- Natural sources of radiation include cosmic radiation, gamma radiation prevailing at ground level, decay products of radon in the air and various radionuclides found naturally in food and drink.
- Artificial sources of radiation include medical X radiation, radioactive waste caused by testing nuclear weapons in the atmosphere and the emission of radioactive waste from the nuclear industry.
Ionising radiation is imperceptible and measuring the level of radiation is only possible using a special measuring device.
Radioactive substance emits ionising radiation creating ion-pairs in tissues meaning that some part of the molecules brake down into electrically charged particles. The spontaneous fissile ability of atomic nuclei is called radioactivity and the respective atomic nuclei are called radionuclides.
The released particles and gamma-quanta are capable of ionising the surrounding substance. That is why the flow of released particles and gamma-quanta is called ionising radiation.
Ionising radiation may be natural, for example, radioactive gas radon found in the ground emits alpha radiation. In processing X-ray images, however, artificially created X-rays are used.
For living tissues, the most dangerous radiation is ionising radiation because its qualities are most hazardous to human tissue, causing diseases such as cancer.
In Estonia, information on the radioactivity levels in the environment is collected through the annual national radiation monitoring program. Every year, more than 250 collections of environmental samples are examined. The main focus is on the radionuclides emitted into the environment by human activity.
Estonia does not have any nuclear power plants, meaning that the main threat is pollution coming from outside the border. The general gammadose rate in the atmosphere is monitored in real-time in 10 monitoring stations across Estonia and the radioactivity of airborne particles in 3 filtering stations.
Approximately half of the radiation dose affecting the residents is caused by radioactive gas radon which is found in the earth’s crust. Radon occurs naturally upon the decay of uranium. Uranium can be found more or less everywhere in the earth’s crust Therefore radon can also be found everywhere. High level of radon found in soil is connected with the Dictyonema argillite crops (Northern Estonia) and the coverage of moraine rich in granite (Southern Estonia).
Protecting a person from excessive radiation is essential. A person is subject to radiation as many times as necessary and as rarely as possible.
Radiation-related activity is based on the radiation practice license and all exposed workers must have required qualification. The latter is necessary to inspect the radiation caused by medical treatment, the radioactive substances in food products as well as contact with radiation apparatuses and sources.
Regulation of the radiation sector
The main act used by the Government and the Minister of the Environment as reference is the Radiation Act.
Radiation safety is organised by the Ministry of the Environment through the Environmental Board and the Environmental Inspectorate.
- The Ministry of the Environment develops radiation policies and legislative drafting.
- The Environmental Board issues radiation practice licenses, conducts radiation monitoring, manages the emergency notification or early warning system and is responsible for monitoring nuclear practices.
Approximately half of the person’s exposure dose is caused by radioactive gas coming from the ground – radon.
Radon and its daughter radionuclides as well as additional natural exposures significantly increase the risk of developing malignant tumours, primarily lung cancer.
Radon is formed by natural decay of uranium. Uranium is found in a greater or lesser extent throughout the earth’s crust. Thus, radon can also be found everywhere.
The high levels of radon may be found almost everywhere in Estonia. Radon danger is mostly present in North Estonia, where porous and fractured limestone lies on the graptolitic argillite rich in uranium.
Radon that is generated from the decay of uranium will be free to rise to the surface in such cases. Radon danger is also present in certain areas in Lääne-Virumaa and Tartumaa, where high radon concentrations are caused by the ice age sediments carried here from Scandinavia.
Radon enters the house due to cracks caused by the poor quality of construction and in case of the ageing of the building. Inhalation of radon-rich air increases the risk of lung cancer. Therefore, it is extremely important to protect yourself from excessive radiation exposure caused by radon.
Groundwater and domestic building materials have generally low radon content.
Radiation practice is any activity which increases or may increase the exposure of people to radiation emanating from artificial or natural sources of radiation.
Radiation practices inter alia include:
production, processing, use, possession, holding, storage, transportation, including import and export, and intermediate storage or final disposal of radioactive substances;
use of any electrical equipment emitting ionizing radiation and operating at a potential difference of more than 5 kilovolts;
operation of nuclear facilities.
Radiation practice licence is issued by the Environmental Board. More information can be found on their homepage.
Any activity after the discovery of a radiation source depends on the type of detected radiation source.
If 99% of people can identify an explosive in case they find it and act accordingly (they do not touch it, move away, call an emergency number), then it is difficult to identify whether the risk exists in terms of a radiation source and in most cases, it is only possible by means of the radiological label or special measuring instruments.
If the source is detected without shielding, with shielding or an empty shielding container, one must immediately leave the detection site.
Then, it is vital to immediately notify:
- the Rescue Board (telephone 112), or
- the Radiation Department of the Environmental Board (telephone (+372) 6644 900).
This is necessary, because the radiation source can be harmful to both humans and the environment.
Broken radiation source may cause pollution to spread on a wider area until it is defused, therefore, it is essential to defuse as quickly as possible. If the location of the source is difficult to be detected, it must be distinctively marked.
The information provided to the Rescue Board, the Environmental Inspectorate or the Environmental Board must be clear and unambiguous:
- source location (settlement name closest to the source location);
- which signs the assumption is based on that it is a radiation source;
- name and contact details of the person who called.
Last updated: 13.07.2021