SEOUL, South Korea — Steve House can’t stop thinking about the day in 1978 when he says he helped bury toxic Agent Orange at a U.S. military base in South Korea, hauling rusting drums to a ditch from a warehouse that soldiers called “voodoo land.” After decades of silence and countless hours of suffering that he links to exposure to the dangerous herbicide, House is one of three former American soldiers whose accounts have sparked a joint U.S.-South Korean investigation. The allegations have set off a media firestorm in South Korea, fueling daily television news shows, front-page newspaper stories and worries among people near the base about groundwater safety, cancer and drops in the price of land. House claims that soldiers at Camp Carroll in southern South Korea took a large number of 55-gallon drums, fragile with rust and stamped with the words “Agent Compound Orange,” from the mysterious, restricted warehouse and carried them over crisp dead grass into a deep ditch the length of a soccer field. “This is a burden I’ve carried around for 35 years,” House, 54, said in a phone interview with The Associated Press from his home in Apache Junction, Ariz. “It’s bugging the hell out of me. I don’t want to take this to my grave.” Two other former soldiers who served with House also said in interviews with KPHO-TV in Arizona, which first reported the claims, that they buried the toxic chemical; one estimated 250 drums. Still sensitive to massive anti-U.S. demonstrations in South Korea in recent years, American officials have responded with remarkable speed. Since the claims surfaced in mid-May, the U.S. military has acknowledged that it buried many drums of herbicide and other chemicals at the base in 1978. The chemicals were then dug up and disposed of somewhere away from the base. But officials are still trying to find out where they were taken and whether Agent Orange was included in the burial. The U.S. is jointly investigating the Camp Carroll site with South Korea, and on Thursday, U.S. and South Korean officials invited the media to watch a search for buried objects using ground-penetrating radar. Officials said the results must still be interpreted. “Our analysis will be deliberate, thorough and transparent,” 8th Army commander Lt. Gen. John Johnson said in a statement. “We want to assure ourselves and the Americans and Koreans on and around Camp Carroll that we are taking the right steps to safeguard their health and safety.” The quick action by the American military and the intense Korean media interest reflect the often tense relationship South Koreans have with the 28,500 U.S. troops stationed here to help deter North Korean aggression. Liberals have often pushed for Seoul to assert its independence from ally Washington, and anti-Americanism has previously spurred massive rallies. When soldiers involved in a 2002 traffic accident that killed two schoolgirls were exonerated, weeks of rage helped former President Roh Moo-hyun win a come-from-behind election victory with a pledge not to “kowtow” to Washington. South Korean news organizations have generally praised the U.S. response this time. But the swift investigation also “reflects the severity of the problem,” the Korea JoongAng Daily newspaper said in an editorial. “Both allies must keep in mind that any effort to distort or cover up the truth will only exacerbate the situation.” Agent Orange contains dioxin, which scientists say can cause cancer, deformities and birth defects. It was used during the Vietnam War, and South Korea says it also sprayed the chemical along its border with North Korea in the late 1960s to kill dense foliage that North Korean infiltrators used for cover. Buried dioxin could leak from containers and enter surrounding groundwater, possibly contaminating drinking water. Environmental tests have confirmed extremely high levels of dioxin in people, fish and soil near a former U.S. air base where American troops stored the herbicide during the Vietnam War. Lt. Col. Jeffrey Buczkowski, an 8th Army spokesman, said Agent Orange is generally destroyed by high-temperature incineration at sea or on a remote Pacific island. Residents near Camp Carroll, many of them elderly, worry about groundwater safety and cancer, Gong Hyun-chul, a local official near the base, said in an interview. The reports have soured land prices and agricultural sales, Gong said, and activists plan protest rallies near the camp. Any scandal over contamination could influence other areas in Asia that host American troops. There are 47,000 U.S. troops in neighboring Japan, and Washington is trying to orchestrate a delicate relocation of one of its bases on the island of Okinawa, where anger against U.S. troops is high. Although the Agent Orange investigation is still in its early stages, the U.S. military has released a statement saying a 1992 study found “that a large number of drums containing chemicals, pesticides, herbicides and solvents were buried” in 1978 near the area mentioned by House and others. The study didn’t specifically identify Agent Orange. The military removed the material and 40-60 tons of soil from the area in 1979-80, the statement said, dumping it somewhere “off-site.” Officials are investigating why the material was buried in the first place and what happened to it after it was dug up, the statement said. More testing at the area in 2004 revealed trace amounts of dioxin, the statement said, but “the amount was deemed to be no hazard to human health.” House, however, blames his work at Camp Carroll for type II diabetes and nerve damage — both of which have been linked to Agent Orange — and other serious health problems that make him too sick to work. “I’m falling apart,” House said. “I got microwaved on the inside from what’s in the ground” in South Korea.