Mobile monitoring of traffic-related air pollution for a prospective cohort study in the greater Seattle area

Abstract

AbstractGrowing evidence links traffic-related air pollution (TRAP) to adverse health effects. Previous air pollution studies focused on a few commonly measured pollutants with poor spatial resolution. Well-designed mobile monitoring studies may address this limitation. We designed an extensive mobile monitoring campaign to characterize TRAP exposure levels for a Seattle-based cohort, the Adult Changes in Thought (ACT) study. The campaign measured particulate matter ≤ 2.5 µm in diameter (PM2.5), ultrafine particulates (UFP), black carbon (BC), nitrogen dioxide (NO2) and carbon dioxide (CO2) at 309 stop locations representative of the cohort. We collected about 29 two-minute measures at each location during all seasons, days of the week, and most times of day for a one-year period. Annual average concentrations of UFPs had similar degrees of spatial variability as BC and NO2 but higher degrees of variability as CO2 and PM2.5. UFPs had less temporal variability than other pollutants. Validation showed good agreement between our BC, NO2, and PM2.5 measurements and regulatory monitoring sites. The results from this campaign will be used to assess TRAP exposure in the ACT cohort.SynopsisWe assessed annual-average traffic-pollutant levels with high spatial resolution at locations representative of participant residences using a temporally balanced short-term mobile monitoring campaign.Abstract Figure