European Journal of Nutrition & Food Safety

Introduction: Freshwater and marine ecosystems within the Niger Delta are vulnerable to oil spills, pipeline leaks, and wastewater discharge from oil exploration activities. These events can introduce a range of contaminants, including heavy metals like lead, cadmium, and mercury, into the aquatic environment. Contamination of seafood by heavy metals poses significant health risks to consumers, particularly in regions impacted by industrial activities.

Aim: The study aimed to evaluate health risks associated with Crabs, Periwinkles and Shrimps in Yokri Community, Delta State.

Methodology: Seafood samples (Crabs, Shrimps and Periwinkles) were procured from the Ogbe-Ijoh Market in Warri, Delta State, Nigeria, on September 26^th, 2023, representing the wet season samples, while dry season samples were collected on the 19^th of March 2024. Aseptic techniques, including the use of sterilized tools and equipment, were employed to handle and transfer the samples during microbiological analysis. Heavy metals and microbiological assessment were done following standard methods. Health risk assessment was done using the United States Environmental Protection Agency risk assessment framework. 

Results: The results showed that mercury, lead, cadmium, and arsenic varied among seafood species with significant implications for human health. Mercury and arsenic levels were below the detection level (<0.001 mg/kg) in all samples during both seasons. Cadmium concentrations in Crabs were 0.16 mg/kg (wet) and 0.41 mg/kg (dry), while in Periwinkles, values were 0.32 mg/kg (wet) and 0.16 mg/kg (dry). Lead levels were 1.33 mg/kg (wet) and 1.63 mg/kg (dry) in Crabs; 1.04 mg/kg (wet) and 1.24 mg/kg (dry) in Periwinkles. Potential Vibrio population in Shrimps were 2.0 x 10⁴ CFU/g and potential Salmonella-Shigella in Crabs was 1.3 x 10⁴CFU/g in the wet season, indicating faecal contamination and associated health risks. Human health risk assessment showed that lead posed the highest risk, with Target Hazard Quotient values exceeding the reference doses in both seasons for Crabs (wet: 0.224, dry: 0.274) and Periwinkles (wet: 0.121, dry: 0.144). Cadmium posed a risk in Periwinkles (wet: 0.0642, dry: 0.0321) and Crabs (wet: 0.0447, dry: 0.112). However, Estimated Daily Intake values did not exceed Provisional Tolerable Daily Intake for cadmium or lead, suggesting minimal health risks.

Conclusion: Health Risk Index analysis confirmed negligible health risks associated with cadmium and lead intake from seafood. However, continuous monitoring and mitigation efforts to ensure seafood safety and protect public health in Yokri and its environs are vital as findings will serve as a warning to local authorities, fishing communities and consumers, emphasizing the need for sustainable practices in this ecologically vital region.