“A Pilot Study to Assess Lead Exposure from Routine Consumption of Coffee and Tea from Ceramic Mugs: Comparison to California Safe Harbor Levels”, 2017-02-06 (; similar):
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 2 different time points brewed in 5 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.
Results: The results of this pilot study suggest that lead in ceramic mugs can leach into coffee and tea. The measured lead concentrations ranged 0.2–8.6 μg/L in coffee, and from <0.2 to 1.6 μg/L in tea. No statistically-significant 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 5 mugs tested. Blood lead levels did not increase above regulatory or guidance values.
Conclusion: 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.
…Method: The 5 mugs chosen for this study were selected because they were found to contain lead in a screening-level assessment. Specifically, 24 mugs from the authors’ office were tested using an Olympus Innov-X Delta handheld X-Ray fluorescent (XRF) analyzer. Each mug was measured once with the XRF gun at its highest sensitivity setting, which required the tester to hold the analyzer over the mug for 45s. The 3 mugs with the highest resulting lead concentrations (1,223 to 7,034 mg/kg) were selected for the present study. These mugs each had decorative elements and will be referred to by their predominant colors: Green Decorative, Yellow Decorative, and Red Decorative. In addition, 2 representative mugs were selected from the batch of office mugs baring the authors’ company’s logo. These will be referred to as Black Logo1 and Black Logo2. All 5 mugs selected were in active use in the authors’ San Francisco, California, office environment, and were typically washed daily in an automatic dish washer. 4 of the 5 mugs were purchased in the U.S., and one was purchased in Europe (Red Decorative). The mugs all appeared to be in good condition, with no obvious signs of damage or wear.