Home > The Great East Japan Earthquake > Questoins and answers on rice, meat and eggs, milk, dairy products, mushrooms, and edible wild plants (as of December 19, 2012)


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Questoins and answers on rice, meat and eggs, milk, dairy products, mushrooms, and edible wild plants (as of December 19, 2012)

Rice

Q: How is the concentration level of radioactive cesium in rice inspected?

A: In order to secure the concentration level of radioactive cesium in rice on the market not exceeding the maximum limit under the regulation of Food Sanitation Law, several measures, depending on the concentration level of radioactive cesium in rice harvested in 2011, are conducted as for rice harvested in 2012.

First, rice farming in 2012 is restricted in the areas where over 500 Bq/kg of radioactive cesium was detected in rice harvested in 2011, as in such area it would have been expected the maximum limit of radioactive cesium for general foods (100 Bq/kg) be detected in rice if harvested in 2012.

In other areas where rice farming is operated in 2012, prefectural governments inspect the concentration of radioactive cesium in harvested rice in line with “Concepts of Inspection Planning and the Establishment and Cancellation of Items and Areas to which Restriction of Distribution and/or Consumption of Foods concerned Applies”, a guideline issued by Government of Japan.

According to the guideline, inspection procedures including sampling density depend mainly on the level of the concentration of radioactive cesium in rice harvested in 2011.

(Note)

  • “The Concepts of Inspection Planning and the Establishment and Cancellation of Items and Areas to which Restriction of Distribution and/or Consumption of Foods concerned Applies”  (12 July 2012) is available on the webpage of MHLW: (PDF:288KB)
  • Detailed information of the regulation of the concentration of radioactive cesium in Japan is available on the webpage of MHLW : New standard limits for Radionuclides in Foods . 

Meat & Eggs

Q: How is the summary of the results of inspections on radioactivity levels in meat and eggs?

A: Until April 1st, 2012, more than 93,000 samples of meat and eggs had been inspected under the provisional regulation stipulating that the maximum limit of the concentration of radioactive cesium for meat and eggs was 500 Bq/kg. Of them, the concentrations of 157 samples (0.17 percent of all samples) were above the maximum limit.

While the new regulation setting out the maximum limit of 100 Bq/kg for general foods came into force on April 1st, 2012, as the transitional measure, the maximum limit of 500 Bq/kg still had applied to beef until September 30.

Since April 1st until September 30, 2012, more than 70,000 meat and egg samples were tested for the concentration of radioactive cesium. Of them, a pork sample’s concentration was above the new maximum limit of 100 Bq/kg. Besides this pork sample, the concentrations of radioactive cesium in 5 beef samples were in the range of 100 Bq/kg to 500 Bq/kg. Although these concentrations were under 500 Bq/kg which was the maximum limit for beef as the transitional measure, since these were over 100 Bq/kg which was the new maximum limit from October 1st, 2012, local governments requested farmers to stop sale. Thus the one pork and 5 beef samples weren’t on market.

(Note)

 

Q:  How is the concentration of radioactive cesium in all meat and eggs currently on market kept under the maximum limit?

A: Only the meat and eggs whose concentrations of cesium are less than the maximum limit are currently on market, resulting from the combination of proper feeding management and inspection as follows.

  • Concentrations of radioactive cesium in meat and eggs are influenced mainly by the concentration of radioactive cesium in feed and drinking water for livestock. Therefore, the Ministry of Agriculture, Forestry and Fisheries established and revised the provisional tolerable radioactive cesium levels for feed and has instructed farmers in cooperation with regional governments not to use feed over this levels or contaminated drinking water.
  • Along with the feeding management, the concentration of radioactive cesium in meat and eggs is inspected by local governments following “the Concepts of Inspection Planning and the Establishment and Cancellation of Items and Areas to which Restriction of Distribution and/or Consumption of Foods concerned Applies", a guideline issued by government of Japan.
  • Radioactive cesium level contained in beef is significantly influenced by feed for cattle. In 7 prefectures (Iwate, Miyagi, Fukushima, Ibaraki, Tochigi, Gunma and Chiba), therefore following the guideline, cesium inspection for beef is conducted on a regular basis, at least once in every 3 months, on all farms. In addition, in 4 prefectures of them (Fukushima, Miyagi, Iwate, and Tochigi) that partly restricts shipment of beef, for more strict inspection, cesium inspection may be required of every single cattle from farms because of their past results or inappropriate feeding management in the past. Cattle from the other farms are inspected at least once in every 3 months before sale.

