Dioxin Toxic Equivalent Concentrations in Maternal Blood Samples From Mexico
Bibliographic record
Abstract
ISEE-571 Objective: The North American Commission for Environmental Cooperation is conducting a study to determine the blood concentrations of POPs and toxic metals in primipara women in Mexico, Canada, and the United States. Here, we describe and compare the blood serum concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) and their total dioxin toxic equivalence (TEQ) in the Mexican samples. Materials and Methods: Blood was collected from 25 pregnant (third trimester and primipara) women (aged 16–30 yr) from 10 sites in Mexico; the sites were chosen from 5 background sites and 5 sites that were designated as hotspots based on potential contamination with 1 or more of the environmental chemicals of interest. Blood was collected from each of these mothers. However, because of the volume of serum needed for the dioxin measurements, 2 serum pools of 12.5 mL each per site were prepared. The individual congener PCDDs, PCDFs, and the dioxin-like PCBs were determined by gas chromatography/mass spectrometry and the results were adjusted for serum lipids. Results: The total mean TEQ from the 5 hotspots ranged from 5.34 ng/g to 18.89 ng/g lipids; however, if next highest sample had a concentration of 8.90 ng/g lipids. The TEQ for the 5 background samples ranged from 5.53 ng/g to 7.99 ng/g lipids. The hot spot concentrations of the other chemicals were similar to those from the other sites with the exception of slightly higher mono-ortho chlorinated PCBs. Conclusions: Similar to other POPs the environmental concentrations of dioxins and dioxin-like chemicals have generally been decreasing in the industrialized world. As part of the Stockholm Treaty, countries are to evaluate both the environment and their people in monitoring programs. These data will serve as a basis for such an evaluation. Dioxin concentration comparisons with the study populations in Canada and the United States will be described.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".