Risk assessment of lead, copper, manganese, zinc, cadmium, and iron in black tea products sold in Malaysia

Tea is the most popular beverage in the world that contains several essential nutrients which are beneficial to human health. In Malaysia, most consumers preferred black tea over other varieties of tea. However, several research carried out worldwide discovered the presence of heavy metals in black tea. Even at low concentrations, the presence of heavy metals in black tea raises concerns considering that they have a direct impact on human health. Therefore, this study aimed to evaluate the potential health risks associated with the heavy metals found in several commercial black tea brands in Malaysia. A total of 50 different commercial black tea brands were collected from the market, and the samples were analyzed for the concentration of 6 selected heavy metals using atomic absorption spectrophotometer (AAS). The results of AAS analysis showed that the level of Fe was 40.73-2.33 mg/kg, Zn was 12.48-5.15 mg/kg, Cu was 13.953.59 mg/kg, Mn was 22.85-3.27 mg/kg, Pb was 13.93-0.34 mg/kg, and Cd was 1.2-0.08 mg/kg. It was found that all metals had exceeded the permitted level of the Malaysian Food Act and Regulations and WHO/FAO except for Zn and Fe. This data was used in the calculation of Target Hazard Quotient (THQ) and Lifetime Cancer Risk (LCR) by using the formulas by USEPA 2011. From the calculations, it was found that several metals had THQ of more than 1 and Pb and Cd had LCR values of more than 10⁻⁶ . This indicates that the products can pose health and cancer risks to the majority of the population. As the black tea products sampled in this study can put the public’s health at risk, prompt action is necessary where product recall is done for those that violated the heavy metal content limit. It is recommended that risk assessment and monitoring be done in black tea plant farms as well as during the tea productions production process to ensure the teas are safe for human consumption.