Heavy Metal Contamination of Airborne Dust in the Environment of Two Main Cities in the Eastern Province of Saudi Arabia

Amounts and chemical components of airborne dust in urban city centers are important environmental pollution indicators. High concentrations of heavy metals in the environment result in health hazards including adverse effects on the nervous, blood forming, cardiovascular, renal and reproductive systems. The aim of the present study was to assess the heavy metals contamination of street and ambient airborne dust in two main cities in the Eastern Province of Saudi Arabia. Dust samples were collected from street environment and ambient air at different sites in the selected two cities. The metal composition of dust samples was quantitatively determined by inductively coupled plasma-atomic emission spectrometer. The average concentrations of ambient airborne dust were below the Saudi s air quality criteria of 150μg/m^3, while the average levels of street airborne dust were exceeding the air quality standards of 150 – 350 μg/m^3. Metal concentrations in the street airborne dust were much higher than those of the ambient type. Aluminum (Al) is considered as an index of mineral dust, and during this study, values of metal/Al ratios for street airborne dust were much higher than those of the ambient type. This reflects the high contribution of man-made sources, particularly motor vehicles, in metal composition. Banning of leaded petrol helped in the general decrease of lead (Pb) concentrations in the KSA Eastern Province atmosphere.