Leachable lead and cadmium in microwave-heated ceramic cups: possible health hazard to human

In this study, we assessed the leachability as well as health risk associated with the consumption from glazed, colourful, ceramic cups, containing lead and cadmium. Both metals leached into the 2.5-min microwave-heated (convection mode, at 140 degrees C) double-distilled water in concentrations above 0.5 mg/L, the permissible limits of leachable Pb and Cd in ceramic mugs set by United States Food and Drug Administration (US FDA). On an average, significantly higher Pb leached in new cups, 7.69 +/- 0.56 mg/L, compared to that in old cups, 3.15 +/- 0.15mg/L. Cd leached similarly in both old (1.97 +/- 0.14 mg/L) and new cups (1.57 +/- 0.005 mg/L). The chronic daily intake of Pb by children and adults, respectively, consuming from new cups were 1.3-5x and 1.28-6x more than that from old cups. In both the cases, intake values far exceeded WHO reference dose of 0.0006 mg Pb/kg bw/day in children (<11years) and 0.0013mg Pb/kg bw/day in adults. Such levels of Pb consumption in children might be predicted to be associated with decrement in IQ by at least 1 point and adverse effects in adults, especially, women of childbearing age. The daily intake of Cd from these cups ranged from 0.002-0.049 mg/kg bw/day, which was also above permissible limit. Consequently, high hazard quotient and hazard index (both more than 1) were observed for these metals, which might impart individual as well as cumulative effects on the health. Thus, apart from other dietary as well as inhalation sources of contaminants (which were not studied here), regular consumption of beverages alone in glazed, ceramic cups increased chances of Pb- and Cd-related health risks to humans.