Establishment of a NORM baseline for selected seafood in the Gulf of Mexico

Naturally occurring radioactive material was characterized in selected seafood samples from three areas in the Gulf of Mexico. Relatively desirable and abundant fish such as Red Snapper, Red Drum, Northern Whiting, and Spotted Trout as well as oysters were collected and analyzed using gamma spectroscopy to determine the concentration of 228Ra, 226Ra, and 40 K. Average total activity concentration from these radionuclides were 0.9 ± 0.6, 1.6 ± 1.2, and 132 ± 57 Bq kg−1 respectively, in the edible portion of wet weight samples. The results were consistent with previous studies for other bodies of water. A small but statistically significant increase in 226Ra was found in comparison to similar research performed 20 years prior. These measurements provide a reasonable baseline for the examined species from the Gulf of Mexico. •A statistically significant increase in 226Ra was found compared to a regional work 20 years prior.•Oyster species appear to have a higher activity concentration of 226Ra and 228Ra than the fish species analyzed.•These data present an important baseline for future use in environmental concerns.