Radiation exposure

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Natural and artificial radiation exposure

As radiation exposure or radiation exposure is defined as the action of ionizing radiation on living organisms or matter . In contrast to the term radiation exposure , radiation exposure presupposes a damaging effect in the usage of radiation protection .

Quantification of radiation exposure

The term radiation dose is used to quantify the radiation exposure of people .

The absorbed dose D ( SI unit of measurement Gy ) is the specific amount of energy that is absorbed by a certain amount of matter through absorption of the radiation . If an organ with a mass m T (SI unit kg ) absorbs a certain energy E (SI unit J ), the quotient is called the organ energy dose D T, R :

In order to express the effect of radiation on the human body, it is not sufficient to state the absorbed dose, since the different types of radiation have different biological effects with the same amount of energy in the body tissue. The biological effects are taken into account using radiation weighting factors. The product of the organ energy dose and the weighting factor is called the organ equivalent dose (formerly organ dose). The SI unit of measurement is the Sv . It should be noted that the weighting factors (e.g. for exposure to neutron radiation ) are not undisputed.

As a third step in this system, the different radiation sensitivity of organs and tissues must be taken into account. For example, human skin is less sensitive to radiation exposure than various internal organs. Therefore, the concept of the effective dose is introduced , in which organ- or tissue-specific factors take into account their sensitivities. The effective dose is the sum of the weighted organ equivalent doses of all individual organs and a measure of the risk caused by the radiation. The indication of a radiation dose without a precise description mostly refers to the effective dose. The occurrence of stochastic radiation damage is quantified with the effective dose .

Put simply, the effective dose is calculated from the absorbed dose absorbed by the body by weighting the biological hazard of the type of radiation and the sensitivity of the irradiated organs . This value can be used to estimate the consequences of radiation exposure.

Radiation exposure in Europe is recorded on the basis of Article 35 of the Euratom Treaty (EAGV) and Section 161 (1) of the Radiation Protection Act (StrlSchG) in Germany with the help of gamma local dose rate measuring networks. In Germany, the Federal Office for Radiation Protection operates the ODL measuring network with around 1,800 probes. The radiological hazard describes the assessment of the dangers of ionizing radiation .

Radiation exposure from natural sources

Average radiation exposure ( dose rate in µSv / h) outside of buildings in Germany, Austria, Liechtenstein and Switzerland. The map shows the surface geology: low values ​​in northern Germany, which was shaped by the Ice Age, medium and high values ​​in the low mountain ranges and in the alpine region, especially where crystalline basement rocks emerge.

The entire world and therefore people are constantly ionizing radiation exposure . The reason for this are natural radiation sources that have arisen and exist independently of humans. Cosmic radiation reaches the earth from space . Due to the protective atmosphere, the strength depends on the altitude. On average, the cosmic radiation on the ground leads to an effective dose of around 300  µSv per year. If you travel by airplane, the protective effect of the air envelope is reduced, depending on the altitude and the geographical latitude of the flight; inside an airplane at a height of 10 to 12 kilometers, a typical dose rate is 5 µSv per hour. On a flight from Frankfurt to Tokyo you are exposed to radiation exposure in the order of 60 µSv (when flying at low latitudes, for example over India) to over 100 µSv (when flying over the pole, where the earth's magnetic field is less protective). The population dose was estimated to be around 40 kSv / a (2000–2013). Because of the cosmic radiation (radiation), flying personnel is one of the professional groups with the highest mean radiation exposure. With an average of 2.35  millisievert effective dose per person, the mean radiation exposure in 2009 was 20 percent higher than in 2004. The range ranged from less than 0.2 millisievert to peak values ​​of seven millisievert per year. The cosmic radiation changed during an approximately eleven-year cycle with solar activity and increased significantly in the period from 2004 to 2009.

Another source of radiation are the natural radionuclides in soils and exposed rock , which is referred to as terrestrial radiation . The cause is primordial radionuclides, i.e. those that were formed before the formation of the solar system and are still present in significant quantities today due to their long half-life . In particular, plutonic rocks and especially granite , which emerges from a strongly differentiated magma , have significant contents of uranium and thorium .

The natural radionuclides get from the soil into water, plants and animals and thus into human food. All foods and water contain low concentrations of natural radionuclides. Most commonly, the radioactive element is 40 K . Every human being contains a certain amount of natural radionuclides. These are the cause of around 9,000 Becquerel  (Bq) activity in the average person's body.

Radon occupies a special position among natural radionuclides . 222 Rn is a radioactive noble gas that comes from the soil and occurs in low concentrations practically everywhere (see radon pollution ). It arises from the decay of uranium and itself breaks down into a number of other nuclides. In the open air it is quickly diluted, but in apartments it can accumulate to higher concentrations under certain circumstances, especially in some areas of Germany where special geological conditions exist. The average radon concentration in apartments in Germany is around 50 Bq / m³, in Austria 400 Bq / m³ is given as a guideline value (although the value is higher in many areas), and 200 Bq / m³ as a planning guideline value for new buildings (ÖNORM S5280-2,3 and Natural Radiation  Sources Ordinance NatStrV).

Overall, the effective human dose from natural sources is around 2.4 mSv per year, around half of which is caused by radon. However, the value fluctuates regionally and in Germany is between one and five millisieverts per year, in Austria the exposure to ionizing radiation is on average around 100 nSv / h (70–200 nSv / h, alarm level of the local dose rate is 300 nSv / h), the dose is about 1 mSv / year; including radon it is about 2.5 mSv / year. Within Europe there are doses of up to around 10 mSv per year. One of the highest levels of natural radiation in the world can be found in Ramsar, Iran, with an average annual effective dose of approx. 7 mSv and peak values ​​of up to 131 mSv.

