| Titre | Choosing a robust method to estimate the bioaccessibility of arsenic from contaminated substrates |
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| Auteur | Meunier, L; Lord-Hoyle, M; Walker, S R; Koch, I; Wragg, J; Jamieson, H E; Parsons, M B ; Reimer, K J |
| Source | 5th SETAC (Society of Environmental Toxicology and Chemistry) World Congress, 2008 abstracts volume; 2008, 1p. |
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| Année | 2008 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20080141 |
| Réunion | 5th SETAC (Society of Environmental Toxicology and Chemistry) World Congress; Sydney; AU; août 3-7, 2008 |
| Document | livre |
| Lang. | anglais |
| Media | CD-ROM |
| Sujets | sols; études pédologiques; géochimie du sol; arsenic; résidus; analyses des résidus; pédologie; minéralogie; géologie de l'environnement |
| Programme | Environnement et santé |
| Résumé | (disponible en anglais seulement)
Though bioaccessibility (BA) of arsenic from soil is becoming more commonly used in risk assessment, concerns remain on the reliability of BA measurements. For
a series of reference materials, soils and tailings, three published BA tests (PBET, IVG and SBRC) were performed to determine the reliability of replicate measurements. BA test results were compared under a variety of test parameters, and for
different substrate characteristics (e.g. liquid to solid ratio, mineralogy, arsenic to iron ratio, etc.). The arsenic BA results varied from 0.5 to 60%. The PBET method returned the highest repeatability and reproducibility, and is also relatively
insensitive to varying liquid to solid ratios. The IVG test results ranged in between those of the PBET and SBRC tests. The BA results from the SBRC method showed the greatest variations between replicates as well as between the gastric and
intestinal phases. The SBRC results are sensitive to the concentration of glycine in the buffer system and the amount of iron in the samples. Glycine may interact with dissolved iron and influence the concentration of arsenic in solution.
Further
results indicate that, in the case of tailings, the higher percent arsenic BA is associated with the presence of calcium iron arsenates, whereas samples composed predominantly of arsenopyrite and scorodite returned the lowest percent BA. Higher
arsenic concentrations are not necessarily associated with higher percent bioaccessibility. To fully characterize the risk of arsenic exposure, site specific contaminated substrate composition, arsenic concentration, species (mineralogy) and
bioaccessibility must be taken into consideration. Of the three methods tested, PBET appears to offer the most robust estimate of arsenic bioaccessibility. |
| GEOSCAN ID | 225258 |
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