Health risk assessment of heavy metals in black tea infusion by Monte Carlo simulation

Tea leaves and their infusion have been interested in the populations because of their therapeutic and relaxing effects. However, tea plant is prone to heavy metals' bioaccumulation. Regarding the high consumption of tea infusion, concentration of arsenic, cadmium, and lead in black tea infusion was determined by inductively coupled plasma mass spectrometry. Tea infusion was prepared by addition of 45 mL deionized water to 1 g tea leaves followed by heating at 90°C for 10 min. After analysis, carcinogenic and noncarcinogenic risks of heavy metals were investigated by Monte Carlo simulation in two age groups of children and adults younger and older than 15 years old, respectively. According to the results, Hazard Quotient (HQ) of three heavy metals in both children and adults was equal and lower than 0.01. Furthermore, incremental lifetime cancer risk (ILCR) of arsenic in Iranian black tea consumers (<1.5 × 10^-6) and lead in all consumers (about 2.55 × 10^-7) was within the acceptable range introduced by US EPA (≤10^-6). ILCR of arsenic in children and adults consuming foreign tea infusion was within the range of 10^-6-10^-4. Our further investigation revealed that the highest area (75%-85%) of cumulative frequency distribution for arsenic ILCR in foreign tea consumers was related to ILCR ≤10^-5 which is the acceptable range determined by the World Health Organization. Therefore, there was no serious concern about the intake of heavy metals by tea infusion in Iranian children and adults.