In a recent urban multiethnic cohort study, there was evidence supporting that within-city variation in residential proximity to a major roadway is associated with higher risk of ischemic stroke. However, an individual’s smoking history modified this association, with the association remaining only among participants not currently smokers. Subjects (n=3,287) participated in NOMAS (The Northern Manhattan Study), an ongoing, population-based cohort study designed to measure cardiovascular risk factors, stroke incidence, and other outcomes in a multiethnic urban population. Recruitment occurred from 1993 to 2001 and participants are followed-up annually by telephone. Researchers found:

• During a median follow-up period of 15 years, 11% of participants were diagnosed with ischemic stroke.
• Participants living <100 m from a roadway had a 42% higher rate of ischemic stroke vs those living >400 m.
• This association was more pronounced among noncurrent smokers and not evident among smokers.
• There was no clear pattern of association between proximity to major roadways and other cardiovascular events including myocardial infarction, all-cause death, or vascular death.