Multi-pollutant Mobile Platform Measurements of Traffic-associated Air Pollutants Adjacent to the I-40 Corridor in Albuquerque, NM

摘要

Background: Living in close proximity to major roadways has consistently been identified as a risk factor for adverse health outcomes associated with exposure to fine particle air pollution. However, current approaches to measuring exposure to ambient air pollution that rely on a limited number of fixed-site monitors likely underestimate near-roadway exposures, particularly when they are sited based on regulations designed to characterize regional-scale concentrations. This can lead to differential misclassification of exposure in epidemiological studies. Objective: Use a multi-pollutant mobile monitoring platform developed by the University of Washington Center for Clean Air Research to determine the composition and spatial extent of traffic-associated air pollution in two residential neighborhoods along the I-40 corridor of Albuquerque, NM. Results: Daily monitoring using the mobile platform took place on 7 afternoons in April 2012 and consisted of simultaneous measurements of 16 unique pollutants at a sampling frequency of 10 seconds. We found that NOx, black carbon, CO2 and particles smaller than 1 μm were significantly elevated at the edge of the roadway, whereas particles greater than 1 μm were not elevated. A significant depletion of ozone concentrations was also observed, consistent with titration of O3 with vehicle-derived NO. All pollutants returned to background levels within 300m of the edge of the roadway. Conclusions: Mobile monitoring can efficiently capture the spatial patterns for multiple pollutants arising from a single line source, and the inter-relationships among those pollutants. This capability will allow for the identification of multi-pollutant mixtures associated with traffic sources and their variability in complex urban settings. The improved understanding of near-roadway air pollution may facilitate more reliable assignment of near-roadway exposures for use in epidemiological studies.