Trace elements in imported black tea products in Iran: quantification and probabilistic health risk assessment

ABSTRACT

Tea is a highly consumed beverage around the world, and many studies have indicated its health benefits. However, tea products may contain heavy metals that may cause negative health effects due to their toxicity. This study aimed to quantify the levels of copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) in six different imported black tea brands marketed in Mashhad city, Iran. Twenty samples from each six black tea brands were obtained from the markets of Mashhad city, Iran, in 2012. Overall, the content of Cu, Zn, Pb and Cd ranged 6.81–35.21 mg/kg (mean = 15.87 mg/kg), 14.61–164.84 mg/kg (mean = 47.68 mg/kg), 0.038–1.62 mg/kg (mean = 0.72 mg/kg) and 0.006–0.19 (mean = 0.05 mg/kg), respectively. The mean concentration of Zn in brands C, E and F, the mean concentration of Pb in brand B and the mean concentration of Cd in brand E exceeded the Iranian and WHO standard levels. Additionally, the estimation of hazard index (HI) showed that there is no potential adverse health effect due to the consumption of the studied tea samples (HI < 1). In terms of HI, the brands were ordered as B > D > F > E > A > C. However, estimation of excess lifetime cancer risk (ELCR) for Pb showed that there is a significant lifetime cancer risk as a result of consuming the black tea products. but the estimation of ELCR for Cd showed no potential health risks.

KEYWORDS:

• Black tea
• heavy metals
• health risk assessment
• dietary exposure
• Camellia sinensis
• food safety

Disclosure statement

No potential conflict of interest was reported by the author(s).

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Funding

The present work was approved under the ethical code of IR.BUMS.REC.1400.142 by the Birjand University of Medical Sciences ethics committee.