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Updated: Jun 4, 2026
13:28
Methodology for Sputum Induction and Laboratory Processing
Published on: December 17, 2017
Association between proximity to major roads and sputum cell counts
Julie Wallace1, Liesel D'silva, John Brannan
1Centre for Spatial Analysis, School of Geography and Earth Sciences, St Joseph's Healthcare and Department of Medicine, McMaster University, Hamilton, Ontario.
Canadian Respiratory Journal
|March 4, 2011
Summary
Living near highways increases the risk of neutrophilic bronchitis and asthma diagnoses. Proximity to major roads is linked to asthma exacerbations and reduced lung function, especially in women.
Area of Science:
- Environmental Health
- Pulmonary Medicine
- Epidemiology
Background:
- Motor vehicle emissions are linked to obstructive airway diseases.
- The specific impact of traffic proximity on bronchitis requires quantification.
Purpose of the Study:
- To investigate the association between proximity to major roads/highways and sputum neutrophils/eosinophils.
- To evaluate the effect of road proximity on asthma patients' spirometry and exacerbations.
Main Methods:
- Retrospective study of 485 sputum cell counts.
- Geographic information system (GIS) software used to geocode patient residences.
- Multinomial logistic and multivariate linear regression analyses adjusted for confounders.
Main Results:
- Living within 1000m of highways increased bronchitis risk (OR 3.8), particularly neutrophilic bronchitis (OR 4.7).
- Increased risk of asthma diagnosis (OR 1.9) for those near highways.
- Living within 300m of major roads correlated with asthma exacerbations (OR 1.9) and lower lung function, notably in women.
Conclusions:
- Proximity to highways/major roads is associated with neutrophilic bronchitis in patients with airway diseases.
- Living near traffic increases asthma diagnosis risk, exacerbations, and lowers lung function.
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