Evaluation of heavy metal concentrations in black tea and infusions in Neyshabur city and estimating health risk to consumers

摘要

Heavy metal pollution is one of the environmental problems and one of the critical concerns of food hygiene. Consumption of tea as a pleasant drink and food habit is common among Iranians.The presence of these metals in tea can be an essential source of contamination in food.This study aimed to investigate the levels of lead, chromium, nickel, cadmium, aluminium, and arsenic in samples of dry black tea and Infusionsin the market of Neyshabur in 2019.Samples were digested with nitric acid and perchloric acid, and the concentration of the desired metals was read by the spectrometric method.All experiments were performed in 3 replications.Then, the Provisional Tolerable Daily index (PTDI) and Hazard Quotient (HQ) levels of heavy metal intakes were calculated to estimate the health hazard for consumers.The Mean concentrations of Pb, Cr, Ni, As,Al, and Cd in the tea leavesand Infusions were 1.96, 3.05, 3.68, 0.048, 2.195, 0.03 mg/kg and 0.07, 0.17, 0.88, 0.03, 0.53, 0.003 mg/kg, respectively.The results also showed that the target hazard quotient (THQ) for Cr and Alis more than one. In the samples of dry tea and their Infusions, concentrations ofCrand Alwere exceeded from Iran's Ministry of Health and WHO guidelines. The two elements of Ni and Pb are more than the Iranian National Standards Organisation'sinstructions.HQ values for chromium and aluminium obtainedhigher than one, which indicatedadverse effectson tea consumers' health. Therefore, continuous monitoringis essential to determine the toxic metals'concentrationsin tea samples.