TITLE:
Dietary Exposure and Human Health Risk Assessment of Toxic Metals in Marketed Crayfish (Procambarus clarkii) from the Niger Delta Region of Nigeria
AUTHORS:
Adedoyin Olubunmi Bankole, Nelson Obire, Ekaette Akpan Fadairo, Godwin Johuel Birma, David Niyi Olowoyo, Adebayo John Alegbemi, Bamidele Honesty Akpeji
KEYWORDS:
Toxic Metals, Procambarus clarkii, Seasonal Variation, Health Risk Assessment, Nigeria
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.4,
April
21,
2026
ABSTRACT: Crayfish is widely consumed in Nigeria and may accumulate toxic metals from polluted aquatic environments, particularly in oil-producing regions of the Niger Delta. This study evaluated the concentrations and potential human health risks of selected toxic metals in the edible tissues of Procambarus clarkii obtained from Ogbe-Ijoh Market, Delta State, Nigeria. Samples were collected from ten vendor-linked crayfish consignments representing source communities supplying Ogbe-Ijoh Market during the dry and wet seasons and analysed for cadmium (Cd), lead (Pb), nickel (Ni), and chromium (Cr) using atomic absorption spectroscopy (AAS) following standard acid digestion procedures. Pollution index (PI), target hazard quotient (THQ), hazard index (HI), and cancer risk (CR) were computed to assess potential health risks. In the dry season, metal concentrations (mg·kg−1) ranged from 4.3 - 39.5 for Pb, 1.4 - 14.2 for Ni, and 2.8 - 23.5 for Cr, whereas wet-season concentrations ranged from 3.7 - 55.4 for Pb, 0.5 - 5.9 for Ni, and 2.7 - 10.4 for Cr. Cadmium was below the detection limit in all samples. Lead exhibited the highest concentrations in both seasons. PI values exceeded unity (PI > 1) across sampling locations, indicating contamination. THQ and HI analyses identified Pb as the principal contributor to non-carcinogenic risk, particularly during the wet season, with higher exposure indices observed in children. Estimated cancer risk values for Pb exceeded acceptable limits at several locations. The elevated Pb concentrations and associated health risk indices underscore the need for continuous environmental monitoring, stricter pollution control measures, and public awareness regarding crayfish consumption in oil-impacted communities. Regular surveillance of toxic metals in commonly consumed aquatic foods is essential to safeguard public health in the Niger Delta region.