Comprehensive analysis of a decade of cumulative radiocesium testing data for foodstuffs throughout Japan after the 2011 Fukushima Daiichi Nuclear Power Plant accident

Abstract

The unexpected accident at the Fukushima Daiichi Nuclear Power Station in Japan, which occurred on March 11th, 2011, after the Great East Japan Earthquake and tsunami struck the north-eastern coast of Japan, released radionuclides into the environment. Today, because of the amounts of radionuclides released and their relatively long half-life, the levels of radiocesium contaminating foodstuffs remain a significant food safety concern. Foodstuffs in Japan have been sampled and monitored for 134,137Cs since the accident. More than 2.5 million samples of foodstuffs have been examined with the results reported monthly during each Japanese fiscal year (FY, from April 1st to March 31st) from 2012 to 2021. A total of 5,695 samples of foodstuffs within the “general foodstuffs” category collected during this whole period and 13 foodstuffs within the “drinking water including soft drinks containing tea as a raw material” category sampled in FY 2012 were found to exceed the Japanese maximum permitted level (JML) set at 100 and 10 Bq/kg, respectively. No samples from the “milk and infant foodstuffs” category exceeded the JML (50 Bq/kg). The annual proportions of foodstuffs exceeding the JML in the “general foodstuffs” category varied between 0.37% and 2.57%, and were highest in FY 2012. The 134,137Cs concentration for more than 99% of the foodstuffs monitored and reported has been low and not exceeding the JML in recent years, except for those foodstuffs that are difficult to cultivate, feed or manage, such as wild mushrooms, plants, animals and fish. The monitoring data for foodstuffs show the current status of food safety risks from 134,137Cs contamination, particularly for cultured and aquaculture foodstuffs on the market in Japan.

137Cesium (137Cs) assessment in wild boars from northwestern Italy

“…The pollution resulting from nuclear power plant accidents (e.g., Chernobyl) is still present and continues to cause a small increased risk of stochastic radiation effects (cancer and heritable effects) [ 7 ]. To provide a high level of protection from this risk, mandatory risk assessments must be performed using reliable data [ 4 , 18 ] and in a regular manner due to the very long half-lives of certain radionuclides, such as 137 Cs [ 8 ].…”

“…Anthropogenic sources of radionuclide contamination became the primary source in the second half of the twentieth century [ 2 , 4 , 6 ].…”

“…Moreover, assessing the effects of radionuclides on natural flora and fauna is important not only because of the potential impact of contamination on forest ecosystems but also because of their possible consumption by humans in the form of fruit, mushrooms, wild game meat and meat products [ 1 , 4 , 10 ]. In fact, it has been demonstrated that exposure to radionuclides through the consumption of contaminated food has the potential to affect a large part of the population and poses the most relevant radiological risk of chronic accumulation once measures have been taken [ 6 , 7 ].…”

Exploring simple ways to avoid collecting highly 137Cs-contaminated Aralia elata buds for the revival of local wild vegetable cultures

“…However, the Fukushima Daiichi Nuclear Power Plant accident in March 2011 resulted in radionuclide contamination, leading to the termination of such activities [ 2 , 3 ]. Collecting various wild vegetables is restricted in some contaminated areas due to radiocesium concentrations exceeding the Japanese reference level (100 Bq/kg) [ 4 , 5 ]. Among the vegetables, the buds of Koshiabura ( Eleutherococcus [ Chengiopanax ] sciadophylloides [Araliaceae]), which is known as the “Queen of sansai ,” exhibits particularly high radiocesium concentrations compared to other wild vegetables [ 6 – 8 ].…”

Simple ways to avoid collecting highly137Cs-contaminatedAralia elatabuds

“…However, the Fukushima Daiichi Nuclear Power Plant accident in March 2011 resulted in radionuclide contamination, leading to the termination of such activities [2,3]. Collecting various wild vegetables is restricted in some contaminated areas due to radiocesium concentrations exceeding the Japanese reference level (100 Bq/kg) [4,5]. Among the vegetables, the buds of Koshiabura (Eleutherococcus [Chengiopanax] sciadophylloides [Araliaceae]), which is known as the "Queen of sansei," exhibits particularly high radiocesium concentrations compared to other wild vegetables [6][7][8].…”