Exposure‐Based Toxicological Evaluation of Lead and Elemental Impurities in Encapsulated Green Tea Dietary Supplements Under a Regulatory Framework

ABSTRACT

The consumption of green tea ( Camellia sinensis (L.) Kuntze) in the form of encapsulated dietary supplements has increased substantially in recent years; however, data supporting toxicological risk assessment of inorganic contaminants in these products remain limited. Unlike traditional tea infusions, encapsulated supplements deliver concentrated plant material in fixed daily doses, requiring exposure‐based rather than concentration‐based toxicological evaluation. In this study, arsenic (As), cadmium (Cd), and lead (Pb) were quantified in 11 batches of commercially available encapsulated green tea supplements from six brands marketed in Southeast Brazil. Elemental analysis was performed using graphite furnace atomic absorption spectrometry (GF AAS), and measured concentrations (mg·kg ⁻¹ ) were converted into estimated daily intake (EDI, μg/day) based on the maximum labeled intake. Toxicological relevance was primarily assessed using permitted daily exposure (PDE) limits established in United States Pharmacopeia (USP) Chapter <2232>, with complementary interpretation based on estimated weekly intake (EWI) and provisional tolerable weekly intake (PTWI) reference values. Estimated daily exposures to arsenic, conservatively assumed as inorganic arsenic, and cadmium remained below their respective PDE values in all analyzed batches. In contrast, lead exposure exceeded the USP <2232> PDE of 5 μg/day in two batches, revealing batch dependent noncompliance under an exposure‐based regulatory framework. These findings demonstrate that dietary supplements may act as concentrated sources of elemental exposure and highlight the importance of dose‐normalized assessment for accurate risk characterization. The integration of PDE with complementary exposure metrics strengthens the evaluation of toxicological risk and supports more robust, exposure‐based regulatory approaches for the safety assessment of botanical dietary supplements.