Radiation Mystery Solved? Budapest 'Probably' the Source

Nov. 17, 2011 — -- Nuclear officials said today they believe they have traced the source of a massive, but harmless, radiation plume that has spread across the atmosphere in Europe to an institute in Hungary, but the head of the institute disagrees.

The Hungary Atomic Energy Authority said the Budapest-based Institute of Isotopes was "most probably" the source of the continued leak of trace amounts of Iodine-131 into the atmosphere, according to a statement by the International Atomic Energy Institute. Last week the IAEA first announced they received reports of trace iodine-131 detections from countries "across Europe," but had no idea from where the radiation was leaking.

READ: Mystery Radiation Detected 'Across Europe'

According to today's announcement, the HAEA said the leak started on Sept. 8 and was just identified and stopped Wednesday. The IAEA repeatedly said the levels of iodine-131 released into the atmosphere were far too low to pose a public health concern.

A spokesperson for the IAEA also told ABC News the agency had conducted air dispersion modeling with the World Meteorological Organization and those findings pointed to Hungary.

But the head of the Institute of Isotopes, Mihaly Lakatos, told ABC News that while a filtering problem at his organization may be responsible for some of the iodine-131 detected in Hungary, it could not be the source of detections hundreds of miles away in other European nations.

"Maybe partly we have something to do with iodine-131 over Budapest, but not over Europe," Lakatos said. "The distance is too long."

The IAEA told ABC News Wednesday iodine-131, which has a decay half-life of just eight days, had been detected in at least seven countries -- from France to Slovakia and Poland. Before the HAEA's announcement, the IAEA said they were still working to narrow the list of possible sources for the radioactive leak.

In response to Lakatos' objections, the IAEA referred ABC News to the HAEA, who made the claim initially. Representatives there did not immediately responded to requests for comment.

Budapest's Institute of Isotopes produces radioisotopes "for a broad range of application areas, especially healthcare, research and industry," according to its website. Iodine-131 in particular is commonly used in low doses to help treat thyroid issues.