Ecological Risk Profiles of Heavy Metals and Polycyclic Aromatic Hydrocarbon in Soil Around Selected Industries in Ilorin, Nigeria

Heavy metals and polycyclic aromatic hydrocarbons (PAHs) posed ecological risks in soils surrounding industrial areas in Ilorin, Nigeria. Soil samples were collected from nine selected industries, analyzed for cadmium, copper, chromium, iron, and lead using Atomic Absorption Spectrometry. Pollution and ecological risk levels were evaluated using standard indices, including Enrichment Factor, Geo-accumulation Index, Pollution Load Index, and Potential Ecological Risk Index (RI). The QuEChERS extraction method was applied for PAH analysis, and the presence of 16 EPA-priority PAHs was determined using gas chromatography–mass spectrometry. Results showed varying concentrations of heavy metals across all sites, indicating widespread contamination. Some of the sampled locations exhibited moderate contamination, suggesting potential ecological risks. Soils around metal and steel industries were the most impacted, with RI values ranging from 198.46 to 207.53, followed by automotive industries (127.05–190.57). The least impacted soils were associated with wood and furniture industries, with RI values between 129.75 and 145.44. Heavy metals posed moderate ecological risks, particularly in areas near metal and steel industries. Traces of priority PAHs -naphthalene and anthracene were detected at 0.53 ng/g in soil from an automobile workshop, indicating anthropogenic influence. Regulatory monitoring and improved waste management practices are recommended to reduce soil contamination.