Monitoring of environmental radiation
The purpose of the surveillance of environmental radiation is to assess the radiation safety of the Finnish environment. The concept of environment refers to factors that are present in the natural or built environment and with which humans have an interactive relationship. In Finland, the Radiation and Nuclear Safety Authority (STUK) is responsible for nationwide environmental radiation control.
STUK’s regulatory responsibility is based on the Decree on the Radiation and Nuclear Safety Authority and the Radiation Decree. In addition, the European Union Member States are obliged under the Euratom Treaty to continuously monitor the levels of radioactivity in the air, water and soil. Together with STUK, the Finnish Meteorological Institute and the Finnish Defence Forces carry out radioactivity surveillance at their own observation stations.
Environmental safety assessment is part of environmental risk management. The objective of safety assessment is to protect people, the environment, society and future generations from the harmful effects of radiation. In order to achieve this goal, it is essential to be constantly aware of the levels of radiation exposure of people and the environment. At the same time, compliance with the radiation legislation is ensured. Furthermore, radiation surveillance is designed so that it is possible to detect changes in radioactivity levels in the environment and respond to them, estimate radiation doses received by people and plan and inform about realistically available means to reduce or avoid exposure.
Radioactive materials occur naturally in the Finnish environment and they are unevenly distributed. This means that naturally occurring radioactive materials are present in different amounts in different areas everywhere in our living environment. From the human perspective, the most significant substances include radon (present in indoor air), uranium (present in soil) and decay products of uranium (present in food and drinking water). Artificial radioactive materials have spread into the environment as a result of nuclear weapon tests performed in the atmosphere, nuclear power plant accidents and various other accidents. Small amounts of radioactive substances are continuously released into the environment from nuclear power plants and as a result of other uses of radiation.
The surveillance of environmental radiation consists of a regular annual programme carried out each year, thematic investigations carried out every five to ten years, and surveillance of radiation around nuclear power plants and mines. The surveillance programme covers all significant exposure routes and includes the monitoring of radioactivity levels in the human body.
Finns are exposed to ionising radiation originating from both natural and artificial sources. The average annual radiation dose (effective radiation dose) received by Finns is 5.9 millisieverts (mSv). More than half of this (4 mSv) comes from radon present in indoor air. Approximately one fifth of the annual radiation dose received by Finns (1.1 mSv) is caused by other natural radiation. All in all, radiation exposure caused by artificial radioactive substances in the environment is negligible when compared to the overall radiation exposure.