Plumbism occurred in a patient after he had used a lead-glazed drinking vessel. Apparently, sufficient lead was leached from the mug's glazed inner surface by a soft drink with a pH of 2.7 to result in clinical saturnism after two years of habitual exposure. Laboratory and experimental studies confirmed the available quantity of lead in the source. Similar cases of lead poisoning resulting from the use of acidic food or drink with lead-glazed utensils have occurred in the past.
Harris RW, Elsea WR. Ceramic Glaze as a Source of Lead Poisoning. JAMA. 1967;202(6):544-546. doi:10.1001/jama.1967.03130190150031