The risk from the recalled shrimp is “quite low,” said Donald Schaffner, a food safety expert at Rutgers University.

The FDA detected Cesium-137, a radioactive isotope, in one shipment of Great Value frozen raw shrimp to Walmart.

The amount contained in the tested shipment held by the FDA was not enough to pose acute harm to consumers, exposure over time could pose an elevated risk of cancer by damaging living cells in the bo...