Evaluation of Heavy Metal Contents and Their Estimated Daily Intakes from Beans Cake (Akara) Commonly Consumed Within Afikpo Metropolis, Nigeria

Abstract

This study examined the contents of some heavy metals and their estimated daily intakes from beans cake (popularly called akara) commonly consumed within Afikpo Metropolis, Nigeria using the Atomic Absorption Spectrophotometry (AAS). The results indicate that the concentration of the heavy metals (mg/Kg) varied across the various samples. The samples (labelled A1, A2, A3, A4 and A5) were purchased from five different outdoor vendors within Afikpo Metropolis; was ground into powdered, sun-dried for 12 hours, subjected to acid digestion and then analysed for the selected trace metal (Ni, Cu, Pb, Fe, Al and Zn) contents using calibrated atomic absorption spectrophotometer following standard analytical procedures. Results of the analysis revealed that the metal concentrations of Ni in mg/kg has the least value of 0.06±0.04 in sample A2 and the highest value of 0.27±0.06 in sample A4 the Cu has the least value of 0.31±0.10 in sample A4 and the highest value of 1.28±0.28 in sample A1; Pb has the lowest value of 0.04±0.01 in sample A4 and Pb has the highest value of 0.49±0.04 sample A3; Fe has the least value of 2.00±0.10 in sample A5 and with the highest value of 6.23±0.21 in sample A4; Al has the least value of 0.92±0.08 in sample A2 and the highest value of 3.23±0.29 in sample A5 and Zn recorded the least value of 2.06±0.06) and the highest value of 5.16±0.19 in sample A1. Similarly, the estimated daily dietary intake (mg/kg body weight) from the respective in sample A1 to A5 for a 70 kg body weight were in the range 3.9E-4 to 9E-5; 1.83E-3 to 4.4E-4; 7.0E-4 to 6E-5; 8.90E-3 to 2.86E-3; 4.61E-3 to 1.31E-3 and 7.37E-3 to 2.94E-3 for Ni, Cu, Pb, Fe, Al and Zn respectively. The results thus showed that only Pb, Al and Ni were above WHO permissible limits and consequently, estimated daily intake risk factor increased as Fe < Zn < Cu < Al < Ni < Pb. The presence of some of these metals can be attributed to the various human activities, vehicular emission storage containers, methods and ingredients used in the preparation. That notwithstanding, the results indicate that consumption of these roadside bean cake may not pose and serious health threat.