Identification of hot spot areas associated with potentially toxic elements found in urban dusts and their relation with physical and socioeconomic variables in a semiarid city in northwest Mexico

Abstract:

Rapid industrialization associated with urbanization can increase the content of heavy metals cataloged as potentially toxic elements (PTE) in urban dust and soils. Increased concentrations of PTE in dust particles and soils can be a source of chronic exposure to humans and may result in serious health risks. Urban dust is composed mainly of solid matter (soil minerals, fine or coarse dust, pollen, sea spray, etc.), anthropogenic components derived from road construction (asphalt, concrete), automobiles (tire dust, brake dust, combustion exhaust, and traffic paint) and emissions from industrial processes. Determining the spatial distributions of settled dust and concentrations of PTEs is important in determining exposure risks to the population. In this work, physical and socioeconomic variables were linked to PTE exposure maps to determine areas of more or less vulnerability in a semiarid city in northwest Mexico. Flood and impervious zone maps were used as locations where dusts are accumulated, especially influenced by the summer rains that are characteristic of the North American monsoon (NAM). On the other hand, spatially explicit socioeconomic marginalization and air quality related mortality maps were used to create vulnerability maps. The hot spot analysis (Getis-Ord) technique was used to integrate the physical, socioeconomic, and heavy metal distribution maps. Furthermore, a sensitivity analysis revealed the influence of each layer on the final vulnerability map. The resulting hot spot analysis is an effective planning tool that allows the identification of vulnerable zones in the city and can assist decision makers in preventing health issues and land use urban planning.