Exposure of chronic obstructive pulmonary disease patients to particulate air pollution : an assessment of respiratory health effects
Bibliographic record
Abstract
Epidemiological studies suggest associations between particulate air pollution and health effects, including decreased lung function, and increased respiratory symptoms and medication use. Studies also suggest that persons with cardiopulmonary disease may be at increased risk for particle-related health effects. This study measured personal and ambient fine particulate (PM₂.₅) and sulfate concentrations for chronic obstructive pulmonary disease (COPD) patients, and evaluated the relationships between exposure and lung function, respiratory symptoms, and medication use. This study was conducted during the summer of 1998 in the Greater Vancouver Regional District, British Columbia. Sixteen (7 male, 9 female) non-smoking COPD patients (mean age: 74, range: 54-86) were recruited from the Vancouver Hospital Respiratory Clinic (13) and B.C. Lung Association (3). Each subject was equipped with a PM₂.₅ monitor, activity diary, and medication log for seven 24-hour periods (approximately 1.5 weeks apart). Before and after sampling periods, subjects performed forced expiratory maneuvers using portable spirometers. Following sampling periods, subjects completed symptom questionnaire interviews. Ambient PM₂.₅ measurements were obtained on days corresponding to personal sampling at 5 sites within the study area. All samples were analyzed for PM₂.₅ mass and sulfate concentrations. Mean personal and ambient PM₂.₅ (and sulfate) levels were 18 and 11 (1.5 and 1.9) μg/m³, respectively. No associations between air pollution and respiratory health outcomes were statistically significant. However, weighted regression analyses suggest that up to a 1% decline in FEVi may be associated with each 10 pg/m3 increase in ambient PM₂.₅ , and 0.27- 1.04% declines in FEVi may be associated with each μg/m³ increase in personal and ambient sulfate. These associations were not observed with respect to personal PM₂.₅ exposure, suggesting that ambient PM₂.₅, personal sulfate, and ambient sulfate were more strongly associated with adverse health effects than was personal PM₂.₅. Ozone also appeared to be associated with decreased FEVi. Consequently, it was not possible to differentiate between the effects of particulates and ozone. No consistent associations were observed between any exposure measure and symptom severity or bronchodilator use. Major limitations of this study included the small degree of variability in exposure, and the quality of symptom questionnaire and bronchodilator use data.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 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".