- What are electromagnetic fields?
- Static and low-frequency fields
- What are static and low-frequency electric and magnetic fields?
- Direct and alternating voltage
- Effects of static and low-frequency fields
- Reports & Evaluations
- Radiation protection relating to the expansion of the national grid
- Basics transfer of electrical power
- High-frequency fields
- What are high-frequency fields?
- Applications high-frequency fields
- Radiation protection in mobile communication
- What is mobile communication?
- Reports and evaluations
- What is optical radiation?
- UV radiation
- What is UV radiation?
- Sun but safe!
- Effects of UV radiation
- Protection against UV radiation
- UV index
- Infrared radiation
- What is ionising radiation?
- Radioactivity in the environment
- Where does radioactivity occur in the environment?
- What is the level of natural radiation exposure in Germany?
- Air, soil and water
- Building materials
- Industrial residues (NORM)
- BfS laboratories
- Applications in medicine
- Radiation protection in medicine: international activities
- Applications in daily life and in technology
- Radioactive radiation sources in Germany
- Register high-level radioactive radiation sources
- Type approval procedure
- Cabin luggage security checks
- Radioactive materials in watches
- Ionisation smoke detectors (ISM)
- What are the effects of radiation?
- Effects of selected radioactive materials
- Consequences of a radiation accident
- Cancer and leukaemia
- Genetic radiation effects
- Individual radiosensitivity
- Epidemiology of radiation-induced diseases
- Ionising radiation: positive effects?
- Risk estimation and assessment
- Radiation protection
- Basic information
- Occupational radiation protection
- Nuclear accident management
- What is an emergency?
- What happens in an emergency?
- Federal and state tasks
- In the event of an emergency
- Measuring networks
- Exercises for emergency situations
- Defence against nuclear hazards
- Service offers
- Radon measurements
- Incorporation monitoring
- Biological dosimetry
- Online library
- About us
- Science and research
- Research concept
- Scientific collaborations
- EU research framework programme
- BfS research programme
- Third-party funded research
- Departmental research
- Selected research projects
- Selected research results
- Professional opinions
- Science Council
- Laws and regulations
- BfS Topics in the Bundestag
What are the effects of radiation?
When ionising radiation hits a cell, the radiation energy is taken up (absorbed) by the molecules of the cell. This energy has the effect of ejecting electrons from the molecules (ionisation) or breaking bonds in the molecules. The resulting molecule types (radicals) are very reactive chemically and can be electrically charged or electrically neutral. These radicals react with the other molecules inside the cell which may then directly or indirectly lead to cell damage. In most cases, water molecules are affected. However, other substances inside the cell can be affected as well, such as proteins or the DNA (carrier molecules of genetic information).
For the long-term effects on the organism the alterations of the DNA are particularly important.
The effects of radiation on the cell
In general, the cell is able to repair radiation damage which means that no biological effects can be observed. However, if the cell is unable to repair the damage, it usually dies by targeted programmed cell death (apoptosis). In the case of severe damage caused by radiation exposure with very high radiation doses, the cell dies uncontrolled (necrosis). If a faulty or insufficient repair occurs, genetically altered (mutated) cells, which are also able to replicate, may develop.
The effects of radiation on the organism
If and to what extent the radiation exposure leads to health damage depends on the radiation dose absorbed, the type of radiation and the mainly affected organ or body tissue. Radiation damage may also be caused by ionising radiation from natural sources (such as radon).
As a reference: For people living in Germany the dose from natural sources is about 2 to 3 millisieverts per year on average.
Deterministic radiation damageshow / hide
Damage in tissue caused by ionising radiation is referred to as deterministic radiation damage. The severity of the damage increases with increasing dose. Generally there is a threshold dose value above which damage occurs. Examples for deterministic effects are skin erythema and epilation.
Radiation doses exceeding a certain threshold can cause specific tissue reactions in the human body, also called deterministic radiation damage. The typical threshold value is about 500 millisieverts (mSv). Deterministic effects are the result of a massive cell killing and the subsequent loss of function of the affected organs or tissues. Particularly affected are
- the skin,
- the hair, and
- the gastrointestinal epithelium
Above the dose-threshold, the severity of the injury increases with dose and the damage appears earlier after higher doses. Radiation below the threshold dose causes no deterministic effects. Stochastic effects, which occur later on can, however, not be excluded.
Acute radiation injuries
- erythema (skin redness, phenomena resembling burns),
- hair loss,
- fertility impairment, and
Late deterministic effects
There are some late deterministic effects like pulmonary fibrosis (increase in fibrous connective tissue leading to loss of pulmonary function). It appears 6 to 24 months after exposure.
Stochastic radiation damageshow / hide
Changes in the genetic material of cells (DNA) caused by ionising radiation are referred to as stochastic radiation damage. They occur only with a certain probability. The probability of a damage depends on the dose, whereas the severity of damage is not affected by the dose. Cancer and leukaemia are examples for stochastic damage.
Development of stochastic radiation damage
The genetic information of a cell can be altered by a faulty or insufficient repair of the DNA. During the natural process of cell division the altered (mutated) cells replicate. In the case of somatic cells, this procedure can lead to the development of cancer, years after the exposure. The occurrence of radiation-induced hereditary defects has not been observed in humans until now, yet they have been demonstrated in animal studies.
Altering the genetic information in the germ cells produced in the testicles or ovaries can result in hereditary defects in the following generations. The term used with somatic cells as well as germ cells is stochastic radiation damage. It may also occur with low doses of ionising radiation. This means that both low and high doses may induce stochastic damage, but it does not necessarily have to occur. The probability that this type of radiation damage will occur increases, however, with increasing radiation exposure. Between the radiation exposure and the onset of the disease a long period of time may pass (so-called latency period).
|Deterministic Radiation Effects||Stochastic Radiation Effects|
|Description||Damage to tissues and organs, mostly occurring immediately||Delayed damage due to cells with damaged DNA (genetic material)|
|Cause of the Damage||Killing or dysfunction of numerous cells||Mutations and subsequent replication of individual mutated cells (somatic cells or germ cells)|
|Dose Dependence||The higher the radiation dose, the more severe the radiation damage||The higher the radiation dose, the higher the probability of radiation damage occurrence|
|Dose Threshold Value||About 500 millisieverts (mSv);|
for the unborn child about 50 to 100 mSv
|Examples||Skin reddening, hair loss,|
infertility, acute radiation syndrome, malformations and brain maldevelopments in the unborn child
|Cancer, leukaemia, hereditary effects|
Objectives of radiation protection
Radiation protection is aimed at protecting human health. Its objective is to avoid deterministic radiation effects in a reliable manner and to reduce the risk for stochastic effects to a reasonably attainable level.
State of 2018.07.09