Air pollution
Canadian ED visits track CO, NO2, ozone, and PM
Open access · cc by · source: Europe PMC
In seven Canadian cities, carbon monoxide and NO2 align with cardiac emergency visits, ozone with respiratory visits, and particles with warm-season asthma.
Study at a glance
- Design
- Other — Multi-city daily time-series of ED visits vs gaseous and particulate pollutants
- N
- N=400000 · Nearly 400,000 ED visits to 14 hospitals in seven Canadian cities
- Population
- Cardiac and respiratory emergency department visits in seven Canadian cities
- Outcome
- ED visit associations with CO, NO2, O3, SO2, and PM by season and lag
Structured fields used in claim comparison tables when every cited study has a complete layer.
Key findings
CO and NO2 showed the most consistent cardiac associations (e.g., warm-season CO: +5.2% MI/angina per 0.7 ppm). Ozone tracked asthma and COPD (COPD +6.2% per 18.4 ppb in the warm season). Warm-season PM10 and PM2.5 were strongly linked to asthma visits. Three-hour same-day averages showed no consistent signal.
Methodology
Authors pooled daily time-series of ED visits from 14 hospitals in seven cities, linking CO, NO2, O3, SO2, PM10, and PM2.5 at lags 0–2 days (and 3-hour averages) to cardiac and respiratory diagnoses after weather adjustment.
Limitations
Edmonton supplied ~70% of visits, children’s hospitals were missing in most cities, and the design cannot assign personal exposure or prove a single causal pollutant among correlated gases.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
Pooled daily ED visits from 14 hospitals in seven Canadian cities linked CO, NO₂, O₃, SO₂, PM₁₀ and PM₂.₅ at lags 0–2 days (and 3-hour averages) to cardiac and respiratory diagnoses. CO and NO₂ showed the most consistent cardiac associations (warm-season CO: +5.2% MI/angina per 0.7 ppm). Ozone tracked asthma and COPD (COPD +6.2% per 18.4 ppb in the warm season). Warm-season PM₁₀ and PM₂.₅ were strongly linked to asthma visits. Three-hour same-day averages showed no consistent signal. Edmonton supplied ~70% of visits.
Evidence for the claim as stated.
City hospital series do not agree on which pollutant or lag carries the acute signal. Nicosia finds same-day PM₁₀ for all-cause admissions (0.85% per 10 μg/m³) and lag-1 ozone for cardiovascular admissions (2.91% per 10 ppb) but no overall PM₁₀–respiratory link. Canadian EDs find CO/NO₂ most consistent for cardiac diagnoses and ozone for asthma/COPD, with 3-hour averages null and Edmonton dominating the sample. Medicare finds PM₂.₅ mass plus composition for CVD, MI and respiratory admissions among those 65+. Treating 'time series show pollution raises admissions' as one coefficient hides those splits.
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
City hospital series do not agree on which pollutant or lag carries the acute signal. Nicosia finds same-day PM₁₀ for all-cause admissions (0.85% per 10 μg/m³) and lag-1 ozone for cardiovascular admissions (2.91% per 10 ppb) but no overall PM₁₀–respiratory link. Canadian EDs find CO/NO₂ most consistent for cardiac diagnoses and ozone for asthma/COPD, with 3-hour averages null and Edmonton dominating the sample. Medicare finds PM₂.₅ mass plus composition for CVD, MI and respiratory admissions among those 65+. Treating 'time series show pollution raises admissions' as one coefficient hides those splits.
Related papers in this topic
Same topic cluster — not a recommendation engine.