How Manhattan Project Waste Still Affects Health Today
The radioactive waste from the world's first atomic bombs remains with us, and scientists are still uncovering its health effects
Seventy-five years after the Manhattan Project produced the world's first atomic weapons, a hidden legacy persists in communities across the United States. While the dramatic mushroom clouds have long vanished, low-level radioactive waste from nuclear weapons production remains in the environment, creating ongoing health concerns that scientists continue to investigate. From the waters of Coldwater Creek in Missouri to the neighborhoods near former processing plants in New Jersey, epidemiological studies are uncovering the human health costs of the atomic age—stories that remained largely hidden for decades. This is the story of how science is helping us understand the complex relationship between low-level radiation exposure and human health, revealing connections that span generations.
Low-level radioactive waste includes materials contaminated during nuclear weapons production, from protective clothing to chemical byproducts.
Epidemiological studies face challenges including long latency periods for diseases and difficulty reconstructing historical exposures.
Low-level radioactive waste from the Manhattan Project includes materials that became contaminated with radioactive elements during nuclear weapons production. This encompasses everything from protective clothing and equipment to chemical byproducts from uranium and thorium processing.
Unlike high-level waste such as spent nuclear fuel, these materials contain smaller amounts of radioactive substances, but they can still pose health risks, particularly when improperly stored or disposed of in the environment.
The health effects of radiation depend on several factors: the type of radiation (alpha, beta, or gamma particles), the duration of exposure, and whether the exposure is external or internal through inhalation or ingestion of radioactive materials 3 . Internal exposure often poses greater risks because radioactive particles can become concentrated in specific organs—for example, radioactive iodine in the thyroid or strontium-90 in bones.
Epidemiology—the study of patterns and causes of disease in populations—provides the primary toolkit for investigating potential health effects from historical radiation exposure. Scientists use several approaches:
These methods face significant challenges, including the long latency period for many radiation-linked diseases (sometimes 20 years or more), population mobility, and the difficulty of reconstructing historical exposures decades after they occurred.
Inhalation of radioactive particles
Ingestion through drinking water
Consumption of contaminated food
In Wayne, New Jersey, a former Department of Energy thorium processing facility operated from 1941 to 1973, processing monazite sands to extract thorium for the Manhattan Project and later for nuclear weapons production 1 5 . For decades, most residents were unaware that the site had left a legacy of elevated radiation levels not just at the facility itself, but also along Sheffield Brook, where contamination had spread 1 .
By the early 1980s, radiological surveys by the New Jersey Department of Environmental Protection confirmed elevated radiation levels, prompting one of the first epidemiological studies to investigate potential health effects on the surrounding community 1 5 .
In 1984, researcher Lisa Fetterman Voyce conducted a groundbreaking study that would become a model for future community-based health investigations 1 5 . The study employed a cross-sectional design with these key components:
Operated: 1941-1973
Purpose: Thorium extraction for Manhattan Project
Contamination: Sheffield Brook and surrounding area
Study Year: 1984
The analysis revealed several concerning patterns, though researchers noted the small sample size limited statistical significance 1 . The key findings included:
| Health Outcome | Finding | Statistical Significance |
|---|---|---|
| Overall cancer rates | No significant increase | Not significant |
| Liver disease (non-cancer) | More prevalent in all case groups | Notable but not significant |
| Birth defects | Greater for those living closer to site | Notable but not significant |
| Leukemia | Increased rate | Notable but not significant |
| Jaundice | Higher reported rate | Notable but not significant |
The study concluded that while no health effects reached statistical significance—meaning the findings could potentially be due to chance—there was an "aggregation of disease incidence" in the study area that merited further investigation 1 . This nuanced conclusion illustrates a common challenge in environmental epidemiology: detecting clear signals from weak or mixed exposures often requires larger studies than initially possible.
In July 2024, a powerful new study published in JAMA Network Open provided some of the strongest evidence yet linking Manhattan Project-era contamination to increased cancer risk 8 . The Harvard-led research investigated health outcomes among people who lived near Coldwater Creek in Missouri, where Mallinckrodt Chemical Works had improperly stored radioactive waste in open steel drums from the 1940s through the 1960s.
