Leaching and In Vivo Bioavailability of Antimony in PET Bottled Beverages

Antimony (Sb) may leach from polyethylene terephthalate (PET) materials into bottled water under improper storage conditions, particularly at high temperatures, leading to potential Sb chronic exposure and adverse health effects. However, Sb leaching may be promoted by various beverage constituents, which has received limited attention to date. In addition, few studies have considered Sb bioavailability in beverages and the influence of the beverage matrix on Sb bioavailability. In this study, PET-bottled beverages (n = 50) covering six categories (namely, carbonated, fruit juices, tea, sports, protein, and coffee beverages) were explored. Antimony leaching was assessed following the incubation of beverages at 60 °C for 7 days, which resulted in Sb concentrations 1.10-10.9 times greater than concentrations observed pre-incubation. Although regulatory standards vary internationally, a total of 21 beverages exceeded the Japanese Sb drinking water standard of 2 μg/L (up to 4.08 ± 0.11 μg/L) following incubation at 60 °C. pH significantly influenced Sb leaching (r = -0.38, p = 0.007) with beverages displaying lower pH (e.g., carbonated drinks) exhibiting higher Sb concentrations. An in vivo mouse model, using the liver as the biological endpoint, was adopted to assess Sb relative bioavailability (RBA) in bottled beverages. Sb RBA ranged from 1.97-58.7% with coffee beverages exhibiting the lowest Sb RBA (1.97-13.7%) and protein drinks the highest (41.1-58.7%). Linear regression revealed that Sb RBA in beverages was negatively influenced by Fe (r = -0.69, p = 0.02) and P (r = -0.73, p = 0.01) concentrations but positively correlated with tartaric acid (r = 0.59, p = 0.02). When an exposure assessment was undertaken using data generated in this study, carbonated and protein-rich beverages exhibited a higher exposure risk due to elevated Sb leaching and high Sb RBA compared to other beverage categories.