Traffic, Air Pollution, Built Environment and Obesity in Greater Houston

Where we live affects our health. This dissertation examines the urban environment–in particular, the traffic-related air pollution and built environment, in a perspective of public health. And also, this dissertation investigated the association between individual environmental factor and multiple types of adverse health effects. Three major components of the urban environment were investigated in this dissertation including traffic congestion, traffic-related air pollution, and built environment. For the traffic congestion, we investigated the increase of multiple types of public health outcomes in association with the air pollution emitted during traffic congestion in the Greater Houston Area. For the traffic-related air pollution and built environment, we studied their associations with obesity in a group of Mexican Americans living in the Greater Houston Area. The demographic information and health status of our study participants were collected by the MD Anderson Mano a Mano Mexican American Cohort. The study participants generally have low socio-economic status and were sampled from census tracts with high poverty rate. We consider this study group as a vulnerable population, who are highly sensitive to changes of their living environment. This dissertation is advanced in exposure assessment. The traffic congestion was predicted based on the updated traffic data and emission data considering various influential factors, such as road type, vehicle classification, model year, and local weather. The exposure to traffic-related air pollution was estimated using a state-of-art dispersion model. The assessment of built environment was cost-effect given the tools (e.g. Google Maps) used. The advanced exposure assessment enables us to objectively capture the individual variation in exposure to the traffic-related air pollution and built environment. This dissertation revealed several pieces of evidence indicating significant public health impacts of the studied exposure variables. The congestion-related air pollution was estimated to cost four to ten million dollars of healthcare during the five-year study period. Living close to highway was statistically significantly associated with higher BMI in Mexican Americans. Both road connection and recreational parks were statistically significantly associated with BMI in Mexican Americans, thus to provide a highly “walkable”, safe, attractive built environment was still crucial for obesity prevention. Those results can provide references for policymaking and urban planning in Houston and other U.S. cities