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Home > Safety of Water & Food > Safety of Water & Food > Q&A - Monitoring of radioactive substances in agricultural products 

Q&A - Monitoring of radioactive substances in agricultural products 

2019年4月19日更新 Update

1.How are radiation screenings on farm products carried out?


In Fukushima Prefecture, a system for testing radiation in farm products to ensure safe distribution and consumption is set in place where environmental radiation of agricultural, forestry and marine products are monitored in times of emergency under national guidelines, as well as voluntary inspections conducted by producers at production centers including but not limited to inspections on all gross quantity bags of rice.

Emergency environmental radiation monitoring on agriculture, forestry and marine products are carried out in all affected cities and prefectures, including Fukushima and is based on " concepts of inspection, planning and the establishment and cancellation of items and areas to which the restrictions of distribution and/or the consumption of foods concerned applies " that the Nuclear Emergency Response Headquarters (General manager: Prime Minister) of the national government established.

Based on these guidelines, the prefecture establishes sampling plans and performs sample extractions/measurements.

Monitoring results are available on the prefecture's homepage and also released to the press.

2.What items are targeted for monitoring?


The prefecture monitors all agriculture, forestry and marine products produced and harvested within Fukushima Prefecture purposed for distribution and sale.

In FY2017, we carried out targeting at grains, vegetables, fruit, livestock products, 519 items including marine product.

Note: The number of the items according to food group and the number of inspection (FY 2017)

Food group Number of items Number of inspections
Grains ※Brown rice 1 5
Other grains 13 433
Vegetables, fruit 255 2,855
Livestock products Raw milk 1 398
Meat 5 3,578
hen's egg 1 111
Pasture grass, feed crop - 680
Marine products 178 9,288
Wild vegetables, mushrooms 61 2,111
Other 4 86
Total 519 19,545

※The number of brown rice inspections are the results of detailed inspections.

Related links

3.How is the reference level for radioactive substances in farm products set?


The Food Sanitation Act establishes the reference level for radioactive materials found in food including farm products where if one were to continue eating these products throughout one's life, the result of consuming products with radioactive materials are sufficiently small and at a safe enough level (1mSv a year or less) to not cause any health problems.

The reference level for radiocesium in "drinking water" "milk" "baby food" and "general food" are each set based on their consumption quantity.

The Limits on radioactive materials in foods : Reference Levels

Categories Limit (Bq/kg)
Drinking water 10
Milk 50
General Foods 100
Infant Foods 50

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4.Are nuclides other than radiocesium inspected?


Although the reference level set by the government targeting food including agricultural products was established to detect cesium, the main substance released from the Fukushima Daiichi nuclear disaster, all nuclides with a longevity greater than half a year are also included in the reference level.

With consideration to contribution ratios, the reference level for radiocesium are decided beforehand with leeway so that additional radiation exposure does not exceed 1mSv a year even if other nuclides get into food such as farm products.

5.In monitoring up until now, how much farm products exceeded the reference level?


We had 10 (0.05% of the whole) standard value excess in FY2017.

FY2013: 419 cases (1.5% on the whole), FY2014: 113 cases (0.4% on the whole), FY2015: 18 cases (0.08% on the whole), FY2016: 6 cases (0.03% on the whole). Basically, those real numbers and ratios are on a downward trend.

Number of emergency environmental radiation monitoring of agriculture, forestry and marine products

           FY2014            FY2015            FY2016           FY2017 
 Number of inspectionsCases where reference level exceededNumber of inspectionsCases where reference level exceededNumber of inspectionsCases where reference level exceededNumber of inspectionsCases where reference level exceeded
※Brown rice20920050
Grains (Excl. Brown rice)2,47322,724270504330
Vegetables, fruit5,85004,58503,79302,8551(*1)
Raw milk4080413041503980
hen's egg1400144014301110
Pasture grass, feed crop1,527111,148092206800
Marine products9,688759,21579,50549,2888
Wild vegetables, mushrooms1,564251,56271,83222,1111

※The number of brown rice inspections are the results of detailed inspections.

*1  Chestnuts from the designated sites (not distributed in the market since October 2012). 

6.Are farm products exceeding the reference level distributed?


