Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects

Environmental Health

Methodology

Margaret Opazo¹  Patricio H Rodriguez¹  Germán Villavicencio¹  Paola Urrestarazu¹  José Arbildua¹  Katrien Delbeke²  Craig Boreiko³ 

[1] Center of Ecotoxicology and Chemistry of Metals, Universidad Adolfo Ibañez, 2700, Diagonal Las Torres, Peñalolen, Santiago, Chile;European copper Institute, Avenue de Tervueren 168 b10, B-1150, Brussels, Belgium;International Lead Zinc Research Organization, 1822 NC Highway 54 East, Suite 120, 27713, Durham, NC, UK;

关键词: Lead;    Mouthing;    Migration test;    Alloys;    Chronic exposure;    Saliva;   

DOI  :  10.1186/1476-069X-13-66

 received in 2014-03-31, accepted in 2014-08-07,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundLow blood lead levels previously thought to pose no health risks may have an adverse impact on the cognitive development of children. This concern has given rise to new regulatory restrictions upon lead metal containing products intended for child use. However few reliable experimental testing methods to estimate exposure levels from these materials are available.MethodsThe present work describes a migration test using a mimetic saliva fluid to estimate the chronic exposure of children to metals such as lead while mouthing metallic objects. The surrogate saliva medium was composed of: 150 mM NaCl, 0.16% porcine Mucin and 5 mM buffer MOPS, adjusted to pH 7.2. Alloys samples, in the form of polished metallic disc of known surface area, were subjected to an eight hours test.ResultsTwo whitemetal alloys Sn/Pb/Sb/Cu and three brass alloys Cu/Zn/Pb were tested using the saliva migration protocol. In the case of the whitemetal alloys, first order release kinetics resulting in the release of 0.03 and 0.51 μg lead/cm2 after 8 hours of tests were observed, for lead contents of 0.05-0.07% and 5.5%, respectively. Brasses exhibited linear incremental release rates of 0.043, 0.175 and 0.243 μg lead/cm2h for lead contents of 0.1-0.2%, 1.7-2.2% and 3.1-3.5%, respectively. The linear regression analysis of lead release rates relative to Pb content in brasses yielded a slope of 0.08 μg lead/cm2h%Pb (r2 = 0.92). Lead release rates were used to estimate the mean daily mouthing exposure of a child to lead, according to age-specific estimates of mouthing time behavior. Calculated daily intakes were used as oral inputs for the IEUBK toxicokinetic model, predicting only marginal changes in blood lead levels (0.2 μg lead/dL or less) for children aged 0.5 to 1 years old exposed to either class of alloy.ConclusionsThe results of this study as a whole support the use of migration data of metal ions, rather than total metal content, to estimate health risk from exposure to metals and metal alloys substances in children.

【 授权许可】

Unknown   
© Urrestarazu et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.