Date of Award
Master of Public Health (MPH)
Dr. Christina Fuller
Dr. Lisa Casanova
INTRODUCTION: The aim of this study is to explore elements of the built environment related to transportation, including state and interstate roads, railroads, daily traffic and bus stops and their relationship to ambient nitrogen dioxide (NO2)levels. Taking place in predominantly African American communities of Atlanta across more affluent and poorer census tracts, this study also considered SES demographics. This study will pay particular attention to identify associations between NO2 levels and proximity to bus stops.
METHODS: NO2 data (ug/kg) was sampled in 2013 and distance to transportation was estimated. SES data was taken from the 2010 American Community Survey (ACS) at the block group level for the 17 block groups where NO2 readings were taken. A multiple linear regression was modelled to test the relationship between NO2 and distance from roads, bus stops, railroads, and attributes such as average daily traffic while controlling for SES variables.
RESULTS: In multivariable models, controlling for each variable through stepwise selection, variance was attributed more so to site distance to state road (m) (β=-0.1564; CI (-0.2114, -0.1014)), distance from bus stops (β=-1.3226; CI(-2.0459, -0.5993)), and average annual daily vehicle counts (β=0.00178; CI (0.000484, 0.00308)), than to demographic differences. Once controlling for traffic variables, no SES variables where selected into the model. Using the maximum r-squared approach to variable selection, the final model included 3 variables and an adjusted r-squared of 0.3835.
DISCUSSION: We were able to identify elements of the built environment that contribute to the increase of NO2 in an urban area. Results show that factors such as proximity to roads and bus stops plays a statistically significant role in increased NO2 readings. While exploratory in nature, and despite stated limitations, we were able to identify a statistically significant association between bus stops, state roads and daily traffic counts and increased NO2 levels.
Alhonaiti, Tareq, "Public Transit and Ambient Nitrogen Dioxide (NO2) Levels in Four Atlanta Neighborhoods." Thesis, Georgia State University, 2020.
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