Based on the Special Measures for Nuclear Disaster Act and the Food Sanitation Act, production centers (communities, and former municipalities. Regarding marine products, sea areas, swamps, and rivers) with items that exceeded the reference level for radioactive substances in food products are ordered to be placed under distribution restrictions by the government or a voluntary restriction is placed by the prefecture as a whole. Items falling under these production centers are never distributed.

National monitoring results from inspection results of radiological substances within food are available. (Ministry of Health, Labour and Welfare homepage)

7.Are farm products below the reference level really safe?


The current reference level, established by the national government, is made to be at an adequate level where effects of continued consumption of radioactive material found in agricultural products are small and safe (1mSv a year or less). 

It has been said that there is not enough information on the dangers of exposure to low levels of radiation. However, low levels of radiation within 100 mSv are thought to be so small that the effects can not be verified scientifically.

8.How are distribution restrictions established and cancelled based on monitoring results?


In cases where monitoring results show that agricultural products containing radiocesium exceed the reference level, the prefecture will immediately request the municipality be placed under a voluntary distribution restraint.

Afterwards, additional inspections are performed on the applicable items within the production centers and to outlying areas with voluntary distribution restraints. The government (Nuclear Emergency Response Headquarters) will determine necessary distribution restrictions and assess the questioned area.

When lifting restrictions, for example in the case of vegetables, in one municipality three or more areas are subjected to radiocesium inspections and fixed inspections are conducted on every item.

Restrictions are lifted if within the most recent month inspection results are below the reference level and when predictions can be made stating results exceeding the reference level will not appear.

Flowchart from Monitoring to Lifting of Restrictions

From monitoring to lifting restrictions flowchart

Based on: "Considerations regarding the implementation and lifting of the items and areas subjected to the inspection plan and the shipment restrictions" (revision released by the Nuclear Emergency Response Headquarters, March 20, 2015)

9.What is the difference between distribution restrictions and voluntarily distribution restraints?


Distribution restrictions are instructions dependent on the national government (Nuclear Emergency Response Headquarters) and voluntarily refraining distribution restraints are requests dependent on the prefectural governor.

In such cases where monitoring results conducted by the prefecture illustrate agricultural products containing an exceeded level of radiocesium the prefecture immediately requests that the municipality producing these products be placed under voluntarily distribution restraints.

In production centers and outlying areas where restraints were called for, the national government (Nuclear Emergency Response Headquarters) confirms detection circumstances of concerned items and necessary distribution restrictions while also passing decisions on the questioned area.

10.How are "harvest" "consumption" and "distribution" different in terms of voluntarily distribution restraints and distribution restrictions?

Voluntary restraints on harvesting
The prefecture requests that vegetables, fruit and some types of grains be voluntarily restrained.
Regardless of intention for sale, distribution or personal use the prefecture desires that harvests of applicable items be voluntarily restrained.
Voluntary restraints on fish harvesting
Prefecture requests that some classes of fish (freshwater fish) found in inland fisheries be voluntarily restrained.
The prefecture desires that marine harvesting techniques including angling be voluntarily restrained.
Consumption restrictions
The national government has restricted vegetables and certain types of mushrooms.
There are restrictions in consumption (eating) of foods such as certain types of wild mushrooms.
Distribution restrictions
Instructions for restrictions and requests for voluntarily distribution restraints are carried out by the national government or the prefecture.
In addition, distribution with intention to sell at markets, direct sale offices or to give out free of charge are all labeled as "distribution".

11.Presently, what farm products are under distribution restraints or consumption restrictions?


Farm products that have requests to be refrained from consumption and/or distribution reflect monitoring results which are frequently updated.

We publish information on our home page about farm products in Fukushima prefecture that have restrictions/restraints on them.

Please refer to the link below concerning items/food products or production centers that have been requested to refrain from consumption or distribution.

12.Regarding vegetables that cannot be distributed, are there any problems with personal consumption?


We do not recommend consumption of vegetables with distribution restrictions.

In addition, we also provide basic inspections to detect radioactive substances within vegetables wanted to be consumed personally. For details, please contact your municipality in Fukushima Prfecture.