Distribution of Polychlorinated Biphenyls (PCBs) and Toxic Equivalency of Dioxin-Like PCB Congeners in Rural Soils of Beijing, China
Bibliographic record
Abstract
The soil quality in rural area may associate with the health of local residents and food safety. This study aimed to investigate the spatial and vertical distribution of PCBs in rural soils of Beijing, and the source identification of PCBs and toxic equivalency calculation of dioxin-like PCB congeners were conducted. The mean of total PCB concentrations in Beijing rural soils was 11.01 ng g-1. The congener profiles were predominated by lowly chlorinated congeners such as Di-CBs, Tri-CBs and Tetra-CBs. No significant difference of PCBs concentrations was observed between plain and mountain areas, and PCBs were slightly accumulated in the surface soils of Beijing rural area. Long-range transport of volatile PCB congeners was also an important source in addition to local sources of PCBs from electronic products. Toxic equivalency concentrations of dioxin-like PCB congeners met Canadian soil quality guidelines for agricultural soils, indicating a lower risk of PCBs to human health.
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".