Review of 6PPD-quinone environmental occurrence, fate, and toxicity in stormwater
Bibliographic record
Abstract
The antioxidant N-(1,3-dimethylbutyl)-N?-phenyl-p-phenylenediamine (6PPD) is widely used to improve the durability of rubber. However, one of its transformation products, 6PPD-quinone (6PPD-Q), was recently found to be toxic. Herein, we aim to provide a comprehensive understanding of 6PPD-Q ecological and human-linked toxicity to facilitate the preparation of robust and specific environmental standards and policies. We reviewed 6PPD-Q environmental occurrence, fate, and toxicity originating from stormwater runoff and summarised its origin and environmental shaping conditions. Stormwater runoff was found to be the main driver in introducing 6PPD-Q into the environment. 6PPD-Q detection in roadside soils and other vehicle-related environments indicates that vehicle tyres are the major source of this compound; its presence in the soil can contaminate plants, thereby entering the food cycle. 6PPD-Q air concentrations were higher at roadside sites than at secluded building sites. Nevertheless, the mechanisms underlying 6PPD-Q toxicity and their relationship to various environmental factors, other contaminants, and removal technologies remain unknown. Addressing these gaps can help raise 6PPD-Q environmental risk awareness and facilitate development innovations to mitigate 6PPD-Q-linked risks.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".