Contamination Factor, Metal Pollution Index and Estimated Daily Intake of Heavy Metals in Some Selected Energy Drinks in Nigeria

This study assessed the levels of selected heavy metals and their associated health risks in commercially available energy drinks using contamination indices. A total of thirty (30) energy drink samples comprising twenty-three (23) liquid formulations and seven (7) powdered formulations were collected from retail outlets and analyzed for cobalt (Co), chromium (Cr), cadmium (Cd), arsenic (As), nickel (Ni), and lead (Pb). Liquid samples were digested using aqua regia and analyzed by Atomic Absorption Spectrophotometry (AAS), while powdered samples were prepared as pellets and analyzed using X-ray Fluorescence (XRF). The contamination status of the metals was evaluated using Contamination Factor (CF), Metal Pollution Index (MPI), and Estimated Daily Intake (EDI) for both adults and children. Results showed that several samples contained elevated concentrations of heavy metals above recommended limits, particularly cadmium, nickel, and lead. The highest concentrations were observed in powdered samples such as EJ and KR, with lead values of 0.2092 mg/L and 0.1754 mg/L, respectively, and arsenic levels of 0.0451 mg/L and 0.0316 mg/L. Contamination factor analysis indicated high contamination for cadmium in nearly all samples, while lead contamination was markedly elevated in all detected samples. The metal pollution index ranged from 0.12 to 4.06, with sample EJ recording the highest overall metal burden, indicating significant multi-metal contamination. Estimated daily intake values revealed that children had higher exposure levels than adults due to lower body weight, and the EDI values of cadmium, nickel, and lead in many samples exceeded permissible tolerable daily intake limits. The findings suggest that regular consumption of some energy drinks may pose potential public health risks, particularly to children and frequent consumers. Continuous monitoring, stricter regulatory control, and improved manufacturing quality assurance are therefore recommended to minimize heavy metal contamination in energy drink products.