Texas A&M University
Bissett, Wesley Thurlow, Jr.
Ecosystem health at the texas coastal bend: a spatial analysis of exposure and response.
Degree: PhD, Veterinary Microbiology, 2009, Texas A&M University
This dissertation investigated locational risks to ecosystem health associated with
proximity to industrial complexes. The study was performed at the behest of ranchers
and citizens living and working down-prevailing wind from the Formosa Plastics, Inc.
and ALCOA facilities located in Calhoun County, Texas. Concerns expressed were for
potential genotoxicity resulting from exposure to complex chemical mixtures released by
the facilities. Exposure assessment of the marine environment was performed with
sediments and oysters from Lavaca Bay being analyzed. Numerous chemicals were
found to be present at concentrations considered likely to result in adverse responses in
exposed populations. Bayesian geostatistical analysis was performed to determine if the
concentrations were affected by a spatial process. Mercury and polycyclic aromatic
hydrocarbons were the most notable of the chemicals found to be present at elevated
concentrations and affected by a spatial process. Evaluation of maps generated from
spatial modeling revealed that proximity to ALCOA resulted in elevated risks for
exposure to harmful concentrations of pollutants. Genotoxicity was measured in two
sentinel species. Oysters (Crassostrea virginica) were utilized for evaluation of the
marine environment and cattle (Bos taurus and Bos taurus crossbred cattle) were chosen
for evaluation of the terrestrial environment. Chromosomal aberration analysis was
performed on oyster hematocytes. Analysis of the results failed to demonstrate the
presence of an important generalized spatial process but some specific locations close to
the ALCOA plant had elevations in this measure of genotoxicity. Stress as measured by
the lysosomal destabilization assay was also performed on oyster hematocytes. These results were found to be affected by a significant spatial process with the highest degree
of destabilization occurring in close proximity to ALCOA. Genotoxicity in cattle was
evaluated with the single cell gel electrophoresis assay and chromosomal aberration
analysis. Bayesian geostatistical analyis revealed the presence of important spatial
processes. DNA-protein cross-linkage was the most notable with a strong indication of
increased damage down-prevailing wind from the industrial complexes. Results
indicated that proximity to industrial facilities increased the risk for harmful exposures,
genotoxicity, and lysosomal destabilization.
Advisors/Committee Members: Adams, L. Garry (advisor), Thompson, James A. (advisor), Field, Robert (committee member), Moyer, William (committee member), Phillips, Timothy (committee member), Scott, H. Morgan (committee member).
Subjects/Keywords: genotoxicity; sentinnel species; biomarkers; spatial analysis; Bayesian analysis
to Zotero / EndNote / Reference
APA (6th Edition):
Bissett, Wesley Thurlow, J. (2009). Ecosystem health at the texas coastal bend: a spatial analysis of exposure and response. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2126
Chicago Manual of Style (16th Edition):
Bissett, Wesley Thurlow, Jr. “Ecosystem health at the texas coastal bend: a spatial analysis of exposure and response.” 2009. Doctoral Dissertation, Texas A&M University. Accessed January 24, 2021.
MLA Handbook (7th Edition):
Bissett, Wesley Thurlow, Jr. “Ecosystem health at the texas coastal bend: a spatial analysis of exposure and response.” 2009. Web. 24 Jan 2021.
Bissett, Wesley Thurlow J. Ecosystem health at the texas coastal bend: a spatial analysis of exposure and response. [Internet] [Doctoral dissertation]. Texas A&M University; 2009. [cited 2021 Jan 24].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2126.
Council of Science Editors:
Bissett, Wesley Thurlow J. Ecosystem health at the texas coastal bend: a spatial analysis of exposure and response. [Doctoral Dissertation]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2126