Ecological risk assessment of cadmium and lead in urban and forest park soils in Asadabad City, Iran

Contamination of the surface soils of the urban ecosystem with heavy metals poses potential ecological risks. In this research، a preliminary investigation was carried out to evaluate the potential ecological risk of cadmium and lead contamination in urban park soils in Assadabed City، Iran. Soil samples were taken from the urban parks of Asadabad city and analyzed for heavy metals using atomic absorption spectrometry. Based on the concentrations of Cd and Pb in the soils، contamination factor (CF)، contamination degree (Cdeg) and potential ecological risks status (RI) of the soils were calculated. Preliminary results showed a low degree of contamination of urban parks of of Asadabad City. Assessment of the potential ecological risk index (RI) indicated that the cumulative heavy metal contents of the soil do not pose any significant ecological risks. In any case، further analysis of the data showed that the potential ecological risk posed by cadmium was higher than that by lead. The findings indicate that although urban park soils may be polluted due to presence of certain heavy metals، on the whole their ecological risk is insignificant. These findings can help greatly environmental managers in planning، risk assessment and decision-making in the area.