Assessment of Human Health Risk of Potential Toxic Metals in Herbal Concoction Teas Commonly Consumed in Nigeria

Concentrations of potential toxic metals (Pb, Cr, Cu, Zn, Ni, Co, As, Fe and Mn) were determined in herbal concoction teas commonly consumed in Nigeria using Atomic Absorption Spectrophotometry. Results revealed that Fe had the highest concentration with a mean value of 13.136 ± 0.195 µg/g, while As had the least mean concentration (0.043 ± 0.006 µg/g). Pollution index (PI) result indicated that the teas were contaminated with Cu (PI value > 1) while it was clear of contamination by the other investigated metals. Cluster analysis showed close inter-element relationships between the investigated metals, indicating similar chemical properties and/or genetic origin. Correlation matrix showed that positive and significant correlations existed between between Zn/Cr, Ni/Cr, Co/Cr, Fe/Cu, Mn/Cu, Ni/Zn, Co/Zn, Co/Ni and Mn/Fe, indicating chemical affinity. Estimated daily intake, target hazard quotient and cancer risk showed that there was no health risk associated with the consumption of the herbal concoction teas. Relative risk indicated that the highest concern is from the levels of Co in the teas. The study concluded that consumption of the teas may not pose risk to human health at the current levels of the metals, but should be consumed moderately to prevent bioaccumulation of the metals.