The toxic footprint of lead exposure: oxido-inflammatory biomarkers in urban populations of Niger Delta, Nigeria.

Lead (Pb) exposure is still a major public health concern in southern Nigeria's urban and industrial areas. This study examined the relationship between blood lead levels (BLLs) and biomarkers related to oxido-inflammatory, antioxidant, renal, and apoptosis in adult residents of Port Harcourt, Aba, and Owerri. Atomic absorption spectrophotometry was used in this cross-sectional study to detect lead in venous blood samples. Biomarkers, including malondialdehyde (MDA), heme oxygenase-1 (HO-1), reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), interferon-gamma (IFN-γ), kidney injury molecule-1 (KIM-1), and caspase-3 (CASP3), were quantified using standard spectrophotometric and enzyme-linked immunosorbent assay (ELISA) methods. ANOVA, t-tests, Kruskal-Wallis tests with post-hoc comparisons, and Spearman correlation (α = 0.05) were among the statistical analyses performed. Aba had higher mean BLLs (2.8-4.2 µg/dL), which varied significantly between cities (p < 0.05). BLLs showed significant positive correlations with MDA (ρ = 0.39), HO-1 (ρ = 0.41), IFN-γ (ρ = 0.36), and KIM-1 (ρ = 0.42) (p < 0.05), suggesting increased oxidative stress, inflammatory response, and early renal involvement. The majority of sex-based differences were not statistically significant (p > 0.05), while antioxidant indicators showed inconsistent patterns. In regions with greater BLLs, CASP3 levels were slightly elevated. Measurable changes in oxidative, inflammatory, and renal indicators were linked to elevated BLLs. These results highlight the necessity of more stringent environmental monitoring and focused public health initiatives to lower lead exposure in Nigerian urban populations.