Levels and Health Risks of Heavy Metals in Oryctes owariensis Larvae from Gas-Flaring Communities in Rivers State

Richard Otayoor Abalist¹ and Rosemary Boate Ukoroije²

¹ Lecturer, Department of Biological Sciences, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.

² Associate Professor, Department of Biological Sciences, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.   

Abstract

Oryctes owariensis larvae are a widely consumed protein source in Nigeria, yet oil exploration and gas flaring in the Niger Delta may compromise their safety. This study quantified Pb, Cd, Cr, Zn and Cu in larvae from Obelein community (gas-flaring site) and a rural control site (Okana farm land) using AAS. Mean concentrations (mg/kg) in larvae were Pb 2.87 ± 0.42, Cd 0.94 ± 0.15, Cr 1.55 ± 0.22, Zn 12.6 ± 1.87 and Cu 6.8 ± 0.94, all significantly higher (p < 0.05) than control values (Pb 0.42 ± 0.08, Cd 0.11 ± 0.03, Cr 0.38 ± 0.06, Zn 7.4 ± 1.03, Cu 4.1 ± 0.72). Pb and Cd exceeded FAO/WHO permissible limits, with Hazard Quotients >1 for children, indicating potential non-carcinogenic risks. Findings show that gas flaring contributes to metal deposition in terrestrial food chains, with implications for food safety and public health. The larvae serve as effective bioindicators of soil contamination, but consumption from polluted areas may elevate long-term health risks. Regular biomonitoring, flaring regulation and consumer awareness are recommended.    

Keywords: Oryctes owariensis, Gas flaring, Heavy metals, Obelein, Okana, Food safety, Health risk

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