Authorities subsequently detected elevated levels of the radioisotope Cesium-137 (Cs-137) in containers in Los Angeles, Miami, Houston, and Savannah.

The U.S. Food and Drug Administration (FDA) issued a warning that Great Value brand shrimp sold at Walmart in 12 U.S. states contained unsafe levels of the radioactive isotope cesium-137.

Specifically, the FDA warns that the main health concern from such long-term exposure to Cs-137 "is an elevated risk of cancer, resulting from damage to DNA within living cells of the body."