A prospective evaluation of air quality and workers' health in broiler and layer operations
Bibliographic record
Abstract
OBJECTIVES: In developed countries, poultry are raised in totally confined buildings in which workers are exposed to indoor airborne contaminants. A prospective study was conducted to investigate the relationship between workers' respiratory health and airborne contaminants during the life cycle of broiler and layer flocks. METHODS: Seventeen layer and 16 broiler operations were chosen within a 200 km radius of Edmonton. An attempt was made to visit each broiler operation twice during the winter and summer seasons in the early and later periods of the 6-week production cycle and visit each layer operation three times during the early, middle and later periods of the 40-week production cycle. RESULTS: In broiler operations, respirable particle counts, total dust and endotoxin concentrations, and ammonia levels increased with flock age, while mean endotoxin load (EU/mg) decreased in the winter and summer seasons. Increases in dust and endotoxin concentrations in the winter season were not statistically significance. Mean endotoxin concentration increased and mean dust concentration and ammonia level decreased with flock age in layer operations, although not all these changes were statistically significant. Mean across-shift decrements in FEV(1) and FVC increased with flock age among workers from layer operations. Endotoxin concentration was significantly associated with across-shift changes in FEV(1) among workers in layer operations. CONCLUSION: In our study, changes in lung function appear more closely associated with changes in endotoxin than other contaminants. Changes in indoor environmental conditions occurring in poultry barns which are dependent on the flock age may affect workers' health in poultry operations.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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".