The Toxicological Safety Assessment of Heavy Metal Impurities (As, Pb, and Cd) in Mint Tea Infusions (Mentha piperita L.) Available in Polish Markets

Abstract

Mint tea (Mentha piperita L.) is one of the most widely consumed single infusion herbal teas (infusion) around the world; however, impurities and pollutants can pose a potential health risk to human health during tea drinking. The idea of this study was the comprehensive toxicological risk assessment (TRA) of three heavy metals (As, Pb, and Cd) in mint tea infusions (Mentha piperita L.; n = 17) available in Polish markets. We applied an inductively coupled plasma mass spectrometry (ICP-MS)-based methodology for the determination of the chosen heavy metals and designed a specific TRA approach. The first step in our TRA was the determination of the elements investigated (heavy metal impurity profile, µg/L of infusion). The second step was the estimation of the weekly intake (µg/L of infusion/week) based on the weekly consumption of tea. The third step was the estimation of the weekly intake per body weight (µg/L of infusion/week/bw) based on the weekly consumption of tea per adult person compared to the Provisional Tolerable Weekly Intake (PTWI) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The level of investigated heavy metals occurs in all of the investigated mint tea infusions but at a relatively low level. The heavy metal profile indicated presence of As (0.36-1.254 µg/L), Pb (0.47-1.24 µg/L), and Cd (0.17-0.40 µg/L) in all the samples investigated. The basic analysis of the general content shows that As levels (mean = 0.70 µg/L) were very similar to the Pb levels (mean = 0.72 µg/L). The Cd content (mean = 0.21 µg/L) was approximately 3.5 times lower than the As and Pb levels. TRA provides satisfactory results for regulatory purposes. TRA for the elements investigated in the analyzed products indicated that there was no health hazard to consumers for weekly exposure. The results indicated that the levels of investigated elements in daily doses should not represent any health hazard to the consumer after drinking mini tea infusions from products available in Polish markets. This well-designed TRA methodology was useful and important for regulatory toxicology purposes.

Keywords: Elemental profile; ICP-MS; Mint tea; Tea infusions; Toxicological risk assessment (TRA).