Mortality in Relation to Primary Roadway Proximity

Background: Our aim was to evaluate respiratory mortality among adults ages 25-65 years with respect to residential proximity to primary roadway such as freeways and highways in Los Angeles and Sacramento counties from 1999–2001.

Methods: Mortality data for those ages 25-65 years in Sacramento and Los Angeles Counties were obtained from the California Department of Health Services. Respiratory mortality was defined by ICD-10 codes J00-J98. Logistic regression was used to determine adjusted odds ratios (OR) and 95% confidence intervals (CI) to investigate the relationships between major roadway proximity and proportionate mortality. The resulting odds ratios were adjusted for age, race and gender. Roadway proximity was categorized into <150, 150 to <300, 300 to <500, 500 to < 1,000 and 1000 to 2500m.

Results: The adjusted odds of respiratory mortality for living within 150 m was 24% and 29% higher than the odds for those living within 1000 to 2500 m of major roadways in Los Angeles and Sacramento, respectively. The oldest age group (55-65 years) had the highest incidence of death from respiratory related causes. The adjusted odds of respiratory mortality in females were 31% higher than for males.

Conclusions: Our results provide evidence that primary roadway proximity can be linked to respiratory mortality and suggest that freshly emitted pollutants from gasoline and diesel vehicles may have negative impacts on the respiratory system.