SEOUL — North Korea has long maintained that all six of its nuclear weapons tests were conducted safely.
But on Tuesday, a Seoul-based human rights group warned that radioactive contamination may have spread through groundwater from the North’s Punggye-ri nuclear test site, potentially jeopardizing the health of people in North Korea and neighboring countries.
The Transitional Justice Working Group said in its report that radioactive materials could have affected tens of thousands of North Koreans living near Punggye-ri and spread to China, South Korea and Japan through mushrooms and other agricultural products smuggled out of the country.
North Korea has conducted six underground nuclear tests at Punggye-ri between 2006 and 2017. The country claims no harmful materials were released after the tests. But outside experts have raised fears of the possible escape of radioactive material into the environment.
When the North invited international journalists to Punggye-ri in 2018, it confiscated their radiation detectors.
North Korea’s Missile Tests
An increase in activity. In recent months, North Korea has conducted several missile tests, hinting at an increasingly defiant attitude toward countries that oppose its growing military arsenal. Here’s what to know:
U.N. resolutions. Tensions on the Korean Peninsula started rising in 2017, when North Korea tested three intercontinental ballistic missiles and conducted a nuclear test. The United Nations imposed sanctions, and Pyongyang stopped testing nuclear and long-range missiles for a time.
Failed diplomacy. Former President Donald Trump met with Kim Jong-un, the North Korean leader, three times between 2018 and 2019, hoping to reach a deal on North Korea’s nuclear and missile programs. After the talks broke down, North Korea resumed missile testing.
An escalation. North Korea started a new round of testing in September 2021 after a six-month hiatus. It subsequently completed several tests, including the firing of multiple intermediate-range and intercontinental ballistic missiles, that violated the 2017 U.N. resolutions.
New provocations. Mr. Kim has launched a record number of missiles and focused on developing new ones in 2022. The North Korean leader has said that a “neo-Cold War” is emerging and has vowed to expand his country’s nuclear capabilities against South Korea “exponentially.”
In 2015, South Korea’s food safety agency detected nine times the standard level of radioactive cesium isotopes in mushrooms that had been smuggled from North Korea and sold in South Korea disguised as Chinese produce.
Following the North’s last nuclear detonation in 2017, a series of small earthquakes was reported from near the testing site, raising fears of underground cave-ins and a possible contamination of groundwater.
North Korean defectors living in South Korea who once lived near the testing site have also reported observing strange illnesses in their North Korean neighborhoods. Such reports prompted South Korea to test 40 North Korean defectors who had been near the testing site in 2017 and 2018.
Nine of the defectors had symptoms that could be attributed to radiation exposure. But South Korean scientists said they could not establish a link between those symptoms and the nuclear test site because of a lack of data.
On Tuesday, the Transitional Justice Working Group urged South Korea to test all 160 North Koreans in the South who came from Kilju, a county that includes Punggye-ri, or all 881 escapees who lived in nine cities and counties near the testing site before fleeing to the South.
“North Korea’s nuclear tests threaten the right to life and the right to health of not only the North Korean people, but also of those in South Korea and other neighboring countries,” said Lee Younghwan, the group’s executive director.
The South’s Unification Ministry said on Tuesday that it was willing to consider reopening an investigation if North Korean defectors report symptoms of possible radioactive exposure and ask for medical assistance.
During the pandemic, the number of defectors from North Korea arriving in the South plummeted from 1,047 in 2019 to 67 last year.
The new warning about the testing site came amid signs that North Korea, one of the most isolated countries in the world, was preparing to resume nuclear weapons tests. In 2017, the chief of South Korea’s weather agency told lawmakers in Seoul that if North Korea detonated another powerful nuclear device at Punggye-ri, it could destabilize the mountain test site enough to leak radioactive materials.
Officials in Washington have warned for months that North Korea was ready to conduct another underground nuclear test. The apparent delay may be caused by technical difficulties amid food shortages in the North or pressure from China to avoid creating more regional instability, according to analysts.
In the past week, North Korea has vowed to take “persistent and strong” countermeasures against the joint military drills the United States and South Korea have planned for this spring. It launched an intercontinental ballistic missile on Saturday. Kim Yo-jong, the sister and spokeswoman for the North’s leader, Kim Jong-un, also warned Seoul and Washington of launching more missiles into the Pacific, threatening to use the ocean “as our firing range.”