Lead-glazed ceramics

Walton, M.S. (2009) PLS regression to determine lead isotope ratios of Roman lead glazed ceramics by laser ablation TOF-ICP-MS. In Isotopes in Vitreous Materials, edited by Degryse, P, Henderson, I, Hodgins, G. Leuven, Belgium Leuven University Press, pp. 141-157. 

Tunstall,S.,Amarasiriwardena,D.(2002) Characterization of lead and lead leaching properties of lead glazed ceramics from the Solis Valley, Mexico, using inductively coupled plasma-mass spectrometry (ICP-MS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). Microchemical Journal, 73, 335-347. 

Gersberg RM, Gaynor K, Tenczar D, et al. 1997. Quantitative modeling of lead exposure from glazed ceramic pottery in childhood lead poisoning cases. International Journal of Environmental Health Research 7(3) 193-202. 

Roberge RJ, Martin TG, Dean BS, et al. 1994. Ceramic lead glaze ingestions in nursing home residents with dementia. Am J Emerg Med 12 77-81. 

Roque J, Molera J, Sciau P, Pantos E, Vendrell-Saz M (2006) Copper and silver nanocrystals in lustre lead glazes development and optical properties. J European Ceramic Society 26 3813-3824. 

Schwedt, A Buxeda i Garrigos, J. Madrid Fernandez, M. In Study of Technological Differences in Tin Lead Glazes, paper presented at EMAC 05, Proceedings of the 8th European Meeting on Ancient Ceramics Lyon, 260>-29fl> Odober, 2005 Lyon. 

Trace amounts of lead have been reported previously in monochrome-glazed ceramics dating to the Parthian and Sasanian Periods (4, 5, 12). The presence of these trace amounts of lead have been attributed to differences in the sources of pottery, accidental inclusion, or the smooth appearance of the glaze... 

Figure 2. Plot of the relationship of copper to lead in the glazed ceramic sample. The ellipses represent 90% confidence intervals.

Monochrome black, pea-green and white, or white glazes mottled with black were produced using primarily alkaline-based glazes. Only one example of each of these types was also produced using low-lead, alkaline-based glazes. Ceramics in this group date from the Parthian, Sasanian and Islamic Periods. 

Later Islamic Post-Ninth century A.D. The first lead-glazed pottery, sgraffito is produced outside of southern Mesopotamia (INAA Group 3). Alkaline-based and low-lead, alkaline-based glazed pottery continues to be produced (INAA Group 1). INAA Group 2 ceramics continue to be produced. 

Because of the long-term and widespread use of lead, it is one of the most ubiquitous of the toxic metals. Exposure may be through air, water, or food sources. In the United States the major industrial uses, such as in fuel additives and lead pigments in paints, have been phased out, but other uses, such as in batteries, have not been reduced. Other sources of lead include lead from pipes and glazed ceramic food containers. 

Yellow lead(II) oxide, known as litharge, is widely used to glaze ceramic ware. Lead(IV) oxide does not exist in nature, but a substance with the formula PbOj.9 can be produced in the laboratory by oxidation of lead(II) compounds in basic solution. The nonstoichiometric nature of this compound is caused by defects in the crystal structure. The crystal has some vacancies in positions where there should be oxide ions. These imperfections in the crystal (called lattice defects) make lead(IV) oxide an electrical conductor, since the oxide ions jump from hole to hole. This makes possible the use of lead(IV) oxide as an electrode (the cathode) in the lead storage battery. 

In acetoxy systems acetic acid is produced during cure. This type of system is not ideal for use on alkaline surfaces. However, it has excellent adhesion to glass and glazed ceramics, making it ideal for use in all types of glazing and sanitary applications. Acetic system types should not be used on sensitive surfaces (e.g. concrete, zinc, lead, copper, brass, iron and some coated glasses). 

Lead raw glazes are often used for ceramic art ware, but seldom on an industrial scale owing to the danger of poisoning with lead compounds. If a lead glaze is to be used, it is more convenient to introduce PbO into the glaze in the form of a pre--melted frit. 

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