Assessing metals and metalloids impact of roadside dust on human health in Osogbo, Osun state, Nigeria

Metals and metalloids in roadside dust pose considerable threats to both human health and the environment. This study assesses human health risks of metal exposure to roadside dust by conducting a health risk assessment (HRA) for metals and metalloids uptake rates for children and adults via exposure pathways. Settled dust samples were collected from the major roads in Osogbo, Osun state. These samples were subjected to standard laboratory procedures for metals and metalloids analysis using Atomic Absorption Spectroscopy (AAS). All the metals and metalloids except Cd had their concentration below the WHO limit. The average concentration of Cd was 1.54 mg kg-1, significantly above the WHO guideline of 0.80 mg kg-1, indicating a possible health concern. A strong positive correlation exits between Ni and Cd (.774 ⁎⁎ ) (p<0.01), Pb (.662 ⁎⁎ ) (p<0.01), Zn (.606 ⁎⁎ ) (p<0.01), and As (.549*) (p<0.05), showing that greater Ni concentrations are associated with higher concentrations of Cd, Pb, Zn, and As. Two principal components were identified, accounting for 80% of the overall variation. PC1 has an eigenvalue of 60.834; however, PC2 has a higher eigenvalue of 74.952, implying that PC2 explains more of the variation in the data than PC1. Non-carcinogenic risk evaluations identify possible health risks linked with Cu, Cd, Cr, and As exposure, primarily through inhalation routes. Carcinogenic risk showed that Cd demonstrated high CR values ranging from 3740 to 1.30*10 12 for adults and children throughout the study's various exposure paths. This study offered significant insight into the metals and metalloids pollution status in Osogbo, Nigeria, employing data and statistics, highlighting the need for evidence-based actions for environmental preservation to safeguarding people's health.