(Note)

  • “The Concepts of Inspection Planning and the Establishment and Cancellation of Items and Areas to which Restriction of Distribution and/or Consumption of Foods concerned Applies” (12 July 2012)  is available on the webpage of MHLW: (PDF:288KB)

 

Milk, Dairy products

Q: Is raw milk different from milk generally sold for consumers?

A: Raw milk is the milk just milked. It is shipped for dairy factories and not for consumers directly.

 

Q: How milk and dairy products are produced from raw milk?

A: Generally, the raw milk just milked from healthy milk cows by dairy farmers is cooled with 10 degree centigrade or below it at the dairy farmer’s tank, then, it is stored for 2 days. A tank truck collects several dairy farmers’ raw milk. The raw milk is collectively stored at a facility called as Cooler Station, then, it is shipped for dairy factories. A large quantity of raw milk is treated heat sterilizing, and then, is processed to milk and dairy products for consumers.

 

Q: Are milk and dairy products sold safe for consumption?

A: As mentioned above, the safety of the milk and dairy products for consumers’ consumption are secured by conducting proper monitoring against radioactive substances. The raw milk produced at the shipment restrained area cannot be raw material of milk and dairy products for consumers.

 

Q: How inspections to lift the restraint on the shipping of raw milk are conducted?

A: Raw milk is sampled at Cooler Stations (chilled storage facilities for raw milk) or dairy factories and inspected once a week. If the level of the radioactive substances of the raw milk from the same place is below the provisional standard for three times consecutively, the Nuclear Emergency Response Headquarters judges whether the restraint should be lifted or not, by city/town/village of the CS/dairy factory. Even after the lift of the restraint, raw milk is consecutively sampled and inspected once a week.

 

Q: Can you ensure the safety of raw milk by inspecting it not at a farm level, but at a CS level? Isn’t it a problem if you inspect raw milk at the CS level as it would just result in mixing and diluting raw milk that includes radioactive substances beyond the provisional regulation levels with raw milk that has lower level of the substances than the regulation levels?

A: Raw milk produced by dairy farmer is shipped to the factory of dairy industry as a raw material. Raw milk is, therefore, not directly reached to consumers. More specifically, raw milk collected from the dairy farmers in a certain area is usually gathered at the CS, and then, transported to a factory of dairy industry. Raw milk then goes through various processes such as heat sterilization and is finally shipped as various milk/milk products.

Therefore, we understand that, in order to ensure the safety of milk/milk products that are provided to consumers, it is appropriate to monitor radioactive substances not at each dairy farm level, but at the CS level in determining the propriety of enforcing the restraint of raw milk shipment.

For this reason, “Concept of setting and lifting the products and areas for inspection plan and restraint of shipment” notified from the Nuclear Emergency Response Headquarters on April 4 also stated that sampling for raw milk inspection is “conducted at the CS level or at the level of factory of dairy industry”.

 

Q: Which part of the milk label can people find its origin?

A: As for milk and dairy products, the place of the dairy factory, instead of the origin of raw milk, is obliged to indicate as its origin on the label. Therefore, consumers can not judge the origin of raw milk from the label of milk or dairy products in some cases. However, if the level of radioactive substances of raw milk is above the provisional standard, the raw milk cannot be used for the products for consumers because it is restrained for shipment and because each JA or dairy factory checks the name of producers, etc. of raw milk at CS or dairy factory.

 

Mushrooms and edible wild plants

 Q: Is it safe to eat mushrooms and edible wild plants on sale?

