Geochemical, geospatial, geoenvironmental and potential human health risk associated with dust particles in major roadsides in ado ekiti, Nigeria

Abstract

Heavy metal contamination in road dust poses significant health risks through ingestion, skin absorption and inhalation. This study examines the concentrations of eight heavy metals – nickel (Ni), cadmium (Cd), lead (Pb), chromium (Cr), zinc (Zn), copper (Cu), arsenic (As) and manganese (Mn) in road dust samples from Ado-Ekiti, Nigeria. It assesses the associated ecological and health risks. Sixty samples were randomly collected at 300-meter intervals from a key roadside and the locations were mapped using QGIS. The samples were analyzed for heavy metals using atomic absorption spectrometry (AAS). Contamination and enrichment factor analyzes identified Cd as the most contaminated element, mainly influenced by anthropogenic activities. Geodata analyzes revealed higher levels of cadmium and lead in certain areas. Principal component analysis (PCA) explained 80.28% of the data variance, with the first component indicating contamination by Ni, Pb, Zn, Cu, As, and Mn. At the same time, the second was associated with Cd and Cr. Among metals, the daily intake of zinc (Zn) was the highest at 4.23E + 03 mg/(kg·day), followed by Mn, Cu, Pb, Cr, Cd, Ni and As. Dermal absorption showed similar trends, with Zn leading the way at 1.95E + 03 mg/(kg·day). The non-carcinogenic hazard indices for ingestion and dermal absorption exceeded the safe limits for Cd and Pb, while the carcinogenic risk was highest for Cd (9.56E + 06) and lead (1.42E + 07). This study highlights the urgent need for targeted interventions to combat heavy metal contamination and protect public health.