The US Food and Drug Administration (FDA) on Monday warned consumers not to eat certain frozen shrimp products sold at Walmart after tests revealed possible contamination with Cesium-137, a radioactive isotope. Federal officials said three lots of Great Value brand frozen shrimp were pulled from Walmart stores after the isotope was detected in shipping containers and a sample of breaded shrimp imported from Indonesia. “If you have recently purchased raw frozen shrimp from Walmart that matches this description, throw it away,” FDA officials said in a statement.Walmart has recalled frozen, raw shrimp sold in 13 states following the warning, the Associated Press reported.

What is Cesium-137, why is it harmful?

Cesium-137, also known as Cs-137, is a byproduct of nuclear reactions, including nuclear weapons testing, reactor operations and nuclear accidents. It is the most common radioactive isotope of cesium, according to the US Environmental Protection Agency (EPA). Cs-137 is also used in medical devices, gauges, and radiation therapy to treat cancer, while in some cases, it emerges as a waste product of nuclear reactors.According to the agency, exposure to low levels of Cesium-137 over time could pose a “potential health concern.” Trace amounts of the isotope are found globally in soil, air and food. While the levels detected in the shrimp were far below FDA intervention thresholds, officials said avoiding potentially contaminated products could help reduce unnecessary exposure to radiation.