Toxicant-Induced Oxidative Stress and Pregnancy Outcomes: A Study of Pregnant Women Exposed to Artisanal Refinery Emissions in Delta State

Background: Artisanal crude oil refining ("Kpo fire") is widespread in the Niger Delta, releasing substantial amounts of particulate matter, heavy metals, and polycyclic aromatic hydrocarbons. Pregnant women residing in these host communities face an elevated risk of severe oxidative stress, which may contribute to adverse pregnancy outcomes. Objective: To investigate the association between toxicant-induced oxidative stress and pregnancy outcomes among pregnant women exposed to artisanal refinery emissions in Delta State.

Methods: A comparative cross-sectional study was conducted with 250 pregnant women, comprising 125 from three artisanal refinery host communities in Warri South LGA and 125 from non-exposed control communities in Ika North LGA. Venous blood samples were evaluated for malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), as well as serum lead and cadmium levels. Antenatal care (ANC) records were utilized to document pregnancy outcomes, including birth weight, gestational age at delivery, preeclampsia, and miscarriages. Data analysis was performed using SPSS version 26, employing independent t-tests, chi-square tests, and logistic regression models (significance set at p < 0.05). Results: Exposed participants exhibited significantly higher mean concentrations of MDA (4.82 ± 1.14 versus 2.91 ± 0.87 μmol/L , p < 0.001 ) and lead (18.4 ± 5.2 versus 7.1 ± 2.8μg/dL, p < 0.001), alongside depleted antioxidant markers (SOD and GSH). Adverse pregnancy outcomes were significantly elevated in the exposed cohort: low birth weight (28.0% versus 12.8%, p = 0.002), preterm birth (22.4% versus 9.6%, p = 0.005), and preeclampsia (16.8% versus 6.4%, p = 0.009). Elevated oxidative stress and serum lead levels emerged as significant independent predictors of low birth weight (OR = 2.87, 95% CI: 1.42 - 5.81). Conclusion: Emissions from artisanal crude oil refining induce severe oxidative stress and correlate strongly with adverse pregnancy outcomes. These findings underscore the urgent need for targeted public health interventions and sustainable alternative livelihood programs in affected regions.