Background: Few studies have evaluated the influence of the residential environment on stroke severity. 
Objectives: We assessed the association of residential ambient fine particulate matter air pollution (PM2.5), noise, and surrounding greenspace with initial stroke severity. 
Methods: We obtained data on patients hospitalized with acute ischemic stroke from a hospital-based prospective stroke register (2005-2014) in Barcelona. Assessment of spatiotemporal exposure to PM2.5 was based on a land use regression model developed in the European Study of Cohorts for Air Pollution Effects. Residential surrounding greenspace was estimated as the average of satellite-based Normalized Difference Vegetation Index (NDVI) within a 300 m buffer of the residence. We abstracted daily, evening, night and average noise level at the street nearest to the residential address, using strategic noise map of Barcelona. Stroke severity was assessed using the NIHSS (dichotomous and continuous). We used binomial and logistic regression models to evaluate the associations of noise, greenspace and PM2.5, with stroke severity adjusting for patient demographics and traditional cardiovascular risk factors. 
Results: 2761 cases were included. Higher residential surrounding greenspace was associated with lower risk of severe stroke (OR for NIHSS>5, 0.72; 95% CI: 0.62-0.85). Conversely, living in areas with higher evening noise had a higher risk of severe stroke (OR, 1.20; 95% CI: 1.02-1.41). PM2.5 was not associated with initial stroke severity.
Conclusions: In an urban setting, neighborhood greenspace and traffic noise are associated with initial stroke severity, suggesting an important influence of the built environment on the global burden of stroke.

ASSOCIATION OF RESIDENTIAL AIR POLLUTION, NOISE, AND NEIGHBOURHOOD GREEN SPACE WITH INITIAL STROKE SEVERITY