The U.N. nuclear agency is reporting "very low" — but higher than usual — levels of radiation in the Czech Republic and elsewhere in Europe.
The International Atomic Energy Agency says the "very low levels of iodine-131 have been measured in the atmosphere over the Czech Republic" and elsewhere on the continent.
Its statement on Friday said the current levels do not seem to pose a public health risk.
IAEA says the cause is not known, but it is not the result of Japan's Fukushima Daiichi nuclear disaster, which spread radiation across the globe in March.
The agency says the radioisotope will lose much of its radiation in about eight days and that the agency is investigating.