Assessment of the Potential Health Risks Associated with the Toxic and Essential Elements Content in Tea Samples...

Tea is a widely consumed beverage that may contain both essential and toxic metals, raising nutritional and health concerns. This study evaluated the transfer of selected essential and toxic metals from black tea leaves to their infusions and assessed the associated health risks and nutritional contributions.

Black tea leaves and their infusions from eight commercially available brands sold in Türkiye were analyzed. Toxic elements [arsenic (As), aluminium, cadmium (Cd), lead (Pb)] were quantified using inductively coupled plasma mass spectrometry, while essential elements [copper, iron (Fe), magnesium (Mg), zinc] were quantified using flame atomic absorption spectrometry. Health risks were evaluated using the Estimated Daily Intake, the Target Hazard Quotient (THQ), the Hazard Index (HI), and the Incremental Lifetime Cancer Risk (ILCR).

In dry tea leaves, aluminum was the predominant toxic element (12.6–25.3 mg/g), followed by Pb (21.0–39.0 μg/g); As and Cd were present at lower levels. Mg (523.0–1421.0 μg/g) and Fe (263.1–445.5 μg/g) were the most abundant essential elements. Metal concentrations in tea infusions were significantly lower than those in dry leaves (p < 0.05), indicating limited transfer during brewing. In infusions, aluminum (0.5–1.0 mg/g) and Mg (88.5–413.4 μg/g) were the dominant toxic and essential elements, respectively. All THQ values and the combined HI were below 1, indicating no significant non-carcinogenic risk. ILCR values for Pb were below 10^-6, whereas those for As ranged from 10^-6 to 10^-4, indicating a moderate carcinogenic risk for As.

The transfer of metals from tea leaves to infusions is limited, likely due to chelation and complexation during brewing. Under typical consumption conditions, black tea infusions were within established safety limits, with risk indices below thresholds of concern. While As warrants continued monitoring, essential elements contribute only a small fraction of the recommended daily intakes. The small sample size is a limitation.