Long-Term Exposure to Traffic-Related Air Pollution in Relation to Physical Disability and Its Progression in Older Age

Long-Term Exposure to Traffic-Related Air Pollution in Relation to Physical Disability and Its Progression in Older AgeAbstract Number:2197 Jennifer Weuve*, Joel Kaufman, Adam Szpiro, Cynthia Curl, Robin Puett, Todd Beck, Denis Evans, and Carlos Mendes de Leon Jennifer Weuve* Rush Institute for Healthy Aging, United States, E-mail Address: [email protected] Search for more papers by this author , Joel Kaufman University of Washington, United States, E-mail Address: [email protected] Search for more papers by this author , Adam Szpiro University of Washington, United States, E-mail Address: [email protected] Search for more papers by this author , Cynthia Curl University of Washington, United States, E-mail Address: [email protected] Search for more papers by this author , Robin Puett University of Maryland, United States, E-mail Address: [email protected] Search for more papers by this author , Todd Beck Rush Institute for Healthy Aging, United States, E-mail Address: [email protected] Search for more papers by this author , Denis Evans Rush Institute for Healthy Aging, United States, E-mail Address: [email protected] Search for more papers by this author , and Carlos Mendes de Leon University of Michigan, United States, E-mail Address: [email protected] Search for more papers by this author AbstractPhysical disability is common but not inevitable in older age. It represents the combined impact of often co-morbid chronic diseases and subclinical processes on a person’s ability to perform activities that are essential for self-care and independent living. Exposure to air pollution causes multiple adverse health effects—e.g., increased cardiovascular and respiratory risks—that contribute to the development and progression of disability. In a large cohort of older adults (N=5725) living in Chicago, we investigated long-term exposure to traffic-related air pollution in relation to physical disability and its progression. We used a very finely resolved GIS-based spatio-temporal smoothing model developed for Chicago (cross-validation R2=0.87), incorporating community-based monitoring, to estimate concentrations of ambient oxides of nitrogen (NOx) at all participants’ residential locations. To estimate participants’ long-term NOx exposure, we averaged concentrations over 5 years starting in 1999 or enrollment, whichever was earlier. We analyzed this exposure in relation to subsequent change in lower-extremity physical function, which was assessed every 3 years via the tandem stand, chair stand, and timed walking speed. In multivariable-adjusted analyses weighted to account for attrition over follow-up, higher long-term NOx exposure was associated with significantly faster progression in disability. Compared with participants in the lowest quartile of NOx exposure, disability progressed among those in the highest exposure quartile at a rate that was faster by -0.24 unit/y (95% CI, -0.40 to -0.09) or about 67% faster. The association was linear across the continuum of NOx exposure: per 10 ppb-increment in exposure, the rate of disability progression was -0.17 unit/y faster (95% CI, -0.28 to -0.06). These data join a growing body of evidence suggesting that traffic-related air pollution exposures may adversely affect aging-related declines in health.