Concentrations, sources and risk characterisation of polycyclic aromatic hydrocarbons (PAHs) in green, herbal and black tea products in Nigeria

This study describes the analysis of 16 + 1 US-EPA Priority PAHs (polycyclic aromatic hydrocarbons) occurrence in twenty-three (23) imported and locally manufactured samples of green, black and herbal tea commercially marketed and widely consumed in Nigeria. A gas chromatograph (GC) coupled with an auto-sampler in tandem with a flame ionisation detector (FID) was used for the analysis. The percentage recoveries of each individual PAH varied between 90.24 and 108.92%. The degree of contamination expressed as sum of sixteen priority PAHs (∑16PAHs) ranged between 1.63 ± 0.33-73.53 ± 6.07 μg/kg, 4.71 ± 0.23-79.61 ± 7.02 μg/kg, and 12.52 ± 0.15-26.89 ± 0.68 μg/kg, for green, herbal and black tea samples, respectively. Benzo(a)pyrene played a significant role in the carcinogenicity and mutagenicity potentials of the samples. The lifetime cancer incident risk assessments indicate higher cancer risk levels in herbal and black teas. Generally, children have higher lifetime probability of cancer risk than adults.