https://phys.org/news/2018-07-amounts-isotope-fukushima-disaster-california.html

To find out, the pair used the same technique used to test bottles of wine produced after Chernobyl—namely, using sensors to measure gamma rays in proportion to the isotope levels emitted from unopened bottles. The researchers report that this approach failed—likely because the levels of the isotope were too low. Undeterred, they opened some of the bottles and tested them more closely. This involved heating a sample of wine to 100°C for an hour and then heating it some more to 500°C for eight hours. This resulted in reducing the wine to ash. The research pair then tested the ashes with a gamma ray detector and found trace amounts of cesium-137.

The researchers reiterate that the levels they found pose no threat to human health—officials with California's health department have also issued statements promising that the isotopes found in California wines (or other agricultural products) pose no threat to human health.

                                                            
                                    
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