Potentially Toxic Metals and Polycyclic Aromatic Hydrocarbons Composition of some Popular Biscuits in Nigeria

Evaluation of levels of potentially toxic metals (PTMs) and polycyclic aromatic hydrocarbons (PAHs) were carried out in six biscuit samples commonly consumed in Nigeria. This was done to establish the consumption safety of the biscuits with respect to the amounts of PTMs and PAHs contained. Profiling of As, Cd, Co, Cu, Mn, Pb and Zn in the acid digested biscuit samples was done using Atomic Absorption Spectrometer, while identification and quantification of the various PAHs in the extracts obtained with the aid of a Soxhlet extractor using n-hexane as the extracting solvent were achieved using Gas Chromatograph coupled with Flame Ionization Detector (GC-FID). Potentially toxic metals were detected at levels that ranged from 0.050 to 2.525 mu g/g, while the PAHs concentrations ranged between below detection limit and 19.440 mu g/g. For carcinogenic risk indices of the PAHs, total dietary daily intake (SDDI in mu g/day) ranged from 0.011 in B1 to 0.315 in B6; SDDI for carcinogenic PAHs (mg/day) ranged from 0.001 in B3, B4, and B6 to 0.007 in B2, while the carcinogenic toxic equivalent (TEQ) values (mu g/ g) ranged from 0.006 in B4 to 0.089 in B2. Health risk indices evaluated for both PAHs and PTMs indicated that consumption of the biscuit products as occasional in-between meals and snacks might not constitute serious health problems.