International Journal of Life Science and Agriculture Research

Rhynchophorus phoenicis larvae are a popular dietary protein in the Niger Delta, but oil-industry activities and gas flaring may contaminate their habitats.  Heavy metals like lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn) and copper (Cu) in larvae collected between June–September, 2023 from three sites: Gbarain (industrial, Station A), Tombia village (peri-urban, Station B), and Agudama-Ekpetiama (reference/control, Station C) were quantified. A total of 180 mature larvae (60 per site) were harvested, depurated, oven-dried, digested (HNO₃:HClO₄) and analyzed by atomic absorption spectrophotometry. Morphometrics (30 individuals per station subsample) showed significantly greater length and fresh mass in Gbarain (64.8 ± 5.6 mm; 8.73 ± 1.10 g) than Tombia (58.2 ± 4.9 mm; 7.12 ± 0.95 g) and Agudama-Ekpetiama (61.1 ± 5.0 mm; 7.85 ± 1.02 g) (ANOVA, F ≥ 8.7, p < 0.001). Mean heavy metal concentrations (mg/kg) were highest in Gbarain: Pb 1.86, Cd 0.28, Cr 0.94, Zn 45.2, Cu 6.8; followed by Tombia: Pb 0.95, Cd 0.12, Cr 0.41, Zn 51.6, Cu 5.7; and Agudama-Ekpetiama: Pb 0.42, Cd 0.05, Cr 0.18, Zn 29.7, Cu 3.2. Food safety guidance values were exceeded in Gbarain for Pb (92%), Cd (78%), Cr (85%), Cu (46%) and Zn (10%), while Tombia showed exceedances for Zn (22%), with minimal cases in Agudama-Ekpetiama (≤5%). Elevated Pb and Cd pose potential consumer risks. The findings identify R. phoenicis larvae as sensitive bioindicators of terrestrial contamination and call for routine monitoring and emission control in gas-flaring regions.

Rhynchophorus phoenicis, gas flaring, heavy metals, food safety, health risk.

