Low radioactive concentrations in grain

Low radioactive concentrations in grain

Radiation dose received from grain is low. Most of the radiation dose resulting from grain consumption is caused by radioactive substances naturally occurring in soil.

Today, radioactive substances in domestic grain expose consumers to a small annual average radiation dose of 0.03 millisieverts. The average radiation dose received by Finns from all sources combined is 3.2 millisieverts per year.

The majority of the dose resulting from grain consumption is due to the lead-210, polonium-210, radium-226 and radium-228 isotopes, each of them radioactive substances that are naturally present in soil. The proportion of natural uranium and thorium is very low, approximately one thousandth of the radiation dose caused by radioactive substances in grain.

Many naturally occurring radioactive materials are formed from uranium and thorium present in the earth’s crust. When decaying, they produce other radioactive substances, such as radon, lead-210 and polonium-210 isotopes and radium. From the earth’s crust, they find their way into plants, ground water, air, etc.

Typical activity levels of naturally occurring radioactive materials


2 mBq per kilogram


100 mBq per kilogram

radium-228 and


200 mBq per kilogram


In farm produce, artificial radioactive substance concentrations are very low.  Artificial radioactive materials found in Finland mainly originate from nuclear weapon tests carried out in the 1960s and the Chernobyl nuclear power plant accident in 1986. Cesium-137 and strontium-90, originating from nuclear fallout, account for less than one per cent of the radiation dose caused by radioactive materials in grain, while in the 1960s their proportion was approximately 50 per cent.

The average cesium-137 concentration in farm produce is less than one becquerel per kilogram.

The majority of radioactive materials in grain come from the nature.