Possible radiation exposure suspected among some N. Korea defectors

North Korea blows up Tunnel No. 4 at the North Korea's only known nuclear test site in Punggye-ri, North Hamgyong Province, May 24, 2018. Yonhap

Some North Korean defectors, who came from areas near the Punggye-ri nuclear test site in North Korea, showed signs of suspected radiation exposure, while it is hard to confirm that nuclear tests affected them, the unification ministry said Thursday.

The ministry in charge of inter-Korean affairs announced the result following a six-month test on 80 defectors who had lived in Kilju County and its nearby areas and fled to South Korea after North Korea's first nuclear test in 2006.

The North conducted all of its six nuclear tests at the Punggye-ri nuclear test site, located in Kilju County in the country's northeastern province.

A chromosome aberration analysis, which offers a glimpse of an individual's lifetime accumulated radiation exposure, showed that 17 examinees — including five from Kilju County — reported figures higher than the minimum detection threshold of 0.25 Gray (Gy), the Korea Institute of Radiological and Medical Sciences said in a report compiled on behalf of the Korea Hana Foundation, a ministry-affiliated institution that supports defectors.

The report, however, noted that two of the 17 examinees were likely exposed to radiation after their entry to South Korea, citing an earlier test of the individuals conducted in 2016. The results of five examinees were not statistically significant, it added.

North Korean soldier guards Tunnel No. 2 at the North Korea's only known nuclear test site in Punggye-ri, North Hamgyong Province, May 25, 2018. Yonhap

An official at the organization stressed that while nuclear tests could have affected the analysis, the results could also have been affected by factors like age, drinking habits and exposure to medical radiation or toxic substances, such as pesticides.

"We cannot specify the extent of how much individual factors influenced the results," the official said, adding that more evidence is needed to scientifically confirm a potential link between the results and the North's nuclear tests as the latest findings are within the range of results that could occur solely due to medical radiation.

A contamination analysis, including a urine test, showed that none of the examinees showed a significant level of radioactive contamination, the report said.

Despite limitations in conducting the test, such as being unable to secure the radiation score of the drinking water the examinees consumed in North Korea and the small number of examinees, the ministry said it plans to carry out the tests on all relevant defectors going forward.

"Apart from the fact that North Korea's nuclear tests are illegal and intolerable, the government will do its best to continuously monitor the health of defectors with radiation risks and ease their concerns," a ministry official told reporters.

The government carried out similar tests on 40 North Korean defectors in 2017 and 2018. While some showed signs of suspected radiation exposure in medical checkups, test results concluded that it was hard to confirm that the nuclear tests affected them.

In total, 796 North Koreans who used to live in areas near Punggye-ri have defected to South Korea since North Korea's first nuclear test in 2006. (Yonhap)