Insights into the Global Distribution of Polychlorinated Dibenzo-<i>p</i>-dioxins and Dibenzofurans
Bibliographic record
Abstract
Polychlorinated dibenzo- p -dioxins and dibenzofurans were measured in 63 pairs of tree bark and soil samples. Maps of lipid-adjusted concentrations in bark and fluxes to soil indicated that Vancouver Island, the Midwestern United States, Germany, and Hong Kong were areas of high PCDD/F deposition. Concentrations and fluxes in the regions north of the 60th parallel, particularly the Canadian Arctic, were low, indicating that PCDD/F do not move appreciably from warm to cold latitudes. Linear regressions of the PCDD/F concentrations in tree bark versus fluxes to soil showed that total concentrations in bark can be used to estimate total fluxes to soil in a particular region. Comparison of the homologue profiles for each pair of bark and soil samples indicated that the pairs fell into three categories: 1. bark and soil both resembled source profiles; 2. bark and soil both resembled sink profiles; and 3. bark resembled a source profile but the soil resembled a sink profile. This variation in homologue profiles may be due to the proximity of sampling locations to sources. We found that anthropogenic NO x emissions are highly correlated to PCDD/F soil fluxes, and we used this regression to estimate global PCDD/F fluxes to soil on the same spatial scale as the NO x data. Multiplying these fluxes by the corresponding land areas, we estimated that total PCDD/F deposition to the earth's land surface is about 2−15 t/yr.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.002 |
| Science and technology studies | 0.001 | 0.007 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 teacher head, 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".