Climate Change May Unearth Cold War-Era Nuclear Waste Stored by the U.S. in Other Countries

A new report finds that melting ice and rising sea levels could disturb radioactive contamination left over from American nuclear tests after World War II

a large, circular concrete container on the coast, surrounded by trees and beach
Runit Dome in the Marshall Islands contains radioactive waste from U.S. activity during the Cold War. A new report says climate change may cause its contaminants to enter the environment. U.S. Department of Energy

Rising global temperatures could unearth Cold War-era nuclear waste created by the United States and stored in other countries, posing potential issues for the environment and local inhabitants, according to a new report.

An assessment conducted by the U.S. Government Accountability Office (GAO) released earlier this year examined nuclear waste in the Marshall Islands, Greenland and Spain, three locations with radioactive contamination resulting from American nuclear activity in the decades following World War II. Climate change could cause this nuclear waste to enter the environment, as warming temperatures melt ice sheets that contain radioactive liquid and raise sea levels that could pollute food and water sources with toxic waste, per the study.

This lingering contamination came from nuclear weapon detonations, including hydrogen bombs, and accidents at numerous sites around the world. Often, the U.S. government stored this waste near the sites of detonation, Robert Hayes, a nuclear engineer at North Carolina State University, says to Julia Jacobo of ABC News. In Greenland, officials disposed of nuclear waste in the ice sheet, and in the Marshall Islands, they placed it in a container with a concrete cap.

“The military was in the rush of the Cold War,” Hayes tells the publication. “In hindsight, they could have done a better job.”

map with marshall islands, greenland and spain pointed out; images show weapons tests
A figure from the paper details the locations of radioactive contamination abroad from U.S. activities during the Cold War. GAO; Republic of the Marshall Islands: National Museum of Nuclear Science and History; Greenland: Bryan Ambrust / U.S. Army Corps of Engineers, Engineer Research and Development Center; Spain: National Museum of Nuclear Science and History; Map Resources

Weapons testing in the Marshall Islands

The Marshall Islands, a Pacific Ocean nation especially threatened by climate change, stands the greatest risk of impact from nuclear waste, according to the report.

As sea levels rise, groundwater underneath Runit Dome, a concrete structure built to enclose the radioactive waste in the country, may well up due to large-scale flooding, which could lead to leaks in radiation. A storm surge may also spread that radiation throughout the islands, amplifying the impact of a leak.

Sixty-seven American nuclear weapons tests occurred in the Marshall Islands between 1946 and 1958, including Castle Bravo on Bikini Atoll, the largest-ever U.S. nuclear detonation. The blast was 1,000 times more powerful than the atomic bomb dropped on Hiroshima and caused a greater fallout than scientists predicted. Most of the testing was in preparation for the possibility of World War III, William Roy, who studies radioactive waste management at the University of Illinois Urbana-Champaign, tells ABC News.

Residents of the Marshall Islands have already felt the cost of living with radioactive waste: Several atolls remain uninhabitable, and radiation has resulted in cancer and other negative health consequences for Marshallese, as well as enormous disturbances to traditional food-gathering practices.

Nathan Anderson, a director at the GAO, tells Grist’s Anita Hofschneider that U.S. responsibility for the waste on the Marshall Islands is “defined by specific federal statutes and international agreements.”

“It is the long-standing position of the U.S. government that, pursuant to that agreement, the Republic of the Marshall Islands bears full responsibility for its lands, including those used for the nuclear testing program,” Anderson tells the publication.

a mushroom cloud after the detonation of a weapon test near Bikini Atoll
The "Baker Test" on July 25, 1946, detonated an atomic bomb off Bikini Atoll in the Marshall Islands. Digital Vision via Getty Images

The Department of Energy maintains that the risk to human health and the environment is low. But due to the lack of trust from Marshallese toward the information on the radiation provided by the U.S., the GAO report recommends more communication between the Department of Energy and the Marshallese government.

The Marshall Islands has been included in numerous studies of radiation exposure, including an investigation last year about how turtle shells can tell scientists about the impact of historical nuclear events on the environment.

Nuclear remains in Greenland ice

If greenhouse gas emissions continue at their current rate, the Greenland ice sheets that contain nuclear waste from Cold War testing could melt within the next 75 years. According to a 2016 study, this would “guarantee” the contaminants from the U.S. military research site Camp Century would be released into the environment.

Since Greenland is part of the Kingdom of Denmark, the European nation permanently monitors the melting of the ice sheet around Camp Century as a result of public concern incited by the 2016 study. They are also examining whether meltwater will allow the contaminants to leach out of the ice.

From their findings, Danish scientists have determined that the contaminants should remain frozen until 2100. The short-lived radioactive isotopes have already decayed, and the long-lived isotopes will have lost most of their radioactivity by the end of the century and will be diluted by melting ice. But other studies have found that carcinogenic chemicals called polychlorinated biphenyls (PCBs) from Camp Century might have a larger impact.

“The possibility to influence the environment is there, which could further affect the food chain and further affect the people living in the area as well,” Hjalmar Dahl, president of Inuit Circumpolar Council Greenland, tells Grist. “I think it is important that the Greenland and U.S. governments have to communicate on this worrying issue and prepare what to do about it.”

A plane crash over Spain

In Spain, a midair collision of two planes in 1966, one of which carried a hydrogen bomb, caused nuclear debris to contaminate the town of Palomares. While no weapons detonated as a result of the crash, two of the four that fell to the ground were damaged, releasing radioactive plutonium.

A 1990 assessment found that radiation levels in Palomares exceeded European Union standards, and in 2015, the U.S. and Spain agreed to remediate the area. The nations have not yet implemented any plans since then, though initial cleanup efforts involved removing contaminated soil from the area and transporting it to the U.S.

However, regarding nuclear radiation, “there is generally a public fear that is much higher than the actual risk,” Hayes tells ABC News. And in terms of climate change, its other effects, from extreme weather to food insecurity, will be more immediate and damaging, per the publication.

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