The radioactive fallout of Trinity Nuclear Tests reached as far as Canada

The study also found that the aftermath of Trinity significantly contributed to exposures in New Mexico, in neighboring states and reached 46 of the 48 contiguous United States and Mexico.

The researchers’ estimates have concluded that the radioactive fallout from Trinity reached as far as Crawford Lake in Canada.

America's nuke history from 1945-1962

The study notes that nuclear weapon testing began with Trinity in 1945 and led to unrestrained releases of radioactive materials in the environment. These materials, over time, were transported via wind into the atmosphere and have been significantly exposed to the human population.

“The deposition of these materials, including plutonium 239 and 240, is now considered a potential geological marker for the beginning of the Anthropocene Epoch,” said the researchers in the study.

Anthropocene Epoch, an unofficial unit of geologic time, is used to describe the most recent period in Earth’s history when human activity started to have a significant impact on the planet’s climate and ecosystems.

The study also took into account the other 100 nuclear weapon tests carried out from 1945 onwards. The study notes that ninety-four generated radioactive mushroom clouds among the 101 atmospheric nuclear weapon tests carried out in the US.

No compensation for radioactive exposure

Moreover, the people living close to the test sites are compensated for being exposed to radioactive materials and potential diseases. But even though the radiation from Trinity was significant, the people were never compensated, which they are liable to under the 1990 Radiation Exposure and Compensation Act (RECA).

“Despite the Trinity test taking place in New Mexico, many New Mexicans were left out of the original RECA legislation, and nobody has ever been able to explain why,” said Senator Ben Ray Luján, a New Mexico Democrat, to The New York Times.

“Aggregated by counties and federally recognized tribal lands, our total deposition density estimates show that there are locations in New Mexico, and in other parts of the United States, including Utah, Nevada, Wyoming, Colorado, Arizona, and Idaho, where radionuclide deposition reached levels larger than those we estimate in some counties covered by RECA,” concluded the study.

Even though this study remains an important addition to understanding the repercussions of these catastrophic events, it’s important to note that the study is restricted to the limited public information available in government reports and the literature. The researchers have assumed that all tests were performed with plutonium-239, like in Trinity. The exact composition of each test device remains unknown.

Study abstract:

One hundred and one atmospheric nuclear weapon tests were conducted between 1945 and 1962 in the United States, resulting in widespread dispersion of radioactive fallout, and leading to environmental contamination and population exposures. Accurate assessment of the extent of fallout from nuclear weapon tests has been challenging in the United States and elsewhere, due to limited monitoring and data accessibility.

Here we address this deficit by combining US government data, high-resolution reanalyzed historical weather fields, and atmospheric transport modeling to reconstruct radionuclide deposition across the contiguous United States, 8 with 10-kilometer spatial and one-hour temporal resolution for five days following detonation, from all 94 atmospheric tests detonated in New Mexico and Nevada with fission yields sufficient to generate mushroom clouds. Our analysis also includes deposition estimates for 10 days following the detonation of Trinity, the first ever nuclear weapon test, on July 16, 1945.

We identify locations where radionuclide deposition significantly exceeded levels in areas covered by the US Radiation Exposure Compensation Act (RECA).9 These findings include deposition in all 48 contiguous US states. They provide an opportunity for re-evaluating the public health and environmental implications from atmospheric nuclear testing.

Finally, our findings also speak to debates about marking the beginning of the Anthropocene with nuclear weapons fallout.10,11 Our deposition estimates indicate that direct fallout from Trinity, a plutonium device, reached Crawford Lake in Canada, the proposed “golden spike” site marking the beginning of the Anthropocene epoch,12,13 starting on July 20, 1945.