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Record W1491291477

DETERMINATION OF DECHLORANE PLUS AND RELATED COMPOUNDS IN THE ENVIRONMENT

2011· dissertation· en· W1491291477 on OpenAlexfundaboutno aff
Ed Sverko

Bibliographic record

VenueMacSphere (McMaster University) · 2011
Typedissertation
Languageen
FieldEnvironmental Science
TopicChemistry and Chemical Engineering
Canadian institutionsnot available
FundersDalian Maritime UniversityHarbin Institute of TechnologyMcMaster University
KeywordsEnvironmental chemistryChemistryEnvironmental science
DOInot available

Abstract

fetched live from OpenAlex

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.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Other design · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.725
Threshold uncertainty score0.977

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0240.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.006
GPT teacher head0.163
Teacher spread0.157 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

Study designOther design
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations2
Published2011
Admission routes2
Has abstractyes

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