Suh Kyun-ryul, a professor of nuclear engineering at Seoul National University, said, "Due to the collapsed ground layer, fissures must have formed underneath, leading to contamination of the underground layer and water supply."

Another said, "I spoke on the phone with family members I left behind there and they told me that all of the underground wells dried up after the sixth nuclear test."

"I heard from a relative in Kilju that deformed babies were born in hospitals there," one defector said. Another said people in Kilju drink water that comes down from Mt. Mantap in Punggye-ri, where the nuclear test site is located, and they are worried about contamination from radiation.

The Research Association of Vision of North Korea, which includes North Korean defectors, interviewed 21 defectors who used to live in Kilju in the last couple of years.

North Koreans who defected from the region said 80 percent of trees that are planted die, underground wells have run dry and babies are being born with defects.

North Korea's nuclear test site in Kilju, North Hamgyong Province is turning into a wasteland after six underground nuclear tests, according to witness accounts.

Defectors testified that officials do not warn locals before conducting underground nuclear tests. One defector who escaped North Korea in 2010 and claims to have experienced two nuclear tests in Punggye-ri said, "During the first nuclear test (October of 2006) and second one (May of 2009), only family members of soldiers were evacuated to underground shafts. Ordinary people were completely unaware of the tests."

The population of Punggye-ri consists of soldiers who guard the nuclear test site and a few farmers who manage plantations affiliated by the facility. The defector said, "Prior to nuclear tests, around two tests involving only detonators take place, and locals are mobilized to dig deep holes for those tests. I personally saw corpses floating down the river with their limbs severed."

Kim Tae-woo, a former head of the Korea Institute for National Unification, said, "In several other countries casualties have been reported from detonator tests. Considering North Korea's dismal human rights track record, I doubt that stringent safety measures were taken prior to the detonator tests."

Other defectors said local specialties like trout and pine mushrooms have disappeared from the region. "Trout and pine mushrooms were sent to senior party officials as gifts in the 1980s, but they disappeared after the first nuclear test in 2006," one said.

Another defector who used to work as a forestry official in Kilju said, "If you plant trees in the mountains there, 80 percent of them die. You can blame it on poor planting, but the number of trees that die is higher than in other mountains."

Locals are forbidden from going to Pyongyang. One source who has visited Kilju since the sixth nuclear test said, "Kilju locals who made appointments in a large hospital in Pyongyang were not allowed to enter the capital after the sixth nuclear test."

Officials are trying hard to prevent accounts from inside Kilju spreading to other parts of the North. One said, "People who boarded trains to the border with samples of soil, water and leaves from Kilju county were arrested and sent to prison camps."

The Unification Ministry here has been conducting radioactive contamination tests of 30 North Korean defectors from Kilju since last month.

