DETERMINATION OF DECHLORANE PLUS AND RELATED COMPOUNDS IN THE ENVIRONMENT
Notice bibliographique
Résumé
Dechlorane Plus (DP) is a chlorinated flame retardant used in wire coatings, furniture and hard plastic connectors in computer monitors. It is manufactured in high volumes with production facilities located in the United States and China bringing into question whether the flame retardant existed in the environment. DP was detected in Lake Ontario sediments at concentrations 60-fold greater than in Lake Erie sediments; the maximum values were 586 ng g<sup>-1</sup> and 8.6 ng g<sup>-1</sup>, respectively. These data suggest there is DP source into the Niagara River, which contributed to Lake Ontario’s DP burden. Analyses of Lake Ontario sediment core slices showed that recent concentrations were two orders of magnitude less than the core’s maximum concentration of 920 ng g<sup>-1</sup> (1976-1980). New chemicals related to DP were also found in this core which DP’s profile, suggesting these compounds maybe impurities or side products in the manufacture of DP. The concentrations of one of the mono Diels-Alder adducts, 1,3-DPMA, was found in Lake Ontario lake trout to be two orders of magnitude greater than that of DP, suggesting the monoadduct is more bioaccumulative than DP. Analysis of a Lake Ontario food web illustrated that 1,3-DPMA was being diluted up the food chain, much like DP, while a second monoadduct, 1,5-DPMA was only detected in lower trophic species. <em>In vitro</em> lake trout liver microsomal exposures to the individual DPMA isomers showed that the depletion rate constant for 1,3- and 1,5-DPMA were 0.34 and 0.84 h<sup>-1</sup>, respectively, with corresponding t<sub>1/2</sub>’s of 2.02 ± 0.50 and 0.83 ± 0.18 h, respectively. The shorter 1,5-DPMA half-life was ascribed to the unsterically hindered double bond which allowed for greater enzyme attack. Dechlorination of DP was observed during the analysis of sediment extracts and was attributed as being an artefact of dirty injector liners; care needs to be taken to insure this dechlorination does not occur during analysis of environmental samples. This was important as dechlorinated DP products were observed in Lake Ontario sediment and core extracts. DP was shown to be a worldwide airborne contaminant from analysis of passive samplers over a period of one year. The maximum concentration was detected in Delhi, India (226 pg m<sup>-3</sup>). Middle Eastern and Indo-Asian regions exhibited the greatest concentrations in the world providing likely the result of other DP manufactures and/or that the practice of open pit burning of wires and cables was adding to the regions air burden.
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 | 0,000 | 0,000 |
| 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) | 0,024 | 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 ».