Seoul, South Korea – Deserters living near North Korea's nuclear testing site say they believe they are exposed to radiation and fear for the health of family members still living there.
With a height of approximately 5 feet, Lee Jeong Hwa walks with a slight limp. Middle-aged, with a gray-gray complexion and deep dark brown eyes, Lee says he feels constant pain.
But at home, things are much worse, she says.
"So many people died that we started calling it 'ghost disease'," he said. "We thought we were dying because we were poor and we ate poorly, now we know what the radiation was."
While Lee rubs his aching right leg in the office of SAND, a non-governmental organization in Seoul that defends human rights in North Korea, he recounted how he was caught trying to flee the country in 2003.
He finally escaped in 2010 from his home in Kilju County, site of North Korea's nuclear testing site, Punggye-ri.
For the past seven years, Lee lived in the north, the leader of the time, Kim Jong Il, detonated two nuclear bombs near his home, since Kim's death in 2011, his son and The heir, Kim Jong Un, has tested four more, saying that the one tested in September was a hydrogen bomb.
According to the World Health Organization, radiation can affect the functioning of tissues and organs, depending on the level of exposic In lower doses, he says, there is a long-term risk of cancer.
Lee and other defectors are inflexible that these tests have had a detrimental effect on their health. The scientific evidence and the opinion of the experts, however, are not so conclusive.
The Unification Ministry of South Korea has been testing Lee and 29 other Kilju deserters for radiation contamination. Lee told NBC News that the results of his tests have returned, and they are clean.
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In addition to the testimony of Lee and others, it is difficult to verify that radiation is the cause of generalized diseases, such as leukemia . and other cancers, which the defectors say have been destroying Kilju.
Suh Kune-yull, professor of nuclear engineering at the National University of Seoul (SNU), says the reality is that researchers suffer from a "total lack of data".
"I do not think they're lying," says Kune-yull about the defectors. "We have to take his word, but I do not have much reliable information."
A spokesman for the Korean Nuclear Safety Institute told NBC News that "it's supposed" that exposure to radioactive material from the underground test site is excessive, but it is difficult to confirm.
Lee and Rhee Yeong Sil, another defector in the SAND office, say that for years they had no idea that North Korea was testing nuclear devices, they ignored the tremors and only discovered the truth after fleeing their homeland.
Rhee, who is 60 years old and defected in 2013, says he lived a few kilometers from the Punggye-ri test site and that his neighbor gave birth to a deformed baby.  "We could not determine the bad of the baby, because he had no bads," says Rhee. "In North Korea, deformed babies usually die, so the parents killed the baby."
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Some of Rhee and Lee's claims about radiation exposure date back to the 1990s and even the 1980s, raising questions about whether more than just Nuclear test could have contaminated the environment and made people sick.
While the country's first nuclear test was not until 2006, deserters tell stories of trout that died in the mountain streams and the precious pine mushrooms disappeared much earlier.
SAND President Choi Kyung Hui, who is also a deserter but not from Kilju, suggested military activity in Punggye-ri in previous years to the tests could explain the contamination in the area.
But Ferenc Dalnoki-Veress, a resident scientist at the James Martin Center for Nonproliferation Studies in Monterey, California, has doubts that radiation will harm the environment and the health of the residents.
He said that if any radioactive material had been leaked, even from a collapse of the tunnel reported this month after the sixth test, powerful sensors in the region that "sniff" the atmosphere would have The same thing happens with the previous tests, he said.
Days after the sixth test, the government of South Korea announced that it had detected traces of radioactive xenon, although it never conclusively said where it came from.
Ferenc says it is "very, very unlikely" that it comes from the Punggye-ri site. He is also skeptical of groundwater pollution. Tests near rocks saturated with water, he says, could accumulate steam that expels pollutants into the air. That, he says, does not interest anyone.
Both Lee and Rhee stay in touch with their families when they can, using cell phones smuggled to North Korea from China.
Rhee says his family is sick, with headaches and vomiting, but no medication helps. She is surprised that in her new home, even the rights of animals are protected. But in North Korea, she says, the health of its people is ignored.