| Epidemiological studies have found that exposure to elevated concentrations of atmospheric particulate matter (PM) can cause adverse human health effects. Due to limited atmospheric PM pollution studies in Texas, U.S., this dissertation aims to systematically study the PM spatial/temporal variation, morphology, chemical composition and human exposure through monitoring and modeling in the Houston and Corpus Christi areas.;Field campaigns were conducted to quantify the concentration level, spatial/temporal variation, morphology, and chemical composition of PM in the study cities. The average fine particle with aerodynamic diameter ≤ 2.5 mum (PM 2.5) and ultrafine particle with aerodynamic diameter ≤ 100 nm (UFP) concentration levels were determined as 12.8 mug m-3 and 16,361 ;Empirical exponential decay functions were built to characterize the particle dispersion and spatial distribution at the roadsides. The CALINE4 dispersion model was modified by a distance dependent function to predict the UFP at roadsides. The distance was from the receptor to the emission source of roadway. Four land use regression models were developed for PM2.5 and UFPs (overall adjusted R2>54%) to identify particle sources and to quantify the spatial variations. Final predictors of the LUR model contained meteorological variables, land use types, total population, Hispanic group density, total road/major road length density, household income and elevation.;The PM pollution exposure disparity associated with socioeconomic parameters was estimated by statistical analyses. PM intake fraction (iF) and deposition were simulated using PM exposure concentration, human activity pattern, and PM deposition rate. The results indicated PM2.5 and UFP concentration levels were statistically associated with certain socioeconomic variables, including Hispanic population, education, income, traffic and road length (overall R>0.2, p<0.05). The estimates of UFP iF (ratio of intake to emission) were 6-8 per million. The estimates of PM2.5 and UFP respiratory deposition for the residents in the study areas were estimated at 80-3,000 g day-1 and 108-1011;Even though this dissertation focused on Texas particle pollution, the experimental and modeling methodology are applicable to other regions, as well as the concepts of iF and deposition. For instance, the integration of air pollution data and modeling within the Geographic Information System framework, the novel models developed to determine particle dispersion and concentrations and the methods of geo-statistical analysis are unique approaches, which can be applied globally to investigate ambient PM pollution. Additionally, the concepts of particle iF and deposition help to assess the public health risk of exposure to air pollutants that can be used as a tool to assist the public health policy decision-making process.;Key Words: Particulate Matters, Exposure Disparity, Exponential Decay Function, Land Use Regression Model, Particle Morphology, Particle Chemical Composition, Respiratory Deposition, Modified CALINE4 Model, Intake Fraction. |
