Published on February 23 in Nature Communications, the study is the first in the 21st century to assess the relationship between proximity to nuclear power plants and cancer mortality across all U.S. counties and every operational NPP in the country. While the researchers cautioned that their findings do not establish a cause-and-effect relationship, they said the results underscore the need for deeper investigation into the potential health impacts of nuclear energy.

Previous research from around the world examining possible links between nuclear power plants and cancer has produced mixed conclusions. In the United States, such studies have been limited in number and scope, often focusing on individual plants and nearby communities.

To broaden the evidence base, the researchers conducted a national-level analysis of cancer mortality between 2000 and 2018 using what they described as a “continuous proximity” approach. Instead of examining the effect of a single plant, the model assessed the cumulative impact of all nuclear power plants located near a county.

Data on plant locations and operational timelines—including some facilities in Canada—were obtained from the U.S. Energy Information Administration. County-level cancer mortality data were sourced from the Centers for Disease Control and Prevention.

The analysis accounted for a range of potential confounding factors, including median household income, educational attainment, racial composition, smoking prevalence, body mass index, temperature, humidity, and access to healthcare, such as distance to the nearest hospital.

The findings indicate that counties situated closer to nuclear power plants experienced higher cancer mortality rates even after adjusting for socioeconomic, environmental, and healthcare-related variables. The researchers estimate that between 2000 and 2018, approximately 115,000 cancer deaths nationwide—about 6,400 annually—were attributable to proximity to NPPs. The association appeared most pronounced among older adults.

“Our study suggests that living near a NPP may carry a measurable cancer risk—one that lessens with distance,” said senior author Petros Koutrakis, Akira Yamaguchi Professor of Environmental Health and Human Habitation. “We recommend that more studies be done that address the issue of NPPs and health impacts, particularly at a time when nuclear power is being promoted as a clean solution to climate change.”

The team noted that their findings align with results from an earlier Massachusetts-based study, which reported elevated cancer incidence among communities living nearer to nuclear facilities.

However, the researchers acknowledged certain limitations. The study did not include direct radiation exposure measurements and assumed equal impact from all nuclear power plants, which may affect the precision of the estimates.

They emphasised that further research, incorporating more detailed exposure data, is needed to clarify the nature and mechanisms of the observed association.

More evidence

A global meta-analysis in 2024  has found elevated risks of certain cancers among workers and residents exposed to radiation levels from nuclear power plants that fall within current international safety limits, raising fresh questions about long-standing regulatory standards.

The study, titled “Health Effects of Occupational and Environmental Exposures to Nuclear Power Plants: A Meta-Analysis and Meta-Regression”, was published in June 2024 in Current Environmental Health Reports.

The authors write: “Numerous epidemiological studies have shown increased health risks among workers and residents living near nuclear power plants exposed to radiation levels meeting regulatory dose limits.” They add that the aim was to evaluate disease risks “among these populations exposed to radiation levels meeting the current regulatory dose limits.”

The research team reviewed 47 studies from 17 countries, covering 175 nuclear power plants and involving 480,623 workers and more than 7.5 million residents. Using random-effects meta-analysis and meta-regression models, they assessed cancer and non-cancer risks linked to occupational and environmental radiation exposure.

Among workers, the findings were mixed. The study reports that “Workers had a significantly lower risk for all-cancer and a significantly higher risk for mesothelioma.” In contrast, residents living near nuclear facilities showed consistently elevated risks. According to the paper, “Residents had significantly higher risks for all-cancer, thyroid cancer, and leukemia.”

Particularly concerning were findings for young children. The authors note: “Notably, children under 5 years old showed the highest risk for all-cancer.”

The study also identified a dose-response pattern in non-cancer outcomes. The researchers state: “Our meta-regression showed a significantly positive dose-response relationship between cumulative dose of radiation exposure and risk for circulatory disease among workers.”

Current radiation safety standards are largely based on recommendations from the International Commission on Radiological Protection (ICRP), which in 1990 set regulatory dose limits at 100 millisieverts (mSv) per five years for workers and 1 mSv per year for the general public. These limits remain in force today.

However, the authors caution that there is still scientific uncertainty. They point out that regulatory limits are “based solely on the risk of cancer and heritable effects,” while “uncertainty also remains regarding the dose-response and dose threshold of non-cancer diseases at low doses of radiation exposure.”

In their summary, the researchers conclude: “Our findings demonstrated higher risks for mesothelioma for workers and all-cancer, thyroid cancer, and leukemia for residents exposed to low-dose radiation from nuclear power plants.” At the same time, they warn that “Some included studies did not adjust for cancer risk confounders, which could overestimate the association between radiation exposure and cancer risk and increase the risk of bias.”

The authors say the findings underscore the need to reassess whether radiation exposure within existing regulatory limits is fully protective against both cancer and non-cancer diseases.

Expert speak

Dr Gaurav Jaswal, Director and Consultant Radiation Oncologist at TGH-Onco Life Cancer Centre, Maharashtra, said the study highlights an association at the population level but does not establish causation.

Referring to the study, he said its conclusions are drawn from statistical models rather than direct radiation dose measurements. “Such studies are useful as a starting point for further research, but they should be taken with a pinch of salt. They should not be used to create unnecessary fear among people living near nuclear facilities,” he said.

Addressing concerns about long-term, low-dose exposure, Dr Jaswal said the debate often revolves around the “linear no-threshold model,” which assumes that any amount of radiation, however small, carries some cancer risk. However, he emphasised that the study itself acknowledged possible confounding factors such as local industrial exposure, socioeconomic status, and lifestyle influences. “Scientifically, we cannot draw a clear causal relationship based on this data alone. The risks discussed are probabilistic, not absolute,” he said, adding that the actual exposure levels around safely operating plants remain well within permissible limits.

He also clarified that while children, pregnant women, and the elderly are generally more sensitive to radiation, this does not mean that merely living near a properly regulated and safely run nuclear plant automatically increases their cancer risk. “If there is no significant increase in radiation exposure beyond background levels, there is no evidence to suggest a definite added risk,” he said.

On screening, Dr Jaswal advised against panic-driven measures. He recommended that residents near nuclear plants follow standard cancer screening guidelines applicable to the general population. These include routine health check-ups, colon cancer screening beginning around 45–50 years of age, low-dose CT scans for individuals with a significant smoking history, and PSA testing for older men where appropriate. “There is no need for additional or extraordinary screening solely on the basis of this study,” he said.