Doctor of Philosophy (PhD)


Environmental Science

Document Type



Radioactive disintegration of naturally occurring radioactive material was modeled with high precision and no assumptions to better understand serial decay in high order disequibrlia. This model helped develop a new method of quick analysis of NORM, where radioactivity can be measured with reasonable certainty before secular equilibrium is established. This approach was a significant improvement on previous similar approaches, halving time required for the same results and reduced wait time compared to classical approaches by 92%. Consequentially, NORM was measured in selected seafood samples from three areas in the Gulf of Mexico. Red Snapper, Red Drum, Northern Whiting, Spotted Trout and oysters were collected and analyzed using gamma spectroscopy. The average radioactivity concentration from these radioisotopes were 0.9 ± 0.6, 1.6 ± 1.2, and 132 ± 57 Bq kg-1, respectively for 228Ra, 226Ra, and 40K in wet weight muscle tissue samples (edible portion). These findings were in general consistency with previous research from other bodies of water. However, when compared to research performed in the Gulf of Mexico 20 years prior, a slight increase in radioactivity concentration of 226Ra was found. These measurements of radioactivity concentration provide a reasonable baseline for the species examined from the Gulf of Mexico.



Committee Chair

Wilson, Vince