Monitoring and radioecological characteristics of radiocesium in Japanese beef after the Fukushima nuclear accident

After the Fukushima nuclear accident, beef proved to be a problematic food item with several exceedances entering the market. The reason was contaminated rice straw that was fed to cattle. Japanese authorities responded quickly to the exceedances and made beef one of the most-monitored food items after the Fukushima accident with more than a million samples within 5 years. Activity levels dropped quickly and are now considerably below the regulatory limit. No exceedance of the regulatory limit was observed after October 2012. The monitoring campaign focuses on the pre-market to catch any exceedances before they reach the consumer. The analysis also showed that some late beef samples exhibited an unusually high 134Cs/137Cs activity ratio. The reason for this is unknown.