The SigniAssessment of Concentrations and Potential Health Risk of Heavy Metals in Biscuits Commonly Consumed by Primary School Children in Choba, Port Harcourt, Nigeria

Biscuits are widely consumed by primary school children as easy snack especially during break-periods in Nigeria and nowadays heavy metals are omnipresent, hence, metals could be picked up in any of the biscuit manufacturing process flow line such as mixing, cutting, baking and packing and thus becoming a potential public health issue. Therefore, the objective of this paper is to assess the concentrations and potential health risk of heavy metals in biscuits commonly consumed by primary school children in Choba, Port Harcourt, Nigeria. The metal concentrations were determined by Solaar Thermo Elemental Atomic Absorption Spectrophotometer, Model SN-SG 710960 after digesting the biscuit samples using a mixture of 0.1 mL of concentrated HNO3, 12.9 mL of water, and 2 mL of H2O2 at 100oC temperature. The mean concentrations (, mg/kg) of heavy metals in the biscuits investigated were Fe: 26.33 ± 0.21; 21.56 ± 0.44; 15.76 ± 0.27; Ni: 0.40 ± 0.042; 0.57 ± 0.022; 0.33 ± 0.014 and Pb: 0.0013 ± 0.002; 0.0014 ± 0.003; 0.001 ± 0.002 for biscuit types A, B and C respectively. These concentration of metals in biscuits from this study were compared against WHO/FAO maximum permissible limits, mg/kg (Fe: 426; Ni: 7.9 and Pb: 0.3) set for biscuits. The results indicate that the levels of iron, nickel, and lead detected in all brand of biscuit were significantly below the WHO/FAO limits. The potential health risk of heavy metals in biscuits commonly consumed by primary school children were further appraised by the estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and lifetime carcinogenic risk (LCR). Data obtained reveals that the EDIs ranged from 6.25×10-7 to 1.6×10-2 mg/kg bw/day, the THQs fluctuated between 1.03 x 10-5 to 5.37 x 10-4, while the HIs varied between 1.42 x 10-3 to 5.39 x 10-4). Values of HI in all biscuit types investigated are less than unity (HI