Manhattan Project: Radioactive Fallout From First Nuclear Test 'Trinity' Reached 46 US States, Canada And New Mexico, Study Says

The study has described the impact of nuclear explosions, including Trinity, carried out in New Mexico and Nevada between 1945 and 1962, and how the fallout led to widespread radioactive contamination

Oppenheimer: The Manhattan Project, led by American physicist J Robert Oppenheimer, gave the world its first nuclear weapons. The first nuclear test was conducted on July 16, 1945, at the Alamogordo Bombing Range, also known as the Jornada del Muerto, located in New Mexico. As part of this field test, the first atomic bomb was exploded, and Oppenheimer called the test "Trinity" in reference to one of John Donne's Holy Sonnets. A plutonium implosion device known as "Gadget" was used. About eight decades after the first nuclear weapon test was conducted, a new study found that the radioactive fallout from Trinity not only resulted in significant nuclear exposure in New Mexico, but also reached 46 neighbouring states in the US, and also Canada and Mexico. 

The pre-print of the study appeared around the same time as the release of Christopher Nolan's latest movie, Oppenheimer, which documents the triumph and tragedy of the physicist, widely regarded as the "Father of the Atomic Bomb". The study has also described the impact of other nuclear explosions carried out in New Mexico and Nevada between 1945 and 1962, and how the fallout led to widespread radioactive contamination. Radioactive materials from these nuclear explosions were also deposited in regions such as Utah, Colorado, Idaho, Wyoming, Arizona and numerous federally recognised tribal areas. 

The study, led by the Program on Science and Global Security (SGS), Princeton University, has documented a total of 94 US atmospheric nuclear weapon tests. A total of 101 atmospheric nuclear weapon tests were conducted between 1945 and 1962 in the US. These explosions resulted in radionuclide deposition that led to environmental contamination and population exposures. 

As part of the study, researchers led by Sébastien Philippe of SGS have estimated the deposition of radioactivity over 10 days after the detonation of the Trinity atomic bomb, and for five days following the atmospheric tests in Nevada. The estimates suggest that significant radioactive contamination occurred in regions in New Mexico and on federally recognised tribal lands not covered by the US Radiation Exposure Compensation Act. Plutonium carried by wind from the location of the Trinity test reached Crawford Lake in Canada on July 20, 1945, the study found. 

According to the study, the presence of plutonium in Crawford Lake sediments has been proposed as a marker for the beginning of the Anthropocene epoch. This is the proposed "golden spike" that marks the beginning of the Anthropocene epoch.

More about the Manhattan Project

As part of the Manhattan Project, Oppenheimer’s research team bombarded neutrons with plutonium or uranium-23 to initiate a nuclear fission reaction, during which the heavy plutonium or uranium nucleus split into smaller nuclei, and released huge amounts of energy and other neutrons. These neutrons, in turn, hit other nuclei and caused them to split, releasing more energy and neutrons in the process. This is a chain reaction, which, if left unchecked, can create an atomic bomb.

On August 6, 1945, almost a month after the Trinity test, the untested uranium-235 gun assembly bomb, known as the Little Boy, was dropped on the Japanese city of Hiroshima. This was the first atomic bomb used in war. The bomb instantly killed 70,000 people, and due to the effects of radiation, over 100,000 people subsequently died.

On August 9, 1945, a replica of the plutonium-239 implosion device tested in Trinity, was dropped on Nagasaki. This bomb was called Fat Man.

This bomb instantly killed about 40,000 people, and at least 30,000 more died due to injuries and radiation poisoning by the end of the year.

The next day, the Japanese initiated surrender negotiations. Meanwhile, Groves had informed US President Harry S Truman that another bomb would be ready for delivery within a week. In Oppenheimer, Gary Oldman plays President Truman.

On September 2, 1945, Japan formally announced its surrender on board the USS Missouri.

After the hostilities came to an end, Manhattan Project physicist Philip Morrison travelled to Hiroshima to study the aftermath of the nuclear explosion, but he was so devastated by what he witnessed, that he spent the rest of his life campaigning against nuclear weapons.

The Manhattan Project marked the true beginning of the Atomic Age. As part of the three-year project, scientists made several important discoveries associated with bomb mechanics, atomic particles, nuclear fission, and also obtained insights into nuclear fusion. Most importantly, it brought together a large number of scientists and leaders together, who put their heart and soul into making the Manhattan Project a quintessence of scientific triumph.

The Manhattan Project was followed by Operation Crossroads, as part of which two peacetime atomic weapons tests were performed.

After this, the Manhattan Project came under the jurisdiction of the US Atomic Energy Commission (AEC).