Occupational ionizing radiation exposure among medical workers rose during the COVID-19 pandemic: a retrospective study

Every day, millions of people walk into hospitals and clinics to receive care that relies on invisible energy. Doctors use X-rays to see broken bones, CT scanners to map the inside of the body, and specialized procedures to guide tools through blood vessels without making large cuts. These tools use ionizing radiation, a form of energy powerful enough to pass through tissue and create images or treat disease. While this technology saves lives, it also means that the people who operate it—the radiologists, technicians, and nurses—are the largest group of workers exposed to artificial radiation in the world. Over many years, even small amounts of this exposure can add up, potentially affecting the thyroid, the eyes, or the blood. Because of this, health organizations set strict safety limits to ensure that no worker receives too much radiation in a single year or over a five-year period. The goal is always to keep exposure as low as reasonably possible while still providing the best care for patients.

When the COVID-19 pandemic struck in early 2020, the way hospitals operated changed dramatically. For three years, lockdowns and isolation measures reshaped medical practice, and doctors found themselves performing more lung scans and imaging tests to diagnose the virus. This shift raised a quiet but important question: did the extra work and the stress of the pandemic lead to higher radiation doses for the medical staff wearing the badges that track their exposure? A team of researchers at the Second Affiliated Hospital of Chongqing Medical University set out to answer this by looking at a vast collection of records spanning from 2008 to 2024. They wanted to see if the pandemic changed the long-term patterns of radiation exposure for their workers and to identify which types of jobs or personal characteristics made a worker more likely to receive a higher dose.

The researchers gathered data on more than 500 medical workers, tracking nearly 3,700 individual yearly records. Each worker wore a small personal monitor, similar to a badge, that measured the radiation they received while on duty. These badges were swapped out every three months, and the data was checked by an independent lab to ensure accuracy. The team looked at the numbers to see who was getting the most exposure. They found that, on average, men received slightly higher doses than women, and workers between the ages of 40 and 50 tended to have higher exposure than younger or older colleagues. Those with doctoral degrees and those working in interventional medicine—a field where doctors use imaging to guide procedures inside the body—also saw higher levels. When looking at specific departments, the interventional medicine team had the highest average annual dose, followed closely by cardiology and surgery.

The study then turned its attention to the timeline, comparing the years before the pandemic, the three years of the outbreak, and the years immediately after. The long-term trend from 2008 to 2024 showed that for most groups, radiation exposure remained relatively stable, with no dramatic rise or fall over the decades. However, when the researchers zoomed in on the pandemic years, a clear spike appeared. During the height of the outbreak, the average radiation dose for almost every group of workers increased significantly compared to the years before. This was true for men and women, for doctors and other staff, and for workers in nearly every department. The year 2021, in particular, stood out as having the highest exposure levels across most categories. This suggests that the surge in medical imaging needed to manage the virus, combined with the challenges of working in protective gear, led to more radiation reaching the staff.

Once the strict lockdown measures were lifted and the world began to return to normal, the radiation doses dropped sharply. The levels in the years following the pandemic were significantly lower than they were during the outbreak. This decline indicates that the medical workforce and the hospital systems adapted to the new reality, perhaps by streamlining procedures or returning to pre-pandemic workflows. Despite the spike during the crisis, the researchers noted that the vast majority of annual doses remained well below the safety limits set by international health authorities. Even at their highest point during the pandemic, the average worker was not receiving dangerous amounts of radiation.

The study also looked at what factors might predict who gets the most exposure. While the overall trends were clear, the specific risk factors shifted depending on how the data was grouped. For instance, being a doctor or working in interventional medicine consistently appeared as a factor for higher exposure. Interestingly, the pandemic itself acted as a risk factor for higher doses during the outbreak years, but once the crisis passed, the post-pandemic period became a protective factor, associated with lower doses. The researchers acknowledged that their study had limits, such as being based on data from a single hospital, which means the findings might not apply exactly to every medical center in the world. They also noted that they did not track the long-term health outcomes of the workers, only the radiation doses themselves.

Ultimately, this research provides a clear picture of how a global health emergency can temporarily alter the safety landscape for medical workers. It confirms that while the medical community is generally successful at keeping radiation exposure within safe limits, periods of high demand and crisis can lead to a measurable increase in the dose workers receive. The findings serve as a reminder that during public health emergencies, when the focus is intensely on patient care, the safety of the staff must remain a priority. By understanding these patterns, hospitals can better prepare for future crises, ensuring that the people who protect us from disease are also protected from the hidden risks of the tools they use every day.