Every year there are fewer artificial radioactive substances in the environment
There are still radioactive substances in nature in Finland that originate from the Chernobyl nuclear power plant accident. The annual report on Environmental Radiation Monitoring in Finland by the Radiation and Nuclear Safety Authority details radioactive substances found in nature last year that do not originally belong in nature and how much of them there are in the environment.
The Radiation and Nuclear Safety Authority’s (STUK) environmental monitoring programme is designed so that even minor changes in radioactivity in the environment can be detected and reacted to, if necessary. Because there is radiation everywhere, STUK also finds it everywhere. Accurate measurement methods and a well-designed environmental radiation monitoring programme provide a reliable overview of radioactivity in the Finnish environment.
The measurement results show that no emissions of radioactive substances with harmful effects on human health or the environment occurred in Finland last year.
The radiation exposure to Finns caused by artificial radioactive substances in the environment in 2023 was less than 0.02 millisieverts (mSv), which is very low compared to Finns’ average annual radiation dose of 5.9 mSv. The majority of Finns’ radiation exposure comes from radon in the indoor air, i.e. from natural radioactivity.
Chernobyl caesium still found
The only significant sources of artificial radioactive substances are decades old. Radioactivity from atmospheric nuclear weapons experiments in the 1950s and 1960s along with the Chernobyl nuclear accident in 1986 is still measured in environmental samples, albeit less and less every year.
In three forest fungus samples measured by STUK last autumn, the concentration of radioactive caesium 137 exceeded the limit value of 600 becquerel per kilogramme. Foodstuffs above this limit should not be sold according to EU recommendations. However, despite exceeding the limit value, the concentrations measured for mushrooms are so low that by eating them it is impossible to ingest an amount of radioactive substances that is hazardous to health. If desired, the radioactivity of the mushrooms can also be reduced by boiling, freezing or soaking.
Online monitoring and laboratory measurements
STUK’s external radiation monitoring network provides real-time information on the radiation situation throughout Finland. There are 255 measurement stations in total. STUK also has stations at eight locations where radioactive substances are collected from outdoor air and as particles or deposition that falls to the ground with rain.
STUK monitors the radioactivity of lakes, rivers and the Baltic Sea by measuring water samples in its laboratory. STUK’s laboratories in Jokiniemi, Vantaa, also process other environmental samples, such as milk obtained from dairies, foodstuffs purchased from shops, domestic water samples collected from all over Finland as well as berries, mushrooms, fish and game from the Finnish nature.
As part of environmental radioactivity monitoring, STUK measures the amount of radioactive substances in people every year in Helsinki, Tampere and Rovaniemi. The substances enter peoples' bodies through inhalation or food. These radioactive substances are detected by directly measuring the radiation they emit. STUK carries out the population measurements in a mobile laboratory built into a lorry.
Information on the environmental radiation situation
Environmental Radiation Monitoring in Finland: Annual report 2023
STUK's Environmental radiation website
Radiation today
Radioactivity in outdoor air
