Heavy Metal Pollution in Arid Urban Environments: Anthropogenic and Geogenic Insights from Road Dust in the United Arab Emirates.

Abstract

Dust is a significant environmental concern due to its pervasive nature and potential health risks, particularly from heavy metals. This is exacerbated in urban areas, where dust can act as a reservoir for pollutants, posing risks to human health through various exposure pathways. This study aims to explore and compare the distribution of heavy metals in road dust from two distinct cities in the UAE: Dubai, a commercial hub, and Khor Fakkan, a coastal town with industrial activities. Road dust samples were collected from 29 locations in both cities, including areas with varying traffic density, residential settings, and industrial zones. Findings reveal notable levels of Cd exceeding background levels across both regions, with a slightly higher range (18.05-47.99 mg/kg) in Khor Fakkan compared to (13.96-44.03 mg/kg) in Dubai. Similarly, Zn levels peak at 587.88 mg/kg in certain samples in Dubai and reach 1802.02 mg/kg in Khor Fakkan. Principal Component Analysis highlights Co, Fe, Cd, and Zn as primary pollutants in Dubai, while Ni, Cr, Cu, and Co are predominant in Khor Fakkan. Overall, pollution index analyses, including the geoaccumulation index, pollution index, and enrichment factor, underscore Cd, Zn, and Ni as key pollutants across both regions, with hotspots associated with industrial and vehicular emissions. Representative series of the EFs are also presented, emphasizing the average extent of pollution with various heavy metals. Future work should focus on source attribution analyses and risk mitigation strategies to reduce heavy metal pollution in urban environments and protect public health and ecosystems.