Determination of metal ion content of beverages and estimation of target hazard quotients: a comparative study

BACKGROUND Considerable research has been directed towards the roles of metal ions in nutrition with metal ion toxicity attracting particular attention. The aim of this study is to measure the levels of metal ions found in selected beverages (red wine, stout and apple juice) and to determine their potential detrimental effects via calculation of the Target Hazard Quotients (THQ) for 250 mL daily consumption. RESULTS The levels (mean +/- SEM) and diversity of metals determined by ICP-MS were highest for red wine samples (30 metals totalling 5620.54 +/- 123.86 ppb) followed by apple juice (15 metals totalling 1339.87 +/- 10.84 ppb) and stout (14 metals totalling 464.85 +/- 46.74 ppb). The combined THQ values were determined based upon levels of V, Cr, Mn, Ni, Cu, Zn and Pb which gave red wine samples the highest value (5100.96 +/- 118.93 ppb) followed by apple juice (666.44 +/- 7.67 ppb) and stout (328.41 +/- 42.36 ppb). The THQ values were as follows: apple juice (male 3.11, female 3.87), stout (male 1.84, female 2.19), red wine (male 126.52, female 157.22) and ultra-filtered red wine (male 110.48, female 137.29). CONCLUSION This study reports relatively high levels of metal ions in red wine, which give a very high THQ value suggesting potential hazardous exposure over a lifetime for those who consume at least 250 mL daily. In addition to the known hazardous metals (e.g. Pb), many metals (e.g. Rb) have not had their biological effects systematically investigated and hence the impact of sustained ingestion is not known.