South Korea will offer radiation testing to 881 North Korean defectors after concerns were raised about their exposure to the North's nuclear tests.
It comes after a research report warned that residents around Punggye-ri, the main nuclear testing site, could be exposed to radioactive leaks in water. บาคาร่าauto
The Transitional Justice Working Group (TJWG) estimates that up to half a million residents are at risk.
It also potentially affects people in China, South Korea and Japan.
The group - which was established in Seoul in 2014 by activists and researchers from South Korea, North Korea, US, UK and Canada - analysed publicly available data and open-source intelligence for its latest report.
North Korea last tested a nuclear bomb in 2017 - the most powerful of six tests conducted at Punggye-ri.
It said the tests were conducted safely, but scientists have long raised fears that radioactive material might have escaped into the surrounding soil and groundwater.