44% of Defectors from Near Punggye-ri Show Chromosomal Abnormalities... "Limitations in Directly Linking to Radiation Exposure"

Among North Korean defectors (defectors and persons of Northern origin) from areas near the Punggye-ri nuclear test site, 26 out of 59 people (44.1%) who underwent radiation exposure tests last year were found to have chromosomal abnormalities above the threshold, reflecting cumulative radiation exposure. However, it was determined that factors such as age, smoking, and medical radiation may have influenced these results, so it cannot be concluded solely from this data whether the radiation exposure was caused by North Korea's nuclear tests.

Photo shows Punggye-ri No. 4 tunnel before the explosion on May 25, 2018. Photo by Yonhap News.

On July 31, the Ministry of Unification released the results of the "2025 Survey on Radiation Exposure among Persons of Northern Origin," conducted by the Korea Institute of Radiological & Medical Sciences' National Radiation Emergency Medical Center. The survey targeted defectors from eight cities and counties near Punggye-ri (Kilju County, Hwaedae County, Kimchaek City, Myonggan County, Myongchon County, Orang County, Tanchon City, Baekam County), who fled North Korea after its first nuclear test in 2006.

Of the total 64 subjects, 59 underwent radiation exposure tests and general health check-ups. Five people who showed results above the threshold in radiation exposure tests between 2017 and 2024 received additional, detailed health examinations for follow-up.

According to the survey data, in the stable chromosomal aberration test—which reflects cumulative radiation exposure from birth to the time of testing—26 out of 59 people were found to have exceeded the minimum detectable limit of 0.25 gray (Gy).

An additional unstable chromosomal aberration test was conducted on these 26 individuals to determine whether they had been exposed to radiation within the most recent 3 to 6 months. Six individuals showed results above the minimum detectable limit of 0.1 Gy.

However, the institute interpreted the findings for these six individuals as being caused by recent factors such as medical radiation after entering South Korea, rather than exposure from North Korea's past nuclear tests. The institute also explained that the stable chromosomal aberration test could be influenced by various confounding factors, such as natural radiation, medical radiation, occupational exposure, age, smoking, drinking, and heavy metals.

Most participants who showed results above the threshold in the stable chromosomal aberration test were in their 50s to 80s, and some were confirmed to have a history of occupational exposure to hazardous substances, such as medical radiation and agricultural or heavy metal dust. The institute emphasized that there are limitations in directly linking these test results to radiation exposure from North Korea’s past nuclear tests.

Additionally, general health check-ups conducted on all 64 subjects found no cases of confirmed or suspected cancer. However, various findings were reported, including thyroid nodules, fatty liver, hyperlipidemia, and hepatitis B.

The institute stated, "Based on the current test results alone, it is not possible to determine the cause of exposure, the time of exposure, or the point influenced by confounding variables. Environmental information, such as ambient radiation doses, and measurements of radioactivity in water and food consumed while residing in North Korea, would be necessary for causal analysis, but there are limitations in obtaining such data."

Meanwhile, from 2023 to 2025, the government conducted radiation exposure tests on 174 defectors from the eight cities and counties near the Punggye-ri nuclear test site. Among them, 55 people (31.6%) showed results above the minimum detectable limit in the stable chromosomal aberration test.

This content was produced with the assistance of AI translation services.