SEOUL, South Korea, Dec. 26 (UPI) -- Several North Korean defectors who lived near the North's main nuclear test site have shown symptoms of possible radiation exposure although it is hard to determine whether they were affected by nuclear tests, Seoul's Unification Ministry said Wednesday.

The ministry announced the results of a 54-day medical check-up and tests for radiation exposure on 30 former residents of Kilju County in Hamgyongbukdo Province. The area is home to the Pyunggyeri Nuclear Test Site where all six of North Korea's nuclear tests were conducted. All defectors who were screened had left the county after the North's first nuclear test in 2006 and arrived in the South before the fourth test in January last year.


Continuous reports of landslides and tunnel collapse following the North's sixth nuclear test in September has given rise to concern of possible radiation leaks. A number of defectors have recounted cases of sudden illnesses and birth defects believed to have been caused by radiation poisoning.

From October, the Korea Institute of Radiological and Medical Sciences ran urine tests, whole-body counting and chromosomal exams on the 30 defectors, according to E Daily.

While the urine test and whole-body counting didn't show significant abnormalities, the chromosomal test found that four examinees had breached the minimum detectable level of 0.25 Gy in radiation exposure. However, further testing showed readings below the acute dose of 0.1 Gy.

While the four "could be suspected of radiation exposure," the ministry said other factors may have affected their results such as age and smoking habits.

It said there are limitations to drawing conclusions on the recent check-up, as there hadn't been enough information or sufficient sampling numbers to pinpoint the cause of irregularities. Also, as a long time has passed since the examinees had left the North.

The ministry plans to continue testing defectors for radiation exposure, based on where they were living in the North and the timing of their defection, Yonhap reported.