A pilot study to assess lead exposure from routine consumption of coffee and tea from ceramic mugs: Comparison to california safe harbor levels

Abstract

Background: Lead (Pb) is a pervasive metal that can be found in, and potentially leached from, ceramics, particularly into acidic foods and beverages. The purpose of this study was to investigate potential lead exposure from coffee and tea consumption, given that both are acidic and routinely consumed from ceramic mugs. We measured the concentration of lead in coffee and tea at two different time points brewed in five readily available mugs known to contain lead. Results were compared to EPA’s action level for drinking water and FDA’s allowable level for bottled water. The measured concentrations, along with consumption patterns, were also used to calculate potential daily lead doses, which were compared to California’s Safe Harbor Levels under Proposition 65. Additionally, we estimated changes in adult and fetal blood lead levels using EPA’s Adult Lead Methodology model. Findings: The results of this pilot study suggest that lead in ceramic mugs can leach into coffee and tea. The measured lead concentrations ranged from 0.2 to 8.6 μg/L in coffee, and from <0.2 to 1.6 μg/L in tea. No statistical differences were found between the measured concentrations in coffee, tea, or water within each cup, or in the measured concentrations between retention times within each cup. However, a statistically significant difference was observed in the lead concentrations measured between cups, indicating that the lead concentrations were dependent on the cup used, rather than on the beverage or retention time. The estimated daily dose of lead exceeded the California Maximum Allowable Dose Level of 0.5 μg per day for one of the five mugs tested. Blood lead levels did not increase above regulatory or guidance values. Conclusions: This preliminary investigation provides data on potential lead exposures from daily beverage consumption among typical consumers, relevant to a substantial portion of the population, with particular implications for pregnant women.