Short-Term Effects of Ozone and PM<sub>2.5</sub> on Mortality in 12 Canadian Cities
Bibliographic record
Abstract
Numerous recent epidemiological studies have linked health effects with short-term exposure to air pollution levels commonly found in North America. The association between two key pollutants—ozone and fine particulate matter— and mortality in 12 Canadian cities was explored in a time-series study. City-specific estimates were obtained using Poisson regression models, adjusting for the effects of seasonality and temperature. Estimates were then pooled across cities using the inverse variance method. For a 10 ppb increase in 1-hr daily maximum ozone levels, significant associations were in the range of 0.56% - 2.47% increase in mortality. For a 10 μg/m3 increase in the 24-hr average PM2.5 concentration of, significant associations varied between 0.91% and 3.17% increase in mortality. Generally, stronger associations were found among the elderly. Effects estimates were robust to adjustment for seasonality, but were sensitive to lag structures. There was no evidence for effect modification of the mortality-exposure association by city-level ecologic covariates.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".