Radioactive Time Bomb in the Atlantic: 200,000 Toxic Barrels Threaten Millions

The Legacy of Radioactive Waste in the Atlantic Ocean

For nearly half a century, more than 200,000 barrels containing radioactive waste have remained scattered across the Atlantic Ocean. These barrels are remnants of a time when it was believed that disposing of nuclear materials at sea was a safe practice. Between 1946 and 1990, European countries such as France and the UK engaged in this process, sealing the waste in asphalt and concrete. Today, these barrels lie thousands of feet beneath the ocean surface, resting in trenches that are approximately 13,000 feet deep and hundreds of miles off the French coast.

Scientists have raised concerns about the potential impact of these barrels on marine life and human health. There is a risk that radioactive materials could enter the marine food chain, be absorbed by sea creatures, and eventually reach seafood consumed by millions of people. This could lead to long-term health risks, including tissue damage and increased cancer rates.

A team of French scientists has recently located 3,355 of these barrels during the first of two planned missions to investigate their fate. Using advanced technology such as sonar and an autonomous underwater robot named UlyX, the researchers mapped the Abyssal Plains, which are roughly 400 miles off the French coast. A second mission, scheduled for next year, will involve measuring radionuclides in water, sediments, and marine organisms collected from the site. Researchers will also analyze background radiation to differentiate contamination from the barrels from other sources, such as nuclear accidents or authorized effluents from power plants.

The practice of dumping nuclear waste at sea was initially carried out under national supervision. Later, it came under international control through the Nuclear Energy Agency (NEA), an intergovernmental body comprising 34 member countries, including the United States. The NEA coordinates efforts related to nuclear safety, technology, and waste management. A test disposal under NEA supervision took place in 1967, and regulations were introduced for different types of waste containers to improve handling safety. A designated area in the outer Bay of Biscay became the primary disposal site.

Over a span of roughly 15 years, European nations disposed of approximately 42 petabecquerels of low-level radioactive waste into the North-East Atlantic. While this amount sounds significant—equivalent to 42 quadrillion atomic decays every second—it is spread across thousands of barrels on the ocean floor. Experts suggest that the deep-water location and the relatively weak radioactivity of much of the material mean the immediate risk to humans is low. However, long-term effects on marine life and the food chain remain a concern.

Approximately one-third of the dumped material was tritium, a weak form of radiation considered insignificant. The rest consisted mainly of beta and gamma emitters, which lose radioactivity over time, while about two percent was alpha radiation. Disposal at such depths was seen as safer than shallow-water dumping. Although containers were designed to slow the release of radioactive material, they were not intended to prevent it entirely, allowing short-lived components to decay over several years.

The submerged barrels have a lifespan of 20 to 26 years and are now well past their expected durability. Despite most containing low- or medium-level radioactive waste rather than the most dangerous materials, researchers caution that they still pose a potential long-term risk. Some radionuclides, like strontium-90, can mimic calcium and be absorbed by marine organisms, potentially moving up the food chain.

Radionuclides are unstable elements that emit radiation as they decay, with half-lives ranging from years to billions of years. For example, caesium-137 lasts about 30 years, plutonium-241 roughly 13 years, and uranium-238 around 4.5 billion years. This means some remain radioactive and potentially harmful for generations.

The research team, led by the French National Centre for Scientific Research, embarked on a four-week expedition aboard the research vessel L'Atalante in mid-June. UlyX, a 15-foot autonomous underwater vehicle, mapped the seafloor and captured images of barrels from as close as 30 feet. So far, approximately 50 barrels have been visually documented. Some remain intact, while others show signs of corrosion or deformation. Many are colonized by sessile organisms such as sea anemones.

In some instances, leaks of unknown substances, likely bitumen, were observed. Bitumen is a black, sticky mixture of hydrocarbons, either naturally occurring or a residue from petroleum processing. The team also deployed traps to collect fish and amphipods for radioactive analysis. Water samples were gathered at multiple depths, from the surface down to 15,430 feet above the seafloor. In total, the expedition collected 1,321 gallons of water, 345 sediment cores, and 19 biological samples.

Onboard radiation safety instruments detected values close to natural environmental background levels, according to the team's blog post. However, precise laboratory analyses of sediments, water, and fish samples will require several months. Beyond radioactive measurements, the team is also testing for PFAS, industrial chemicals that persist in the environment and are suspected carcinogens.