The mountainous site that North Korea is using for its underground nuclear tests is heavily contaminated and has been turned into a “wasteland,” according to a report by South Korea’s Chosun Ilbo newspaper.

Defectors from the North are quoted as saying that 80% of the trees at the site in Kilju, North Hamgyong Province, about 80 km from the Chinese border, have died. Underground wells have also reportedly run dry and babies are being born with birth defects after six nuclear tests in the area.

Chosun Ilbo says the information is based on interviews with 21 defectors who formerly lived in Kilju in the last two years, conducted by the Research Association of Vision of North Korea, a defector-related group.

“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.

Another defector 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.”

Suh Kyun-ryul, a professor of nuclear engineering at Seoul National University, noted that the contamination is related to earth events triggered by the tests. “Due to the collapsed ground layer, fissures must have formed underneath, leading to contamination of the underground layer and water supply,” Suh said.

Japan’s TV Asahi reported recently that a tunnel collapse in a mountain test facility following the country’s sixth nuclear test in early September has killed more than 200 people.

Researchers from the Chinese Academy of Sciences’ Institute of Geology and Geophysics reportedly warned a North Korean delegation in Beijing in late September about an implosion at the Punggye-ri nuclear facility.