The hunt is on for the source of low level radiation detected in the atmosphere "across Europe" over the past several days, nuclear officials said today. Trace amounts of iodine-131, a type of radiation created during the operation of nuclear reactors or in the detonation of a nuclear weapon, were detected by the Czech Republic's State Office for Nuclear Safety starting two weeks ago. After the group reported its findings to the International Atomic Energy Agency, the Agency released a statement today revealing similar detections had been made "in other locations across Europe."

The IAEA said the current levels of iodine-131 are not high enough to warrant a public health risk, but the agency still does not know the origin of the apparent leak and an official with the agency would not say where exactly it has been detected outside the Czech Republic.

The IAEA said it does not believe the radiation was left over from the nuclear disaster at Japan's Fukushima Daiichi plant in March and the Czech Republic's State Office for Nuclear Safety could only say the source was "likely outside the territory of the [Czech] Republic."

"Anywhere spent nuclear fuel is handled, there is a chance that... iodine-131 will escape into the environment," the U.S. Environmental Protection Agency says on its website.

According to the EPA, iodine-131 can get into the environment after leaking from cracked fuel rods in nuclear plants and, when ingested in higher doses, can lead to thyroid problems. This particular type of radiation is relatively short-lived, with an estimated half-life of about eight days.