Radionuclides

Radioactivity in food

The legislative framework

Natural levels of radioactivity in food are extremely low and under normal circumstances there is no specific legislation prescribing maximum limits for radionuclides in food. The situation changes if there is a nuclear accident or other radiological emergency, as is the case following the March 2011 accident at the Fukushima Daiichi plant in Japan. If there is evidence of food contamination following a nuclear accident or emergency, Council Regulation (Euratom) 3954/87 becomes active. This Regulation requires the European Commission to take certain prescribed steps to protect the health of consumer. The first step is to issue a "special conditions" Regulation that fixes maximum permitted levels of radionuclides in foods.

The Regulation will adopt the limits for seafood set out in Council Regulation (Euratom) 3954/87, and are the following:

	Maximum permitted level (Bq/kg)
Isotopes of strontium, notably Sr-90	750
Isotopes of iodine, notably I-131	2000
Alpha-emitting isotopes of plutonium and transplutonium elements,  notably Pu-239, Am-241	80
All other nuclides of half-life greater than 10 days, notably Cs-134 and Cs-137	1250

The Commission then consults with experts and, preferably within a month of adopting the special conditions Regulation, brings out a second Regulation either confirming or adapting the provisions of the first Regulation.

In addition to Council Regulation (Euratom) 3954/87, there are 2 other Regulations that refer to radioactive contamination of foods:

• Regulation 2219/89 lays down the conditions for exporting food and feed after a nuclear accident or radiological emergency. Food and feed with levels of radioactive contamination that exceeds permitted levels may not be exported from member states.
• Regulation 737/90 applies to agricultural products originating in third countries that are affected by the Chernobyl accident.

 

Legislation in force following the Fukushima accident

Shortly after the Fukushima nuclear accident, the European Commission adopted Commission Regulation (EU) No 297/2011 imposing special conditions governing the import of feed and food originating in or consigned from Japan following the accident at the Fukushima nuclear power station. This Regulation specified the conditions under which food from Japan may be imported into the European Union. It was amended several times before being repealed and replaced by the Regulation currently in force, which is Commission Implementing Regulation (EU) 284/2012.

The limits for seafood affected by the Fukushima accident as set out in Commission Implementing Regulation (EU) No 284/2012 are the following:

	Maximum permitted level (Bq/kg)
Sum of caesium-134 and caesium-137	100

The value in the table is equivalent to the maximum level set in Japan, and is more stringent than the levels set in Council Regulation (Euratom) 3954/87.

The European Commission has recommended that Member States take random samples of imported migratory pelagic fish originating in FAO Major Fishing Area 61 and test them for caesium-134 and caesium-137. Results of testing are available here.

 

Monitoring radioactivity in the UK

The major producers of radioactive waste in the UK are required to monitor the environment around their premises. The Envoronment Agency, the Food Standards Agency, the Northern Ireland Environment Agency and the Scottish Environment Protection Agency work together on monitoring programmes to measure radioactivity in the environment and in food. Their results are brought together annually in the Radioactivity in Food and the Environment (RIFE) report. The risk to public health of any radioactivity detected is assessed in the report.

 

How safe are the limits?

The levels set in Regulation 3954/87 are based on the following assumption: A person consuming a diet containing 10% of food contaminated at the maximum level will, over one year, receive a dose of ionising radiation of 1 millisievert (mSv). 1 mSv corresponds to the acceptable annual dose limit for a human being; the potential dose of 1mSv from the diet will be in addition to any other ionising radiation, natural or otherwise, received by that person.

 

Notes on the units used to describe radioactivity

The limits are set in Bq/kg (becquerel per kilogram). A becquerel is an amount of radiation emitted equal to the number of disintegrations per second the radionuclide undergoes. Roughly speaking, the more becquerels, the more the harmful radiation, but this may be misleading, because there are different types of radiation (alpha, beta, gamma and neutron radiation), each with its own adverse health effect. In addition, the health effect depends on prameters such as the food, its consumption and the age of the consumer.

One millisievert (1 mSv) corresponds to the acceptable annual dose limit for a human being. The sievert is a derived unit that describes a dose of radiation in terms of the biological effect that it has on the human body. The definition of the sievert depends on the relationship between the radiation and the effect on the human body, and is determined by the International Commission on Radiological Protection. 

 

Further information

See the Food Standards Agency's Radioactivity in food: your questions answered: http://www.food.gov.uk/safereating/rad_in_food/radioactivity/

Radioactivity in Food and the Environment (RIFE): http://www.food.gov.uk/science/surveillance/radiosurv/rife/