The number of cases in which radioactive cesium exceeding Japanese government standards was found in food items dropped to less than 20 percent over a five-year period from fiscal 2012, a health ministry study has found.
The government standards for radioactive cesium came into effect in April 2012, which assumed that half of distributed food products contained the radioactive element generated by the 2011 disaster at the Fukushima No. 1 Nuclear Power Plant. It is set at 100 becquerels per kilogram for common food items, 50 becquerels per kilogram for baby food and cow milk and 10 becquerels for drinking water.
Based on central government guidelines, 17 prefectural governments, counting Tokyo, check food products in which radioactive cesium is likely to be detected, including items that have been distributed, for the radioactive element. Other local governments have also been independently inspecting such food products to confirm their safety. A Health, Labor and Welfare Ministry research team analyzed data compiled by local governments, excluding that of beef, which has an extremely low detection rate for cesium, as well as products that go through bag-by-bag inspections such as rice from Fukushima Prefecture.
As a result, the number of cases that exceeded the threshold set under the Food Sanitation Act totaled 2,359 of 91,547 food products inspected in fiscal 2012. In fiscal 2013, it was 1,025 out of 90,824 products, 565 out of 79,067 in fiscal 2014, 291 out of 66,663 in fiscal 2015 and 460 out of 63,121 in fiscal 2016.
Broken down by categories, 641 cases of food items among agricultural produce were found to have exceeded the government standards for radioactive cesium and 1,072 cases were detected among fishery products in fiscal 2012, but the figure had dropped to 71 and 11, respectively, in fiscal 2016. For fishery products, this is believed to be attributed to the reduction of cesium concentration in the seawater as the element had diffused in the ocean. It is also believed that the concentration in agricultural items had dropped as a result of decontamination work and other efforts.
At the same time, the number of cases exceeding national standards totaled 493 for game meat in fiscal 2012, and 378 in fiscal 2016. Researchers suspect that because wild animals continue to feed on wild mushrooms and plants with high concentrations of radioactive cesium growing in forests that have not been decontaminated, the figure does not drop among game meat products.
Almost all the foods that exceeded the government standards for radioactive cesium had not been available to consumers as the contamination was detected during inspections before being shipped to markets. However, Akiko Hachisuka of the National Institute of Health Sciences Biochemistry Division who headed the Health, Labor and Welfare Ministry research team says game meat and wild mushrooms need to be prioritized in inspections for the time being and also in the future.
Among wild mushrooms and other products that had been distributed to markets, 19 cases exceeding government standards were reported in fiscal 2012, seven in fiscal 2013, 11 in fiscal 2014, 12 in fiscal 2015 and 10 in fiscal 2016.