Seoul, May 16 : South Korea has kicked off radiation exposure tests on North Korean defectors who hailed from areas near the reclusive country's Punggye-ri nuclear testing site, an official at Seoul's Unification Ministry said on Tuesday. The radiation testing, which started on Monday, is expected to be completed by November, with its outcome likely to be made public in late December, Yonhap News Agency quoted the official as saying. The test will be conducted on 89 defectors who had lived in Kilju county and its nearby areas, and escaped the North after the country'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 in the country's northeastern province. The South Korean government previously held such similar tests on 40 North Korean defectors in 2017 and 2018. Among the 89 defectors to undergo the testing, nine will be those who were suspected of having been exposed to radiation during the government's previous tests. In a report released in February, the Transitional Justice Working Group, an advocacy group for the North's human rights, said hundreds of thousands of residents living in the area near the Punggye-ri site are at risk of exposure to radioactive materials being spread by underground water. /IANS