Abstract
Very little knowledge is available on the concentration of the more toxic oil spill chemicals (OSCs) that are present in human exposure zones. To fill this knowledge gap, this dissertation evaluates time-space specific concentrations of OSCs of health concern in environmental matrices (weathered oil, sediments, ocean water, and air) which represent human exposure zones along coastal areas. This dissertation integrates knowledge from physical oceanography, geospatial technology, environmental chemistry, engineering sampling, and statistical analysis to estimate OSCs concentrations. Three different studies were conducted to accomplish the objective. First, the output of an oil trajectory model was utilized to categorize nearshore sampling data of OSC concentrations within time-space specific categories: prior to oil spill impact, post oil spill impact, and within unimpacted areas. Differences among these categories were then evaluated statistically. The second approach used weathered oil slick samples collected along the Gulf Coast and estimated their age-at-sea with the oil spill module of the Connectivity Modeling System to determine the relationship between PAH depletion and oil slick weathering at sea. The third approach evaluated whether changes in air quality due to the 2010 DWH disaster were captured by aerosol optical depth (AOD) derived using satellite data and by ground-based monitoring of air pollution. Collectively these studies provide concentrations of OSCs of health concern in environmental matrices which represent human exposure zones. The concentrations derived through these studies can be used to increase the certainty of human health risk estimates. The methods proposed in these studies may be used to interpret environmental sampling results to improve the management of future oil spills. Future work is suggested to expand the capacity of existing models to predict individual concentrations of OSCs of health concern. Finally, the development of a fully coupled Oil Spill Fate and Transport-Atmospheric Chemical Transport Model is recommended.