Bibliographic record
Abstract
Abstract Polyhalogenated aromatic hydrocarbons (PHAHs) comprise a large group of semi-volatile chemicals that are stable at high temperatures, highly soluble in lipids, and resistant to biodegradation. Unfortunately, these properties enable PHAHs to disperse and persist in the environment, to bioaccumulate in terrestrial and aquatic food chains, and to cause unforeseen adverse health effects among wildlife and humans. All of us probably have detectable PHAHs in our bodies, the concentrations of PCBs generally being much higher than those of other PHAHs. Chlorinated, brominated, and mixed halogenated PHAHs have similar structures and toxicity but widely variable potencies; major subgroups include biphenyls, dibenzo-p-dioxins, and dibenzofurans (Table 6–1). Monsanto, the sole manufacturer of PCBs in the United States, produced about 700,000 tons during the period 1929–1979, annual output peaking in 1970 at 43,000 tons. Given their high heat capacity and stability, PCBs were ideal for uses in heat-resistant solvents, sealants, and lubricants, and as dielectric fluids in electrical transformers, fluorescent light ballasts, and other electrical equipment. The most intensely studied PHAH is 2,3,7,8tetrachloro-p-dibenzodioxin (TCDD), one of the most potent known toxicants (Schiestl et al., 1997).
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 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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.004 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.045 | 0.033 |
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".