For nearly 50 years, more than 200,000 barrels of radioactive waste have rested on the seafloor of the Atlantic Ocean. The containers, dumped by European nations during the Cold War, are now decaying and raising fears of contamination to marine life and seafood consumed by millions.
Cold War-Era Dumping
Between 1946 and 1990, countries including France and the United Kingdom disposed of radioactive waste in deep ocean trenches. The barrels, often sealed in asphalt or concrete, were dropped thousands of feet below the surface into the Bay of Biscay, about 400 miles off the French coast. This practice was later regulated by the Nuclear Energy Agency (NEA), an international body that now oversees nuclear safety and waste management.
In total, an estimated 42 petabecquerels of low-level radioactive waste were dumped into the North-East Atlantic. While much of it was low-strength material, researchers caution that some dangerous isotopes, including strontium-90 and caesium-137, may still pose risks to the marine food chain.
French Expedition Uncovers the Barrels
A team of French scientists from the National Centre for Scientific Research recently completed a four-week mission aboard the research vessel L’Atalante. Using sonar and the autonomous underwater robot UlyX, the team mapped sections of the Abyssal Plains and located 3,355 barrels so far. Photographs revealed many barrels intact, others corroded or deformed, and some leaking black material believed to be bitumen.
“Onboard radiation safety instruments detected values close to natural environmental background levels,” the team reported. However, they noted that laboratory analysis of collected water, sediment, and biological samples could take months to confirm the extent of radioactive leakage.
Risks to Marine Life and Humans
Scientists warn that radionuclides such as strontium-90 can mimic calcium, allowing them to be absorbed by fish and shellfish. Once inside the food chain, these contaminants could spread to humans. Long-term health risks include tissue damage, genetic mutations, and increased cancer rates. The barrels, originally designed to last only 20 to 26 years, are now decades past their expected durability.
The French expedition collected more than 1,300 gallons of water, 345 sediment cores, and 19 biological samples for testing. Researchers are also screening for PFAS chemicals, known as “forever chemicals,” which persist in the environment and are suspected carcinogens.
Next Steps and Global Concern
A second research mission is planned for next year to measure radionuclides in marine organisms and trace potential leaks. Experts stress that while the immediate radiation risk to humans is considered low, the long-term ecological impact could be severe if radioactive material continues to seep into the water.
The discovery underscores how past nuclear practices are now resurfacing as global environmental hazards. With barrels still scattered across the ocean floor, scientists warn that the true impact may not be felt for decades but could affect future generations worldwide.