1. Abdullahi, A. S., Auwal, A., & Usman, A. (2022). Assessment of heavy metal concentrations in selected edible insects consumed in parts of Nigeria. Journal of Environmental Science and Pollution Research, 8(2), 45–54. https://doi.org/10.11648/j.esp.20220802.12
2. Afolabi, T. A., Akinlabi, E. T., Okwu, G. I., & Duru, C. E. (2022). Human health risk assessment of heavy metals in fish species from Niger Delta rivers, Nigeria. Environmental Nanotechnology, Monitoring & Management, 17, 100655. https://doi.org/10.1016/j.enmm.2021.100655
3. Akpoteyon, C., Ezeabasili, A. C. C., & Otobo, I. (2022). Heavy metals contamination in the Nigerian environment: Sources, effects, and management. Environmental Monitoring and Assessment, 194(5), 321–336. https://doi.org/10.1007/s10661-022-09856-7
4. Alimba, C. G., & Bakare, A. A. (2016). Environmental contaminants and their potential genotoxic effects in Nigeria. Environmental Toxicology and Pharmacology, 41, 272–283. https://doi.org/10.1016/j.etap.2015.12.023
5. American Public Health Association (APHA). (2017). Standard methods for the examination of water and wastewater (23rd ed.). Washington, D.C.: American Public Health Association.
6. Banjo, A. D., Aina, S. A., & Salau, T. B. (2012). The nutritional value of fourteen species of edible insects in southwestern Nigeria. African Journal of Biotechnology, 11(30), 7725–7729. https://doi.org/10.5897/AJB11.262
7. Banjo, A. D., Lawal, O. A., & Songonuga, E. A. (2020). Edible insects in Nigeria: Nutritional, ecological, and economic perspectives. Journal of Insects as Food and Feed, 6(4), 365–373. https://doi.org/10.3920/JIFF2019.0058
8. Codex Alimentarius Commission. (2019). General standard for contaminants and toxins in food and feed (Codex STAN 193-1995, Rev. 2019). Rome: FAO/WHO.
9. Codex Alimentarius Commission. (2019). General Standard for Contaminants and Toxins in Food and Feed (CXS 193-1995). Joint FAO/WHO Food Standards Programme. Food and Agriculture Organization of the United Nations.
10. Ekpo, K. E., & Onigbinde, A. O. (2018). Nutritional potentials of the larva of Rhynchophorus phoenicis (F.) consumed in southern Nigeria. International Journal of Food Science and Nutrition, 3(1), 12–18.
11. ERA/FoEN (Environmental Rights Action/Friends of the Earth Nigeria). (2024). Gas flaring in Nigeria: Environmental and health impacts. ERA/FoEN Report, Benin City, Nigeria.
12. European Commission. (2006). Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union, L 364/5.
13. European Commission. (2006). Commission regulation (EC) No. 1881/2006 of 19 December 2006: Setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union, L364, 5–24. Retrieved from https://eur-lex.europa.eu
14. Ezejimofor, M. C., Uche, O. C., Onyenwe, E. C., Oguoma, V. M., Ezeabasili, A. C. C., Ejike, N. C., Oduwole, M. A., Anyanwu, G. O., & Onwubere, B. J. (2018). The burden of oil pollution on health and survival in the Niger Delta region of Nigeria: A narrative review. International Journal of Public Health and Environmental Research, 5(2), 110–124. https://doi.org/10.11648/j.ijpher.20180502.15
15. Giampieri, F., Alvarez-Suarez, J. M., Capanoglu, E., Afrin, S., Prakash, D., Simal-Gandara, J., & Battino, M. (2022). Edible insects: Novel foods for the future. International Journal of Food Sciences and Nutrition, 73(5), 593–603. https://doi.org/10.1080/09637486.2021.1975384
16. Imathiu, S. (2020). Benefits and food safety concerns associated with consumption of edible insects. Nutrition and Food Science, 50(2), 285–296. https://doi.org/10.1108/NFS-07-2019-0228
17. Imathiu, S. (2020). Heavy metal concentrations in edible insects: A review of safety implications. Journal of Insects as Food and Feed, 6(3), 215–226. https://doi.org/10.3920/JIFF2019.0047
18. International Agency for Research on Cancer (IARC). (2012). Arsenic, metals, fibres, and dusts. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans (Vol. 100C). Lyon, France: WHO/IARC.
19. Ite, A. E., Ibok, U. J., Ite, M. U., & Ekanem, A. P. (2023). Petroleum industry activities and environmental degradation in the Niger Delta: Implications for sustainable development. Environmental Challenges, 12, 100663. https://doi.org/10.1016/j.envc.2023.100663
20. Lachat, C., Nago, E., Verstraeten, R., Roberfroid, D., Van Camp, J., & Kolsteren, P. (2018). Eating local, healthy and sustainable: The role of edible insects. Food Security, 10, 201–214. https://doi.org/10.1007/s12571-017-0753-8
21. Musundire, R., Zvidzai, C. J., Chidewe, C., Samende, B. K., & Manditsera, F. A. (2016). Nutrient and anti-nutrient composition of Gonimbrasia belina (mopane worm) harvested from different host trees across Southern Africa. Journal of Insects as Food and Feed, 2(3), 215–223. https://doi.org/10.3920/JIFF2016.0002
22. Nriagu, J. O., Udofia, E. A., Ekong, I., & Ebuk, G. (2016). Health risks associated with oil pollution in the Niger Delta, Nigeria. International Journal of Environmental Research and Public Health, 13(3), 346. https://doi.org/10.3390/ijerph13030346
23. Ogbeibu, A. E., Oribhabor, B. J., Ezenwaka, I. C., Odiete, W. O., Adebayo, O. T., & Akintola, S. L. (2019). Heavy metal concentration and human health risk assessment of some selected fishes from Warri River, Niger Delta, Nigeria. Applied Water Science, 9, 146. https://doi.org/10.1007/s13201-019-1046-7
24. Okoro, J. K., & Ani, G. (2020). Gas flaring and environmental health challenges in the Niger Delta. Journal of Environmental Science and Public Health, 4(1), 34–45. https://doi.org/10.26502/jesph.96120123
25. United Nations Environment Programme (UNEP). (2011). Environmental assessment of Ogoniland. Nairobi, Kenya: UNEP.
26. Van Huis, A., Van Itterbeeck, J., Klunder, H., Mertens, E., Halloran, A., Muir, G., & Vantomme, P. (2013). Edible insects: Future prospects for food and feed security (FAO Forestry Paper 171). Rome: FAO.
27. World Health Organization (WHO). (2020). Exposure to lead: A major public health concern (2nd ed.). Geneva: WHO.