High-resolution mapping of traffic related air pollution with Google street view cars and incidence of cardiovascular events within neighborhoods in Oakland, CA.
BACKGROUND
Some studies have linked long-term exposure to traffic related air pollutants (TRAP) with adverse cardiovascular health outcomes; however, previous studies have not linked highly variable concentrations of TRAP measured at street-level within neighborhoods to cardiovascular health outcomes.


METHODS
Long-term pollutant concentrations for nitrogen dioxide [NO2], nitric oxide [NO], and black carbon [BC] were obtained by street-level mobile monitoring on 30 m road segments and linked to residential addresses of 41,869 adults living in Oakland during 2010 to 2015. We fit Cox proportional hazard models to estimate the relationship between air pollution exposures and time to first cardiovascular event. Secondary analyses examined effect modification by diabetes and age.


RESULTS
Long-term pollutant concentrations [mean, (standard deviation; SD)] for NO2, NO and BC were 9.9 ppb (SD 3.8), 4.9 ppb (SD 3.8), and 0.36 μg/m3 (0.17) respectively. A one SD increase in NO2, NO and BC, was associated with a change in risk of a cardiovascular event of 3% (95% confidence interval [CI] -6% to 12%), 3% (95% CI -5% to 12%), and - 1% (95% CI -8% to 7%), respectively. Among the elderly (≥65 yrs), we found an increased risk of a cardiovascular event of 12% for NO2 (95% CI: 2%, 24%), 12% for NO (95% CI: 3%, 22%), and 7% for BC (95% CI: -3%, 17%) per one SD increase. We found no effect modification by diabetes.


CONCLUSIONS
Street-level differences in long-term exposure to TRAP were associated with higher risk of cardiovascular events among the elderly, indicating that within-neighborhood differences in TRAP are important to cardiovascular health. Associations among the general population were consistent with results found in previous studies, though not statistically significant.
['Alexeeff|Stacey E|SE|', 'Roy|Ananya|A|', 'Shan|Jun|J|', 'Liu|Xi|X|', 'Messier|Kyle|K|', 'Apte|Joshua S|JS|', 'Portier|Christopher|C|', 'Sidney|Stephen|S|', 'Van Den Eeden|Stephen K|SK|']
D000328:Adult D000368:Aged D000393:Air Pollutants D000397:Air Pollution D002140:California D002318:Cardiovascular Diseases D002947:Cities D015331:Cohort Studies D005260:Female D062305:Geographic Mapping D006801:Humans D015994:Incidence D008297:Male D008875:Middle Aged D012111:Residence Characteristics D012189:Retrospective Studies D000076764:Traffic-Related Pollution D001335:Vehicle Emissions D055815:Young Adult
Air pollution Mobile monitoring Cardiovascular disease Coronary heart disease Mortality