Examination of trace elements in dust and their effects on ecology and public health in Tehran Metropolis (Iran)

This study employed a passive dust sampling method using flat glass traps at 44 locations across Tehran, which allowed for detailed analysis of V, Pb, Cu, Zn, Cd, Ni, and Cr concentrations. It offers an essential understanding of the spatial distribution and seasonal variation of urban dust pollution, along with its associated environmental and human health risks. The results indicate that Zn, Pb, Cu, and Cd are key factors influencing the dust pollution burden in Tehran. The findings highlight the pollution and ecological impacts of dust, showing that most of the dust throughout Tehran has "moderate to high pollution levels" and "considerable ecological risk". In addition, these studies show that Cd and Pb need special attention. Multivariate statistical analyses demonstrated that Cu, Zn, Pb, and Cd were predominantly affected by human activities, while Ni and Cr were affected to a lesser degree, and V appeared to be more influenced by geological sources. The assessment of health risks showed that these levels were within the safe limits (non-carcinogenic < 1 and carcinogenic < 1 ✕ 10^-6), and the possible health risks in children were more than in adults. The most unsafe route of exposure in children was ingestion, followed by dermal contact and inhalation. The findings of this research showed that cold seasons can be most problematic with the negative effects of pollution and ecological risks, and may also have health risks in the long term. The findings pointed to reasons such as increased consumption of fossil fuels, increased traffic, temperature inversion, and atmospheric stability.