Superfund Research Program
Dynamic Exposure Pathways Under Conditions of Environmental Emergencies
- Project Summary
Sampling of marine sediments has continued in Year three. The extensive flooding of Houston Ship Channel (HSC) and Galveston Bay (GB) from Hurricane Harvey scoured surface sediment. Microtox measurements are used to prescreen sediment samples before targeted analysis by GC/QQQ, LC/QQQ and GC/GC/MS. Over the year, sediment samples were taken for analysis for organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), as well as heavy metal and mercury data. Historical archives were data mined allowing the researchers to develop a reference baseline dataset for future sampling events and understand the impact of Hurricane Harvey.
All sediment data have been modeled through spatial regression models and Kriged maps of each of contaminant have been produced. A computer model for predicting waves, water levels, currents, and sediment motion due to Hurricane Ike was developed. Hurricane Ike simulations were compared to measured water levels were good. This gives the research team confidence the characteristics of the region are well represented in the model. In a similar computer model setup, an artificial wind was run over GB and the amount of sediment motion tracked where it was determined the sediment collected on the land. The impact of this is to show, under strong wind forcing, it is possible for sediment to overflow from GB onto land. In addition to the traditional contaminants, the researchers have developed new methods for emerging contaminants such as per- and polyfluoroalkyl substances (PFAS) and pharmaceutical and personal care products (PPCP) and have ongoing time series starting since September 2017 for water and sediment samples from Galveston Bay.