Comprehensive Evaluation of Potentially Toxic Elements in Tea: Bioavailability, Bio-accessibility, and Health Risk Analysis Using Multimodal Statistics.

Tea is the most consumed beverage worldwide and is renowned for numerous health benefits. However, potentially toxic elements (PTEs) in tea leaves are a global concern. This study evaluates the bioavailability of PTEs in tea soils, their transfer to leaves and infusions, analyzing 100 samples from four different tea-growing zones in North Bengal, India. In zone 1 (North Dinajpur) the average transfer rate of Cr, Ni, Cu, Zn, and Pb from leaves to infusion were 16.19%, 17.08%, 3.81%, 5.66%, and 5.34%, respectively. Pb content in zone 1 tea samples marginally exceeded the permissible limit of 10 mg/kg specified by the Prevention of Food Adulteration Act. The analysis revealed that PTE contamination in tea leaves followed a decreasing order of contamination: zone 1 > zone 2 > zone 3 > zone 4. Self-organizing map revealed an inverse relationship among pH, organic carbon content, and bioavailable forms of PTEs. Sobol sensitivity analysis identifies a strong influence of leaf infusion particularly on the gastric phase of humans and the Random Forest algorithm emerged as the best-performing model in the Taylor Diagram. The FIAM-based hazard quotient (HQ) was above 0.5 for Cr, Ni, and Pb indicating a potential risk for the consumers. However, carcinogenic risk assessed via the Severity Adjustment Margin of Exposure (SAMOE) model was negligible. This report could be useful for establishing tolerance limits for toxic elements to mitigate the health hazards associated with tea consumption.