Evaluation of pollution and potential ecological risk of dusts contaminated with toxic elements, the case of residential buildings in Isfahan metropolis, Iran

Air pollution is a major contributor to chronic respiratory and cardiovascular diseases, resulting in an estimated annual premature death toll of 6.2 to 8.4 million individuals. The objective of this study is to investigate the concentration of potentially toxic elements in dust collected from residential complex in Isfahan during the winter (2022-2023). To ensure comprehensive coverage, 31 residential residential complex were chosen across the entire Isfahan City. Dust samples were collected in triplicate (totaling 93 samples) from from the internal surfaces of the ground or first floor of residential complexes, except for common spaces. The samples were transferred to the laboratory and the concentrations of Lead, Cadmium, Arsenic, Zinc, Cobalt, Nickel, Copper, Chromium, and Vanadium were then measured using an ICP-OES device, model Optima 83. The average concentrations of Arsenic, Cadmium, Nickel, Manganese, Cobalt, Lead, and Vanadium in the collected samples were found to be 5.55, 0.95, 32.6, 241, 3.87, 300, and 30.6 mg/kg, respectively. According to the enrichment factor analysis, the concentrations of Lead and Cadmium were of non-natural and anthropogenic sources in all sampling stations except for West Allameh Amini. A notable positive correlation was observed between the Lead enrichment factor and the traffic index at a 95% confidence level (p-value=0.021, r= 0.369). Similarly, a significant strong positive correlation was found at a 99% confidence level between the ecological risk assessment index and the traffic index (Pvalue=0.00, r= 0. 619). This suggests that traffic has a major impact on the concentration of potentially toxic elements at the sampling stations.