Study of heavy metal levels in indoor dust and their health risk assessment in children of Ahvaz city, Iran

The concentration of heavy metals in household dust and their health risks on children living in different areas of Ahvaz city was investigated during November 2013 to October 2014 in Iran. Totally, 108 dust samples were taken from their houses in three different areas including S-1 (industrial), S-2 (heavy traffic) and S-3 (residential zone far away from industrial and traffic emission sources). The samples were analyzed for eight selected heavy metals (Cr, Ni, Cu, Mn, Pb, Zn, Co and Cd) using an inductively coupled plasma optical emission spectroscopy (ICP-OES, Spectro Arcos Model, Germany). Exposure and risk assessment of these metals were estimated using USEPA's exposure parameters. Results showed that the mean values of all heavy metals in tempered months were significantly higher than the other months (p<0.05). Cancer risk and non-carcinogenic risk (hazard index) of Ni, Cr, Cd and Pb from indoor dust exposure were estimated for children via three exposure pathways (ingestion, inhalation and dermal contact). The non-cancer risks to children in all samples were lower than acceptable level of 1, while the potential cancer risks from Ni intake in S-1 and S-2 were 1.57E-06 and 1.19E-06, respectively, and for Cr in S-1 and S-2, it was 1.43E-06 and 1.15E-06, respectively, which these values were slightly higher than the acceptable level (1x10(-6)). In conclusion, household dust of Ahvaz city would probably have a significant potential to cause cancer in most exposed children.