Cancer from Taking Scans? Koreans Frequently Request CTs, Is Radiation Safe? [News SeolCham]

(34) Radiation Exposure Just from Eating... Natural Radiation Not a Concern
Radon Bed Controversy... Caution Advised for Radiation Exposure from Household Products
South Koreans Undergo 7.7 Exams Annually, 7 Times Higher Than Advanced Countries
"Imaging Tests Needed but Safety Must Be Carefully Considered"

Editor's Note'Seolcham' is a newly coined term meaning to refer to detailed explanations. In [News Seolcham], we aim to pinpoint and explain in more detail the parts of the news that require fact-checking or further explanation.

It is known that Koreans undergo medical radiation examinations such as X-rays and computed tomography (CT) scans more frequently than people in other advanced countries, drawing attention to the appropriate levels of radiation exposure from medical devices. Exposure to high doses of radiation or repeated exposure to low doses below the standard level is known to cause diseases such as cancer or result in the birth of malformed babies. How cautious should we be about medical radiation exposure?

A scene of taking CBCT (Cone Beam Computed Tomography) at a dental clinic. The photo is for illustrative purposes and is not directly related to the article. [Image source=Getty Images]

The unit used when discussing radiation exposure issues is the 'Sv (Sievert)', which indicates the effect of radiation on the human body. The International Commission on Radiological Protection (ICRP) and domestic nuclear laws recommend an annual exposure limit of 1 mSv (millisievert, 1000 mSv = 1 Sv) for artificial radiation excluding natural radiation and medical radiation such as X-rays for the general public. The maximum allowable annual dose for nuclear power plant workers is 50 millisieverts. The effects of radiation on the human body include skin abnormalities, hair loss, cataracts, decreased white blood cells, infertility, and cancer, with the likelihood of occurrence increasing as the radiation dose increases.

Natural radiation is excluded from the recommended exposure standards because radiation exposure occurs when consuming food or breathing. Natural radioactive nuclides exist in the atmosphere, water, soil, rocks, and living organisms on Earth. According to the 2022 Nuclear Safety Yearbook by the Nuclear Safety and Security Commission, the average radiation dose from natural radiation sources for Koreans is 3.08 millisieverts, about 25% higher than the global average (2.4 millisieverts), due to the abundance of granite in Korea. Granite-type rocks release uranium through weathering processes.

Of course, the naturally occurring radiation dose is not harmful to health. However, it is important to note that radiation exposure can also occur through everyday products containing natural radioactive materials, such as mattresses and jewelry, as seen in controversies like the 'negative ion heating mat radiation detection' in 2007 and the 'radon mattress controversy' in 2018. The government has safety management regulations for processed products manufactured using radioactive nuclide-containing materials.

Frequent air travel also increases the risk of radiation exposure. Flying at high altitudes exposes passengers to more cosmic radiation from space. Flight attendants are subject to radiation exposure management by the Nuclear Safety and Security Commission (annual exposure limit of 6 millisieverts). According to the Radiation Information Service around Daily Life under the Korea Institute of Nuclear Safety, the radiation dose per one-way flight from Incheon Airport is ▲0.07 millisieverts to New York ▲0.05 millisieverts to London ▲0.03 millisieverts to Dubai ▲0.004 millisieverts to Tokyo. However, the amount of cosmic radiation reaching the Earth's surface can vary depending on solar activity.

Recently, the issue of 'radiation exposure from medical radiation' has become controversial. Although nuclear laws set recommended exposure limits, they do not specify appropriate standards for medical radiation. This is because medical radiation is used for patient diagnosis and treatment, and its benefits are considered to outweigh the risks. Nevertheless, regulations to minimize radiation exposure are also in place in the medical field.

The number of medical radiation examinations for Koreans is reportedly seven times higher than that of advanced countries. According to the Korea Disease Control and Prevention Agency's '2023 National Medical Radiation Usage Status,' the average Korean underwent 7.7 medical radiation examinations last year, compared to 1.1 in Switzerland and 0.5 in the European Union (EU). The per capita radiation dose for Koreans also shows an increasing trend: ▲2.46 millisieverts in 2020 ▲2.64 millisieverts in 2021 ▲2.75 millisieverts in 2022 ▲3.13 millisieverts in 2023.

Generally, a single comprehensive health check-up program exposes a person to about 2 to 3 millisieverts of radiation. According to the 2020-2022 National Medical Radiation Evaluation Report by the Korea Disease Control and Prevention Agency, the radiation dose per examination for adults is ▲0.38 millisieverts for breast cancer screening ▲0.01 millisieverts for bone density tests ▲1.8 to 2.4 millisieverts for head and neck CT ▲6.8 millisieverts for abdominal CT ▲4.0 millisieverts for chest CT ▲6.0 millisieverts for spinal CT ▲5.2 millisieverts for cerebral angiography CT.

Medical radiation examinations two to three times a year are considered safe. There is no need to avoid examinations when necessary, as X-rays and CT scans enable medical professionals to make accurate diagnoses. Radiation's cell-killing effect is also used for cancer diagnosis and treatment. However, excessive exposure to medical radiation can have negative effects, so the Korea Disease Control and Prevention Agency recommends careful consideration of examinations, taking into account the safety of medical radiation.