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Download fileFactors Influencing Mobile Source Particulate Matter Emissions-to-Exposure Relationships in the Boston Urban Area
journal contribution
posted on 2007-11-15, 00:00 authored by Susan L. Greco, Andrew M. Wilson, Steven R. Hanna, Jonathan I. LevyBenefit−cost and regulatory impact analyses often use
atmospheric dispersion models with coarse resolution to
estimate the benefits of proposed mobile source emission
control regulations. This approach may bias health
estimates or miss important intra-urban variability for
primary air pollutants. In this study, we estimate primary
fine particulate matter (PM2.5) intake fractions (iF; the fraction
of a pollutant emitted from a source that is inhaled by
the population) for each of 23 398 road segments in the
Boston Metro Core area to evaluate the potential for intra-urban variability in the emissions-to-exposure relationship.
We estimate iFs using the CAL3QHCR line source model
combined with residential populations within 5000 m of each
road segment. The annual average values for the road
segments range from 0.8 to 53 per million, with a mean of
12 per million. On average, 46% of the total exposure is
realized within 200 m of the road segment, though this varies
from 0 to 93% largely due to variable population patterns.
Our findings indicate the likelihood of substantial intra-urban variability in mobile source primary PM2.5 iF that
accounting for population movement with time, localized
meteorological conditions, and street-canyon configurations
would likely increase.