the impacts of various land uses located on the catchment basin of the river. Cr, Cu, Pb, Ni and Zn concentrations were determined to present the current situation. In addition, the correlation analyses were performed in order to identify the metals' possible sources in the city.

METHODS

Soils and street dusts from the sites representing industrial, residential, and commercial areas and the roads in Meles River basin were sampled and heavy metal levels were determined by using the aqua regia digestion. The correlations among the analytical parameters and the factors loaded with clusters of parameters identified by Principal Component Analysis were used to describe the major sources of studied elements The contamination assessment was also done by using the geoaccumulation index ( and enrichment factor (EF) values.

RESULTS

Ni concentrations (average 697 mg kg) in soils were higher than the levels in street dusts (average 548 mg kg). Dust samples contained 131 mg kg Pb, 179 mg kg Cr, 347 mg kg Cu, and 241 mg kg Zn, while the average values of these metals were detected in lower levels in soils. The average values were found as 114 mg kg, 125 mg kg, 143 mg kg, and 129 mg kg, for Pb, Cr, Cu and Zn, respectively. The main component of soil heavy metals was determined as geochemical background enriched with long-term industrial depositions. Similarly, industrial emissions were found to be the major influence on the heavy metal levels in street dusts.

CONCLUSIONS

Soil and street dust heavy metal levels are significantly affected by emissions from intense industrial activities and traffic emissions, and heavy metals are transported between these two matrices by exchanging masses between each other.