Traces of cancer-causing dioxin were found in an environmental test conducted in 2004 inside a U.S. Army base where drums of the toxic defoliant Agent Orange were allegedly buried decades ago, according to a report on the results of the test released Thursday. The U.S. military-commissioned survey conducted by a local company, however, detected an unusually high level of heavy metals and various other chemicals such as volatile organic compounds (VOCs) and pesticides inside the camp, it said. Officials said the results do not directly indicate that the toxic defoliant was buried there because the amounts of dioxin found were very tiny and there can be various other ways of generating the material. The U.S. Army\'s release of the 2004 report received high media attention as disputes continue over allegations by retired U.S. soldiers that they helped bury large amounts of the defoliant in the 1970s inside Camp Carroll in the rural city of Chilgok, 300 kilometers southeast of Seoul. Agent Orange is a toxic chemical that was widely used on trees and plants during wars to make all their leaves fall off. About 28,500 U.S. troops are stationed in South Korea, a legacy of the 1950-53 Korean War, which ended in an armistice. The report by local construction firm Samsung C&T Corps. showed that 2.04 and 0.753 parts per trillion of dioxin were respectively extracted in soil samples from District 41 and District D of the camp. The dioxin level is lower than the 1 part per billion threshold set by American health authorities to determine proper ground for human dwelling. In groundwater samples extracted from wells inside the military base, dioxin levels reaching up to 3.36 parts per quadrillion were detected. Groundwater containing dioxin of more than 30 parts per quadrillion is determined inappropriate for drinking, according to U.S. health standards. The levels of dioxin found in water and dirt are deemed not critically threatening to human health, the study showed, confirming findings of a joint investigation earlier in the month between the U.S. and South Korean governments. The results also showed the sample water and soil contained excessive amounts of other life-threatening chemical compounds. One sample showed ground near the camp contained 245 milligrams of the toxic chemical tolune per every kilogram of dirt, far higher than the local maximum allowable level of 20 milligrams. The study also found unacceptable levels of heavy metals and pesticides in water samples. After about a two-week test, the joint investigation team said it only found dioxin ranging from 0.001 to 0.010 picograms per liter in the samples taken from nearby streams and wells. The joint U.S.-Korea team plans to make public the final results of its months-long investigation in early July.