The study employed an innovative approach by using data from the St. Louis Baby Tooth Survey—a 1950s project that collected baby teeth from thousands of area children to study radioactive fallout. The researchers had access to addresses of 4,209 tooth donors born between 1945 and 1966, allowing them to precisely map childhood proximity to the contaminated creek 8 .
The findings were dramatic: people who lived within one kilometer of Coldwater Creek as children were 44% more likely to develop cancer over their lifetimes compared to those who lived more than 20 kilometers away 8 . The effect was even more pronounced for radiosensitive cancers (those known to be caused by radiation), which showed an 85% increased risk.
Increased overall cancer risk for those living within 1 km of Coldwater Creek as children
Increased risk for radiosensitive cancers among those with childhood exposure
"We actually saw something quite dramatic, not only elevated risk of cancer, but one that increased steadily in a sort of dose-response manner the closer the childhood residents got to Coldwater Creek"
The Trinity test in New Mexico—the world's first atomic detonation—may have produced the earliest radiation victims, despite decades of official denial 6 . Recently uncovered data shows a sharp 38% increase in infant mortality in 1945 in New Mexico counties downwind from the explosion, compared to 1946 6 . The most striking spike occurred in September 1945, with infant mortality rates 56% higher than expected based on surrounding years.
The 21-kiloton explosion occurred atop a 100-foot tower, sucking hundreds of tons of irradiated soil and debris into the atmosphere and spreading radioactive fallout over thousands of square miles 6 . The Centers for Disease Control later concluded that "New Mexico residents were neither warned before the 1945 Trinity blast, informed of health hazards afterward, nor evacuated before, during, or after the test" 6 .
Trinity test conducted in New Mexico
Infant mortality rates spike 56% higher than expected
38% increase in infant mortality in downwind counties
CDC confirms lack of warning or protection for residents
Date: July 16, 1945
Yield: 21 kilotons
Height: 100-foot tower
Fallout: Thousands of square miles
Manhattan Project workers also faced radiation risks. A 42-year follow-up study of 26 plutonium workers at Los Alamos found that their health outcomes were generally similar to the general population, with a lower-than-expected death rate 9 . However, specific radiation-related health effects were observed, including one case of osteogenic sarcoma (bone cancer) in a worker with elevated plutonium deposition 9 .
Essential Research Methods in Radiation Epidemiology
| Research Method | Application in Radiation Studies | Strengths | Limitations |
|---|---|---|---|
| Geographical studies | Comparing disease rates in contaminated vs. clean areas | Can reveal community-level patterns | Prone to confounding factors |
| Cohort studies | Following exposed workers over decades | Can establish timing of exposure before disease | Expensive and time-consuming |
| Case-control studies | Comparing cancer patients with healthy controls | Efficient for rare diseases | Vulnerable to recall bias |
| Dose reconstruction | Estimating historical radiation exposures | Allows for exposure-response analysis | Often relies on imperfect historical data |
A key concept in epidemiology, statistical significance helps researchers determine whether observed patterns are likely due to chance or represent real effects. Many early studies of low-level radiation effects lacked sufficient statistical power to detect small but important health impacts.
Common limitations in radiation epidemiology include small sample sizes, difficulty reconstructing historical exposures, long latency periods for diseases, population mobility, and confounding factors (other variables that could explain observed associations).
The epidemiological investigation into the health effects of low-level radioactive waste from the Manhattan Project remains ongoing. From the early findings in Wayne, New Jersey, to the recent compelling evidence from Coldwater Creek, science continues to uncover the long-term health consequences of nuclear weapons production.
What makes this research particularly challenging—and ethically significant—is that many exposures were imposed without consent on unaware communities. As one researcher noted about the Trinity test downwinders, these were people for whom "the government had not acknowledged the risks or protected them" 6 2 .
While scientific debate continues about the precise health risks of low-level radiation, the pattern emerging from decades of research suggests that the atomic age left behind more than just historical artifacts—it left a legacy of health concerns that epidemiology continues to unravel. For communities living with this contamination, understanding the past remains crucial for protecting their future.