Source of carcinogenic, reactor-borne cesium-137 under investigation

By John LaForge

In a story unprecedented in Nukewatch Quarterly memory, multiple cargo containers carrying shrimp from Indonesia to U.S. grocers were found contaminated with dangerously radioactive
cesium-137 (Cs-137)

None of the dozens of reports reviewed by Nukewatch explained how the cancer-causing isotope Cs-137⸺ a human-made radionuclide only produced inside nuclear reactors ⸺ spread to multiple cargo containers.

U.S. Customs and Border Protection (CBP) alerted the Food and Drug Administration (FDA) August 19 about the contamination of the containers and shrimp products processed in Indonesia. The tainted containers and shrimp were found at the U.S. ports of Los Angeles, Houston, Miami, and Savannah (Georgia), and delivered to Walmart and Kroger stores.

The cesium scare has expanded broadly. The FDA’s August 19 Import Alert and recall recommendation focused on frozen raw shrimp, but the FDA later added cocktail shrimp and cooked medium peeled tail-off shrimp to its list of at-risk products. Initially applied to 13 states, the FDA later expanded its recall recommendation to 29 states.

Radioactively Contaminated Shrimp

The Wall St. Journal reported August 29 that the recall included 26,460 packages of Great Value cocktail shrimp sold at Walmart stores between July 28 and August 16, and 18,000 bags of Kroger’s Mercado frozen cooked shrimp.

California-based Southwind Foods recalled frozen shrimp bagged and sold under the brands Sand Bar, Arctic Shores, Best Yet, Great American Seafood Imports, and First Street, or Walmart’s Great Value brand.

Tens of thousands of packages of imported shrimp sold at Mariano’s were also recalled. Other affected stores include AquaStar, Baker’s, Gerbes, Jay C, Metro Market, Pay Less Supermarkets, Pick ‘n Save and Beaver Street Fisheries, according to the FDA, which told consumers to dispose of shrimp purchased at specific times in July and August. “If you have recently purchased raw frozen shrimp from Walmart that matches this description, throw it away,” the FDA said in a statement. The FDA did not recommend any special disposal system for radioactively contaminated material.

The FDA notification said, “All containers and product testing positive or alerting for Cs-137 have been denied entry into the country.” Neither the FDA nor the CBP have reported how many containers were found to be contaminated.

All the recalled shrimp came from Indonesia’s giant seafood processor PT Bahari Makmur Sejati, doing business as BMS Foods. The FDA has now targeted the firm with a new “import alert” to stop all its products from coming into the U.S.

The potentially hot shrimp was available from July 17 to August 8, 2025, at dozens of stores in Alabama, Alaska, Arkansas, Arizona, California, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Michigan, Minnesota, Missouri, Mississippi, Nebraska, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, and Wisconsin.

Is the cesium permitted in U.S. food safe?

The legally permitted level of Cs-137 contamination in U.S. food is 1,200 Becquerels per-kilogram (Bq/kg) ⸺ even for children. Japan’s permitted level for children is 50 Bq/kg, and 100 Bq/kg for adults. A Becquerel is a standard measure of radioactive decay.

In the United States, the same level of cesium contamination in food is allowed for women, girls, and infants, in spite of the well-established fact that they are far more vulnerable to radiation harm than men and boys.

Radiation and health expert Cindy Folkers of Beyond Nuclear in Tacoma Park, Maryland, reported in 2013 that, “As cesium passes out of your body, its radioactivity starts to damage your kidneys and your bladder, which in turn damages your body’s ability to rid itself of the cesium.” Folkers also noted that Cs-137 and Cs-134 do not occur in nature but are only created in nuclear reactors operated by the military, by industry, and by university researchers.

The FDA’s Import Alert warned about the Cs-137:

[R]adionuclides such as Cs-137, a radioisotope of cesium, can be present in many places around the world as a result of contamination produced high in the atmosphere during nuclear testing. Cs-137 is created via nuclear reactions, such as occurring in nuclear power plants and is also commonly used in medical and other industrial applications. Elevated amounts of Cs-137 can be present at locations where contamination settled from accidents such as Chernobyl in 1986 and Fukushima in 2011.

The Import Alert also described the health risks created by exposure to low doses of Cs-137:

Cs-137 emits beta particles and gamma radiation that are associated with adverse health effects. Potential for health concerns following Cs-137 exposure depends on the dose and the duration of exposure. High doses lead to acute radiation syndrome. However, exposure to low doses spread out over a period of time may not cause immediate apparent adverse effects but may still be harmful. The primary health effect of concern following longer term, repeated low dose exposure (e.g., through consumption of contaminated food or water over time) is cancer, resulting from damage to DNA within living cells of the body.

Where’d the cesium-137 come from?

Beyond Nuclear.org reported that the FDA is still investigating, “but contamination could be from nuclear industries in China, releases from the ruined Fukushima reactors, or somewhere else.”

Dr. Gordon Edwards, President of the Canadian Coalition for Nuclear Responsibility (CCNR), wrote September 10, 2025, “It is possible that the cesium-137 contamination came from a “food irradiation” plant, as the two radioactive substances most used in “irradiation” facilities are cobalt-60 and cesium-137.

Both cobalt-60 and cesium-137 are powerful gamma radiation emitters and are used to sterilize medical equipment, and to sterilize certain food items in “food irradiation” facilities. These plants use “very large quantities of cobalt-60 or cesium-137. Shrimp is one such food item,” Edwards wrote. For background on food irradiation see the CCNR website at https://ccnr.org/food_ccnr.html as well as https://ccnr.org/food_irradiation.html.

Kimberly Robertson, Program Director for the Fukushima Fallout Awareness Network, wrote August 26: “UK-based marine biologist Tim Deere-Jones stated, ‘Given the very low reported levels of Cs-137 in Indonesian marine environments, there is a strong possibility that the food fed to the [fish farmed] shrimp is the source of elevated cesium-137…. I consider it likely that such material, often harvested by ‘pirate fishers,’ could be contaminated with Fukushima-derived Cs-137, at endemically high levels in some Pacific Sea areas. It is strongly advised that the source/origin of the foodstuffs fed to the shrimps is investigated with the utmost rigor.’”

It is also possible that the contaminated shipping containers could have come into close contact with radioactive waste being shipped in the other containers on the same ship. It’s also possible, although highly unlikely and extremely scandalous, that the same containers used to ship the shrimp had earlier been used to transport radioactive waste.

Kimberly Robertson concluded her post urging: “Regardless of the exact source of the radioactive
contamination, [R.F.] Kennedy, as Secretary of the Dept. of Health and Human Services, must direct the FDA to lower the current allowable levels of cancer-causing Cs-137 in food. The shrimp radiation levels were detected at 68 Bq/kg, which would not have been allowed in Japan [due to its] 50 Bq/kg level for kids. U.S. kids, however, are allowed 1,200 Bq/kg, the same as adults. That must change.”

Sign and share the sign-on letter widely at https://nislappdc.org/wp-content/uploads/2025/05/FFAN-letter-to-HHS.pdf, and call the FDA at 1-888-SAFEFOOD to voice your concerns.