High level leaching of heavy metals from colorful ceramic foodwares: a potential risk to human
Environmental Science and Pollution Research Vol. 24, No. 20, 17116-17126 p.
Abstract Ceramic foodwares are among the products used by people on daily basis without being cautious of exposures to heavy metals through possible leaching from the glaze ce- ramics. This study investigated the levels of heavy metals foundinsomecommonlyusedceramicfoodwaresin Nigeria with the aim of determining levels of human expo- sures through the use of the ceramics. To achieve this, acid digestion was carried out for the total metal concentrations and leaching tests were done using 4% acetic acid as a leaching agent. Metal concentrations were quantified using flame atomic absorption spectrometry (FAAS) and particle-induced X-ray emission spectrometry (PIXES) analysis. All the ceram- ic foodwares studied were found to contain varied amounts of heavy metals in their glazes, with concentrations in the range of 26.45–2071.46, 5.20–547.00, 1.24–2681.02, 2590.00– 8848.40, 6.42–654.66, 112.69–649.95, 63.38–2518.51, and 3786.51–8249.44 μgg −1 for Pb, Cd, Zn, As, Cu, Cr, Mn, and Fe, respectively. Concentrations of the metals leached from the ceramics were in the range of 0.11–0.97, 0.01– 0.28, 0.00–4.19, 1.93–15.00, 0.01–0.41, 0.09–0.60, 0.01– 2.14, and 0.01–11.53 mgL −1 for Pb, Cd, Zn, As, Cu, Cr, Mn, and Fe, respectively. Comparing the ratio of the metals leached from the ceramic wares with those of the metal oxides in the ceramics, it was noticeable that not all the metals de- tected in the ceramic samples were domiciled in the glaze but in the clay materials used for the ceramics.