ارزیابی میزان غلظت فلزات سنگین در انواع چای سیاه و دم نوش مصرفی شمال ایران و برآورد خطر سلامت در مصرف کنندگان

Background and purpose: Heavy metals in tea causes harmful effects on the health of consumers. The aim of this study was to determine the concentrations of arsenic, lead, cadmium, chromium, cobalt and nickel in black tea and their infusions, and evaluation of their health hazards in Rasht, Iran. Materials and methods: A cross-sectional study was carried out in 54 samples of nine brands of black tea and their infusions including six Iranian and three foreign products that were selected randomly in 2014. After sample preparation, the concentration of heavy metals were determined by inductively coupled plasma atomic emission spectrometer (ICP-AES). Results: The range of concentrations of arsenic, lead, cadmium, chromium, cobalt, and nickel in black tea were 0.03-0.1, 0.5-3.5, 0.07-0.6, 0.9-3.9, 1.8-6.7, and 1.7 to 8.9 mg per kg and in their infusions were 0.01-0.03, 0.1-0.4, 0.04-0.2, 0.4-0.8, 0.2-1.2, and 0.6-2.1 mg per kg, respectively. The concentrations of arsenic and cadmium (22%) and lead (11%) were reported to be below the detection limit in black tea samples. Conclusion: Despite the high concentration of heavy metals in some samples of tea and their infusions, the estimated values of PTWI and THQ cause no consumer health risks according to the guidelines suggested by WHO and FAO. Nevertheless, continuous monitoring of heavy metals contamination in black tea and their infusions is highly necessary.