A: Mushrooms such as Shiitake cultivated on raw logs in open fields or facilities, Shiitake cultivated on mushroom bed, Nameko, Maitake, Enokitake and edible wild plants are produced in many prefectures. The inspection of radioactive substance on these products is conducted by each prefectural government. If the radioactive substances over the new standard limit for general foods (100Bq/kg) are detected in a product, the Nuclear Emergency Response Headquarters will issue the restriction of the shipment from a municipality where the product was cultivated (Prefectural governments may voluntarily restrain the shipment from the municipality). The inspection of radioactive substance on these products is also regularly, like once a week, conducted in the other areas where the shipment has not been restricted, and the result is publicly announced.

All prefectural governments also decided to label the names of production municipalities and cultivation methods of mushrooms and edible wild plants on the market, so that consumers can know information on cultivation of these products. In addition, for the safe distribution of mushrooms and edible wild plants, prefectural or other government officials patrol the production areas and distribution points to check if the labeling is correct and products cultivated in the shipment restraint areas are not distributed.

 

Q: Why is the shipment of some mushrooms and edible wild plants restrained?

A: The radioactive substances inspection on mushrooms such as Shiitake cultivated on raw logs in open fields or facilities, Shiitake cultivated on mushroom bed, Nameko, Maitake, Enokitake and edible wild plants are frequently conducted  by each prefectural government.

If radioactive substances over the new standard limit for general foods are detected in a product, the concerned prefectural government immediately requests the voluntary restraint of shipment to a municipality where the product was cultivated.

Afterwards, the investigation is also conducted in areas around the shipment restraint municipalities in order to check the regional expansion. The Nuclear Emergency Response Headquarters will issue the restriction of the shipment, if radioactive substances over the new standard limit are detected in the plural municipalities.

The situations of the restriction of the shipment in each prefecture concerning mushrooms and edible wild plants are shown on the websites below (written in Japanese).

Iwate prefecture 

Miyagi prefecture

Fukushima prefecture

Ibaraki prefecture

Tochigi prefecture

Chiba prefecture

 

The Nuclear Emergency Response Headquarters will decide whether to cancell the instruction to restrict the shipment based on the result of inspection in the restricted area on radioactive cesium that all of the level detected at more than 3 points in one municipality within the latest month shows below the new standard limit of general foods.

After cancellation of the instruction to restrict the shipment, the investigation will be conducted with the observation of the growth of Shiitake mushrooms etc.

 

Q: What is the difference between Shiitake mushrooms cultivated on raw logs and those cultivated on mushroom bed?

A:There are several methods to cultivate Shiitake mushrooms. Some are cultivated on raw logs, which is the traditional cultivating method in Japan, while others are cultivated on mushroom bed using sawdust etc.

By the former method, the mycelium is inoculated in the hole of raw logs and left to grow naturally in the forest for a year or so.

By the latter method, the mycelium is inoculated on the growth substrate such as sawdust to which rice bran etc. are added for nutrition. Then Shiitake mushrooms appear and grow in the air-conditioned facility for three months or so.

Raw Shiitake cultivated on mushroom bed account for 84% of total production in Japan, while those grown on raw logs account for 16%. In the inspection conducted from April to May 2012, radioactive substances over the new standard limit were detected in 30% of Shiitake mushrooms cultivated on raw logs, while there was no such case for those cultivated on mushroom bed.

Shiitake mushrooms absorb radioactive substances contained in raw logs and growth substrate. Therefore, the provisional reference index for radioactive substances in raw logs or growth substrate has been utilized in order that radioactive substances in Shiitake mushrooms do not exceed the new standard limit for general foods.

The provisional reference index was calculated with the following formulas. First, the transition rate of radioactive substances from raw logs / mushroom bed into Shiitake was estimated by measuring the radioactive substances detected from raw logs, mushroom bed and Shiitake grown on them. Then the provisional reference index for raw logs / mushroom bed was calculated by dividing the transition rate into the new standard limit for general foods.

 

Provisional reference indices are as below:

  • Raw logs to cultivate mushrooms, whether or not inoculated with mycelium: 50Bq/kg
  • Growth substrate to cultivate mushrooms: 200Bq/kg 
     

Shiitake mushrooms cultivated on raw logs in open fields

Shiitake mushrooms cultivated on raw logs in facilities

Shiitake mushrooms cultivated on mushroom bed

 

 

 

 

 

 

 

 

 

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