Human health risk assessment of potentially toxic heavy metals in the atmospheric dust of city of Hamedan, west of Iran

The atmospheric dust is an important route of human exposure to kinds of pollutants particularly toxic heavy metals. The current study was carried out to assess the ecological and health risk assessment of Co, Cr, and Mn in the atmospheric dust of city of Hamedan, Iran. In so doing, a total of 54 samples of atmospheric dust were collected from the three regions of the study area in 2014. After acid digestion of samples in the laboratory, the Co, Cr, and Mn contents were determined using inductively coupled plasma-optical emission spectrometer (ICP-OES). The results showed that the average contents (mgkg(-1)) of Co, Cr, and Mn in the analyzed samples were 0.23, 0.89, and 8.10, respectively. The results of human health risk assessment showed that ingestion of dust particles is the main exposure route to heavy metals in the dust for the local residents. Also, the upper limit of the 95% confidence interval of hazard indices for non-carcinogenic risks of all analyzed metals in the atmospheric dust was within the safe level (= 1) for both children and adults. The carcinogenic risk levels of Co and Cr were all lower than the acceptable range for local citizens. Based on the results, it can be suggested that special attention be paid to toxic heavy metals that long-term exposure to which via atmospheric dust can have adverse effects on the city resident health.