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

BACKGROUND: Low 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 t...

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Autores principales: Urrestarazu, Paola, Villavicencio, Germán, Opazo, Margaret, Arbildua, José, Boreiko, Craig, Delbeke, Katrien, Rodriguez, Patricio H
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4237810/
https://www.ncbi.nlm.nih.gov/pubmed/25113236
http://dx.doi.org/10.1186/1476-069X-13-66
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author Urrestarazu, Paola
Villavicencio, Germán
Opazo, Margaret
Arbildua, José
Boreiko, Craig
Delbeke, Katrien
Rodriguez, Patricio H
author_facet Urrestarazu, Paola
Villavicencio, Germán
Opazo, Margaret
Arbildua, José
Boreiko, Craig
Delbeke, Katrien
Rodriguez, Patricio H
author_sort Urrestarazu, Paola
collection PubMed
description BACKGROUND: Low 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. METHODS: The 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. RESULTS: Two 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/cm(2) 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/cm(2)h 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/cm(2)h%Pb (r(2) = 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. CONCLUSIONS: The 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.
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spelling pubmed-42378102014-11-21 Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects Urrestarazu, Paola Villavicencio, Germán Opazo, Margaret Arbildua, José Boreiko, Craig Delbeke, Katrien Rodriguez, Patricio H Environ Health Methodology BACKGROUND: Low 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. METHODS: The 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. RESULTS: Two 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/cm(2) 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/cm(2)h 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/cm(2)h%Pb (r(2) = 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. CONCLUSIONS: The 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. BioMed Central 2014-08-11 /pmc/articles/PMC4237810/ /pubmed/25113236 http://dx.doi.org/10.1186/1476-069X-13-66 Text en Copyright © 2014 Urrestarazu et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/4.0 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.
spellingShingle Methodology
Urrestarazu, Paola
Villavicencio, Germán
Opazo, Margaret
Arbildua, José
Boreiko, Craig
Delbeke, Katrien
Rodriguez, Patricio H
Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
title Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
title_full Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
title_fullStr Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
title_full_unstemmed Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
title_short Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
title_sort migration protocol to estimate metal exposure from mouthing copper and tin alloy objects
topic Methodology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4237810/
https://www.ncbi.nlm.nih.gov/pubmed/25113236
http://dx.doi.org/10.1186/1476-069X-13-66
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