Health Risk Assessment of Heavy Metals in the Contaminated Soils of Tehran Province, Iran

Health risk assessment for heavy metals is a suitable technique to environmental planning. Accordingly, soil samples were obtained from three contaminated sites of Tehran Province, Iran. The heavy metals determined by ICP-AES, then health risks calculated for adults and children. The hazard quotient and hazard index values for all heavy metals and pathways were below a safe level in site 1, and all inhabitants were not at non-carcinogenic risk. The HQ of the ingestion pathway in adults and children for site 2 and site 3 were in the following order: Cd>Pb>Cu>Zn. As for adults and children in the three pathways, the HQ values for Pb, Cu and Zn were less than one, meaning that both the adults and children were not at noncarcinogenic risk. The HQ of the ingestion in adults, similarly, HQ of the ingestion and dermal in children for Cd were greater than 1 in 2 and 3 sites, meaning that the Cd was hazard for adults and children. The cancer risk has been calculated based on Pb and Cd. The US Environmental Protection Agency considers acceptable cancer risk within the range of 1×10−6 to 1×10−4. Though insignificant in its values, carcinogenic risk for adults in site 1 (2.722×10- 4), site 2 (6.67×10-4) and site 3 (9.4444×10-4) and for children on site 1 (5.5×10-4), site 2 (2.203×10-2) and site 3 (1.94×10-3) have been higher than the acceptable values. Hence, the cancer risk for children was more than adults.