- 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
- Applications in daily life and in technology
- Radioactive radiation sources in Germany
- Register high-level radioactive radiation sources
- Type approval procedure pursuant to RöV and StrlSchV
- Cabin luggage security checks
- Radioactive materials in watches
- Ionisation smoke detectors (ISM)
- What are the effects of radiation?
- Acute radiation damage
- 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 informations
- Occupational radiation protection
- Nuclear accident management
- What happens in an emergency?
- Federal and state tasks
- In the event of an emergency
- Measuring networks
- Exercises for emergency situations
- Nuclear accidents
- 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
- Laws and regulations
- BfS Topics in the Bundestag
Biological Dosimetry at the BfS
In the cytogenetic laboratory of the BfS in Neuherberg, dose estimations can be carried out on over-exposed or presumably over-exposed persons using biological indicators.
Method: chromosome aberration analysis in lymphocytes of peripheral blood
The method used is a chromosome aberration analysis in lymphocytes of peripheral blood. In many studies, the dicentric chromosome has proven to be the most reliable and sensitive biological indicator of exposure to ionising radiation. Because of its low spontaneous frequency, and because it is characteristic for ionising radiation, the dicentric chromosome is the most suitable indicator of a recent radiation exposure. The detection limit for homogenous whole-body exposure is 0.1 gray (Gy) for sparsely ionising radiation.
At the BfS, there are dose-effect curves for different radiation qualities established. From extensive investigations on healthy persons not exposed to radiation, there is a comprehensive control group available for the spontaneous frequency of various chromosome aberrations.
To prove acute radiation exposure, the frequency of dicentric chromosomes is routinely determined and a dose estimation is assessed using the calibration curves if a statistically secure (significant) increase of cytogenetic damage is ascertained in comparison to spontaneous frequency.
Reasons for chromosome analysis
Reasons for chromosome analysis include:
- radiation exposure or suspected radiation exposure when no physical dosimeter was carried,
- during monitoring it was estimated that the whole-body dose of 100 millisieverts (0.1 sievert) has been exceeded,
- discrepancies occured in the evaluation of physical radiation protection monitoring and an independent source of information is required,
The analysis process
Before a blood sample is taken, the BfS has to be contacted to discuss in advance the presumed radiation exposure and to ascertain whether a chromosome analysis for the purpose of dose estimation is feasible. If so, the Federal Office for Radiation Protection will send to the person or the attending physician a blood collection system together with a questionnaire which includes questions about the person and the circumstances of the accident.
After blood withdrawal and dispatch of the blood sample, employees in the laboratory prepare blood cultures. After two days, chromosome preparations are made from the lymphocytes of the blood cultures. Alternatively, micronuclei preparations can be performed after 3 days.
Subsequently, the structure and shape of the chromosomes are analysed or the micronuclei are recorded. Employees investigate how frequently dicentric chromosomes appear or determine the number of micronuclei. In case of an exposure dating back some time, they record the number of symmetrical translocations. Using the corresponding dose-effect curve, they estimate the dose, if there is a clearly noticeable (statistically significant) increase in chromosome damage.
Costs of chromosome analysis
Depending on time and effort needed for the respective analysis, chromosome analyses may be subject to charges. Remuneration for the service performed is invoked by contract. The federal states may make use of the service free of charge.
State of 2018.02.26