by Mona Jhaveri - May 30, 2022

The first-ever nuclear weapon on Earth was detonated on July 16, 1945. Before this moment in World War II, little to no attention had been given to the potential risks of nuclear radiation. Unfortunately, that all changed in an instant. The first atomic test unleashed a new era of fear and destruction and increased cancer risk worldwide.

Scientists have established a direct link between increased cancer risk and radioactive fallout from a nearby nuclear explosion by investigating the aftermath of nuclear detonations in Hiroshima and Nagasaki.

But what about open-air nuclear weapons testing? Surely the amount of radiation released into the atmosphere during these tests is much less than that of a nuclear explosion?

This blog post will explore the risks of cancer associated with open-air nuclear weapons testing and how radiation from these tests can spread around the world.

Open-air nuclear weapons testing, a history

Since the first nuclear test in 1945, more than 500 nuclear weapons tests have been conducted worldwide. Most of these tests have been performed by just five countries: the United States, the Soviet Union, the United Kingdom, France, and China.

Above-ground nuclear weapons testing took place from 1945 to 1980. The most intense testing period happened until 1963, when the Limited Test Ban Treaty was signed. Nevertheless, countries like France and China, which did not sign the Treaty, continued testing their nuclear bombs until 1980.

In total, 504 nuclear devices were exploded at 13 testing sites. Since 1980, India and Pakistan have performed a number of above-ground nuclear weapons tests in 1998. Most recently, North Korea tested two nuclear devices in 2006 and 2017.

The effects of open-air nuclear weapons testing

When a nuclear bomb detonates, a large, destructive fireball is released. This fireball incorporates (and vaporizes) everything in its path, including soil and water. It expands until it starts cooling down and losing its buoyancy. However, ionized radioactive particles, dirt, and other debris created by the fireball are lofted into the atmosphere in the shape of the well-known mushroom cloud.

These radioactive particles then travel many miles from the detonation site, depending on weather conditions, wind speeds, and directions. Large radioactive particles tend to settle locally (anywhere between 30-300 miles from “ground zero”), but small ones can travel the world.

Even though nuclear testing sites are extremely remote and not within at least 60 miles of the human population, the CDC estimates that any person (and being) living in the United States in 1951 was exposed to some radiation fallout from nuclear testing.

Exposure to this form of radiation comes from several different sources:

  • Air – by breathing in radioactive material and from direct skin contact with radioactive material in the air
  • Food – by consuming milk, meat, or plants that had radioactive material in them
  • Ground – from fallout particles that fell on the ground and later came into contact with skin

Cancer and open-air nuclear weapons testing

Out of all known human carcinogens (substances that cause cancer), ionizing radiation is one of the most well-researched and well-understood. Over the decades, many studies have been conducted to investigate the relationship between ionizing radiation and different types of cancer.

The International Agency for Research on Cancer (IARC), part of the World Health Organization, has classified ionizing radiation as a Group 1 carcinogen – meaning that it is unequivocally carcinogenic to humans. This classification is based on the epidemiological evidence that exposure to ionizing radiation causes leukemia, thyroid cancer, and cancers of the breast, lung, stomach, ovary, bladder, and pancreas.

The largest source of ionizing radiation in humans is natural background radiation, which comes from the sun, outer space, and the Earth itself. The second-largest source is medical exposure from radiopharmaceuticals and X-rays. Finally, the third-largest source is exposure from atmospheric nuclear weapons testing.

There is no safe level of exposure to ionizing radiation, and any amount can increase cancer risk.

Let’s look at some specifics related to the Nevada Test Site.

Nevada Test Site data

The Nevada Test Site (NTS) was used for nuclear weapons testing from 1951 to 1962. During that time, 86 tests were performed above ground and another 14 underground tests that resulted in the significant atmospheric release of radioactive material.

In 1997, the National Cancer Institute (NCI) conducted a study to determine whether an increased cancer risk in the United States could be directly tied to NTS and global fallout from nuclear testing sites. The findings were as follows:

  • An estimated 49,000 cases of thyroid cancer might occur in the U.S. due to exposure to radioactive iodine released during nuclear weapons tests in Nevada. All of these persons were under the age of 20 between 1951 and 1957.
  • The number of leukemia deaths (not cases) attributed to radiation exposure from Nevada nuclear tests is projected to be about 1,800. This is approximately 0.12% of the total number of leukemia deaths expected eventually from the 1952 population of the United States.
  • Finally, about 22,000 solid cancers other than thyroid cancer and leukemia might be related to radiation exposure from Nevada nuclear tests and global nuclear fallout. Half of these are expected to be fatal.

These findings are in line with other studies that have looked at the cancer risk of nuclear weapons testing. For example, a study done on Marshall Islanders who were exposed to extremely high levels of radiation from atomic weapons tests showed an increased risk of developing thyroid cancer, leukemia, and other cancers of the blood and lymph system.

The numbers listed above are predictions and projections because it takes many years, even decades, for the full effects of relatively low doses of ionizing radiation to be seen and for the cancers to develop.

What does all this mean for the average person?

When investigating levels of radiation in a specific environment, it is usually very difficult to determine what the “background” level is. This is because there are many sources of ionizing radiation, both natural and manufactured, that can contribute to an area’s overall level of radiation.

The global average background dose of ionizing radiation is about 3.01 mSv per year. For context, a routine chest X-ray delivers about 0.1 mSv of radiation, and a flight from one coast to another in the United States exposes a person to about 0.035 mSv of radiation.

So, what does all this mean for the average person? In short, it isn’t easy to say. The cancer risk associated with exposure to ionizing radiation is dose-dependent, meaning that the more radiation someone is exposed to, the greater their risk of developing cancer. Therefore, it is difficult to make general statements about the cancer risk of exposure to radiation.

That being said, it is clear that there is an increased cancer risk associated with exposure to ionizing radiation, especially at higher doses. And as we have seen from the data above, nuclear weapons testing has resulted in significant releases of radiation into the environment, which has undoubtedly contributed to increased levels of radiation exposure for many people worldwide.

Those living downwind from nuclear test sites, such as in the Marshall Islands and the state of Nevada, are most at risk for health effects from radiation exposure. However, everyone is exposed to some level of radiation from nuclear testing and other sources.

Research like this is important to help us understand the long-term health effects of radiation exposure. To contribute to studies such as these and cancer research in general, visit our page of active campaigns. Donate today to help support the search for a cure.

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