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Author (up) Henderson, R.G.; Verougstraete, V.; Anderson, K.; Arbildua, J.J.; Brock, T.O.; Brouwers, T.; Cappellini, D.; Delbeke, K.; Herting, G.; Hixon, G.; Wallinder, I.O.; Rodriguez, P.H.; Van Assche, F.; Wilrich, P.; Oller, A.R.
Title Inter-laboratory validation of bioaccessibility testing for metals Type
Year 2014 Publication Regulatory Toxicology And Pharmacology Abbreviated Journal Regul. Toxicol. Pharmacol.
Volume 70 Issue 1 Pages 170-181
Keywords Metals; Alloys; UVCBs; Classification; Bioelution; Bioaccessibility; Read-across; Inter-laboratory validation
Abstract Bioelution assays are fast, simple alternatives to in vivo testing. In this study, the intra- and inter-laboratory variability in bioaccessibility data generated by bioelution tests were evaluated in synthetic fluids relevant to oral, inhalation, and dermal exposure. Using one defined protocol, five laboratories measured metal release from cobalt oxide, cobalt powder, copper concentrate, Inconel alloy, leaded brass alloy, and nickel sulfate hexahydrate. Standard deviations of repeatability (S-r) and reproducibility (S-R) were used to evaluate the intra- and inter-laboratory variability, respectively. Examination of the s(R):s(r) ratios demonstrated that, while gastric and lysosomal fluids had reasonably good reproducibility, other fluids did not show as good concordance between laboratories. Relative standard deviation (RSD) analysis showed more favorable reproducibility outcomes for some data sets; overall results varied more between- than within-laboratories. RSD analysis of s(r) showed good within-laboratory variability for all conditions except some metals in interstitial fluid. In general, these findings indicate that absolute bioaccessibility results in some biological fluids may vary between different laboratories. However, for most applications, measures of relative bioaccessibility are needed, diminishing the requirement for high inter-laboratory reproducibility in absolute metal releases. The inter-laboratory exercise suggests that the degrees of freedom within the protocol need to be addressed. (C) 2014 Elsevier Inc. All rights reserved.
Address [Henderson, Rayetta G.; Hixon, Greg] ToxStrategies Inc, Raleigh, NC 27615 USA, Email: rhenderson@toxstrategies.com;
Corporate Author Thesis
Publisher Academic Press Inc Elsevier Science Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0273-2300 ISBN Medium
Area Expedition Conference
Notes WOS:000342482200018 Approved
Call Number UAI @ eduardo.moreno @ Serial 412
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Author (up) Urrestarazu, P.; Villavicencio, G.; Opazo, M.; Arbildua, J.; Boreiko, C.; Delbeke, K.; Rodriguez, P.H.
Title Migration protocol to estimate metal exposure from mouthing copper and tin alloy objects Type
Year 2014 Publication Environmental Health Abbreviated Journal Environ. Health
Volume 13 Issue Pages 9 pp
Keywords Lead; Mouthing; Migration test; Alloys; Chronic exposure; Saliva
Abstract 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.
Address [Urrestarazu, Paola; Villavicencio, German; Opazo, Margaret; Arbildua, Jose; Rodriguez, Patricio H.] Univ Adolfo Ibanez, Ctr Ecotoxicol & Chem Met, Santiago 2700, Chile, Email: patricio.rodriguez@uai.cl
Corporate Author Thesis
Publisher Biomed Central Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-069x ISBN Medium
Area Expedition Conference
Notes WOS:000340967800001 Approved
Call Number UAI @ eduardo.moreno @ Serial 402
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