Prolonged exposure to low-dose radiation elevates risk of hypertension

Long-term exposure to low doses of ionizing radiation raises a person’s risk for developing high blood pressure, according to a Hypertension study of more than 22,000 nuclear facility workers in Russia.

The study, spearheaded by Tamara Azizova, MD, and published May 3, looked at the incidence of hypertension in a group of employees at Mayak Production Association, Russia’s first large-scale nuclear enterprise. The workers were hired between 1948 and 1982 and had been on the job for an average of 18 years, consistently exposed to low levels of ionizing radiation.

Upon analyzing the workers’ health records up to 2013, Azizova and her team found 38% of the population—8,400 employees in total—had hypertension, defined as 140/90 mmHg and up. That’s a higher incidence of hypertension than among Japanese survivors after the Hiroshima atomic bombing, but a lower incidence than the estimated risk among clean-up workers after the Chernobyl nuclear accident in Ukraine.

Azizova said in a release the differences in prevalence seem to correlate with workers’ amount of radiation exposure—Hiroshima survivors were exposed to a strong, singular blast, while Chernobyl workers were exposed to radiation for longer periods of time. Employees at the Mayak facility were exposed to low doses for even longer, with half having worked there for at least 10 years.

“It is necessary to inform the public that not only high doses of radiation, but low to moderate doses also increase the risk of hypertension and other circulatory system diseases, which today contribute significantly to death and disability,” Azizova said. “As a result, all radiological protection principles and dose limits should be strictly followed for workers and the general public.”

She said the number of people exposed to low-dose radiation has increased in recent years, especially with the growing popularity of imaging modalities like computed tomography. But while researchers tend to emphasize the oncological risks of radiation, other health risks exist, too.

“We believe that an estimate of the detrimental health consequences of radiation exposure should also include non-cancer health outcomes,” Azizova said. “We now have evidence suggesting that radiation exposure may also lead to increased risks of hypertension, cardiovascular disease and cerebrovascular disease, as well.”