Heavy Metals Level, Health Risk Assessment Associated with Contamination of Black Tea; A Case Study from Khyber Pakhtunkhwa (KPK), Pakistan.

In the present study, 15 different commercial tea brands sold in Khyber Pakhtunkhwa were collected from the markets. The samples were analyzed for the concentrations of ten selected heavy metals. The metal concentration showed a random distribution in all samples. The mean concentration of Cd, Cu, Mn, Pb, Zn, and Fe was found in the range of 0.029-0.094 mg kg, 7.11-12.30 mg kg, 20.73-24.17 mg kg, 0.159-0.824 mg kg, 1.136-2.938 mg kg, and 0.670-118.30 mg kg respectively. Co, Cr, Ni, and Sb were found below the detection limit of the instrument. Cu and Mn were found to be the abundant metals with a high concentration in the collected samples. The estimated daily intake (EDI), target hazard quotients (THQs), and hazard index (HI) were used for the assessment of health risks associated with the intake of metals. The metal transfer rates to tea infusion were reported from previous studies. Except for Cu, the EDI values of all the elements were found to be lower than the RfD values. The corresponding HI values of metals, in the different tea brands, were found to be below 1 suggesting that the consumption of mature tea infusions in the studied area could cause no carcinogenic risk. The principle cluster analysis (PCA) was used to reduce the number of variables to a new set which extracted three factors. For the assessment of health risks associated with dietary metal exposure, constant determination of heavy metals in all food is necessary. The present study provides valuable information to the general public about the consumption of tea infusions.