Effect of contaminated soils with lead, zinc, and cadmium and their related dust effect on air pollution in Isfahan (Iran)

Aims: The purpose of this research was to determine the effects of soils contaminated with lead, zinc and cadmium on the high concentration of these metals in the urban air. Materials and Methods: In this regard 63 samples of soil and 18 air samples were taken at sampling grids from various regions of the city. After digestion of samples, the extracted liquids were analyzed by atomic absorption spectroscopy. Results: The concentration of lead, zinc, and cadmium in the soil samples were not higher than international standards, but was two to three times as high in the air as that found in European countries and U.S. Results also showed a correlation between concentration of these metals in the city soils and their increased level in the city air through dust and wind, particularly in the northern parts of the city, whilst no such correlation is found in the southern parts, which could be due to wind blowing dust polluted with these metals from heavy industries located at south-west of Isfahan. Conclusion: As, at present time, there is a ban on consumption of leaded petrol throughout the city, two main probable sources of lead pollution in the air of the city of Isfahan are dust from contaminated soil and also, presence of a large steelworks industry in the south-west of Isfahan which is in the direction of south-west to north-westerly winds.