Comparison of Glycine and Simulated Mammalian Digestion for Estimating Bioaccessible Cu, Ni, Pb, and Zn in Soils Receiving Smelter Emissions
Notice bibliographique
Résumé
MS1-02 Abstract: Risk assessment for contaminated sites frequently identifies ingestion of soil as the largest contributor to exposure of people, in particular children, in part because the default value for transfer of metals from ingested material to the bloodstream is 100%. Values less than this default can be used in a site-specific risk assessment; currently, the determination of an alternate value is achieved using in vivo studies, the cost of which are high. Alternates to in vivo studies are in vitro extractions, which purport to identify the amount of metal in the ingested material that is solubilized by gut passage and is thus available for intestinal transfer. These in vitro extractions are numerous, vary considerably in complexity, and are infrequently validated against in vivo studies of the same matrices. The objective of this work was to estimate the bioaccessible amounts of Cu, Ni, Pb, and Zn in 4 soils, 2 of which had elevated metals from smelter emissions and 2 of which were from similar sites but outside the footprint of smelter emissions. These metals were extracted from the soils either by the SBRC method (glycine at pH 2) or by simulated mammalian digestion (chyme), which included saliva, gastric, and intestinal phases. Total metals in these 4 soils were extracted by digestion with concentrated nitric acid as a comparison. Bioaccessible metals were considered to be that fraction of the total metal as determined by nitric acid digestion, which was solubilized by either the glycine or the simulated mammalian digestion. The amounts of these 4 metals that were solubilized by chyme were smaller than those resulting from nitric acid; the amounts of metals solubilized in chyme were very much smaller than the amounts solubilized by glycine. Part of this is likely due to the effect of pH: the final pH of the chyme (after the intestinal phase) is close to neutral, higher than the final pH of the glycine and nitric acid extractions. Efforts to simulate the selectivity of the intestinal barrier for the digested metals by intestinal epithelial (Caco-2) cells were not initially successful. The exposure of the cell monolayer to the chyme caused the layer to detach and the cells to lyse; efforts toward success with this system are continuing.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».