Overview: cosmic rays

Increase in radiation exposure from cosmic radiation with altitude, decrease in the terrestrial portion
Height above the ground Effective dose per year
300 km ( outside the space shuttle ) 400–500 , 0mSv (in calm sun)
300 km ( space shuttle ) 100–200 , 0mSv (in calm sun)
010 km ( airplane - altitude) 000-040 , 0mSv (for permanent residence)
003800 m 000-001.8 mSv
003000 m 000-001 , 0mSv
002000 m 000-000.6 mSv cosmic + approx. 1 mSv terrestrial
000000 m 000-000.3 mSv cosmic + 0.5–2 mSv terrestrial
Estimated annual radiation exposure in space
Whereabouts in space Effective dose per year
interstellar ≈ 300-700 mSv
interplanetary ≈ 200 mSv (with calm sun)
moon ≈ 100 mSv (with calm sun)

Radiation exposure per year from components in space:

Radiation exposure from artificial sources

Imaging procedures in medicine

With the development of industry, research and medicine, humans have increasingly made radioactive substances and ionizing radiation usable. These are the cause of additional, so-called civilizing radiation exposure. The vast majority of this can be attributed to medicine, especially the diagnostic application of X-rays and nuclear medicine . Most examinations reveal doses that are comparable to those that humans have always ingested from natural radiation sources. Overall, the effective dose from medical applications averages around 1.9 mSv per year. Computed tomography has the highest share of medical radiation exposure . 6.1% of all medical recordings are from the computer tomograph, but the proportion of radiation exposure is 51.9%. Computed tomography of the abdominal cavity leads to single exposure doses of 10–25 mSv.

In a retrospective cohort study between January 1, 2005 and December 31, 2007, the cumulative effective radiation doses of 952,420 people between 18 and 64 years of age were calculated in the regions of Arizona, Dallas, Orlando, Florida and Wisconsin. During this period, 655,613 insured persons (68.8%) underwent at least one medical imaging procedure with radiation exposure. The mean cumulative effective dose from imaging was 2.4 ± 6.0 mSv per insured per year. A moderate effective dose between 3 and 20 mSv was exposed to 193.8 per 1000 insured persons and year. This corresponds to the order of magnitude that can be achieved for occupationally radiation-exposed persons in the health care and nuclear industry who are under constant control. However, this control does not take place in patients. High effective exposures between 20 and 50 mSv were calculated for 18.6 and very high exposures above 50 mSv for 1.9 per 1000 insured persons and year. In general, an increase in the radiation dose was observed with increasing age, with women being even more exposed than men. Computed tomography and nuclear medicine exams contributed 75.4% to the cumulative effective dose. 81.8% of the total radiation dose was applied during outpatient examinations.

With around 1.3 x-rays per inhabitant per year, Germany takes a top position. The medical application of ionizing radiation leads to an additional radiation exposure of roughly 2  mSv / a per inhabitant. Theoretically 1.5% of the annual cancer cases can be traced back to this.

Nuclear facilities

Another, albeit very small, part of civilization radiation exposure can be traced back to the normal operation of nuclear facilities , for example nuclear power plants . For technical reasons, when operating nuclear power plants, small amounts of radioactive substances enter the air via the chimney or are released into the environment via the cooling water. The resulting effective dose is on average below 10 µSv per year, that is, far below the natural radiation exposure. Nevertheless, according to a study, the results of which are confirmed by the Federal Office for Radiation Protection , in the vicinity of German nuclear power plants (within a radius of 5 km), leukemia diseases are observed more frequently in children under the age of 5 than the statistical mean. Due to the low level of radioactive emissions from power reactors (factor 1,000 too low), the finding cannot be explained with the power reactors as the sole cause. Further investigations are necessary to explain the cause of this connection.

Researchers at the International Agency for Research on Cancer analyzed data from 268,000 male and 40,000 female nuclear workers from France, the UK and the US. Their health had been monitored in a cohort study for an average of 27 years . The personal dose averaged 1.74 millisieverts annually , from which mean organ doses for the red bone marrow of 1.1 millisievert per year and 16 millisievert for professional life were estimated. According to the study, the risk of dying of leukemia increased for the affected group of people by almost five percent compared to the risk of people not exposed to radiation ( relative risk 1.05).

The burdens in serious accidents can be significantly greater. For the first year after the Chernobyl accident , an additional average effective dose of 1.0 mSv in Bavaria and 0.1 mSv in North Rhine-Westphalia was calculated. The current additional radiation exposure in Germany due to the reactor accident is still approx. 16 µSv / a.

Coal production and use

Going from nuclear accidents apart (the hitherto most momentous 1986 in Chernobyl contaminated large parts of Europe), the radiation exposure of people by promoting and burning is coal significantly higher than that from nuclear power plants. Coal in all deposits contains traces of various radioactive substances, especially radon , uranium and thorium . When coal is extracted, especially from open-cast mines , through exhaust gases from power stations or through the power station ash , these substances are released and contribute to artificial radiation exposure through their exposure path . The binding to fine dust particles is particularly critical. In the vicinity of coal-fired power plants , higher loads are sometimes measured than in the vicinity of nuclear power plants. The coal used annually worldwide for power generation alone contains around 10,000 t of uranium and 25,000 t of thorium. According to estimates by the Oak Ridge National Laboratory , the use of coal from 1940 to 2040 will release 800,000 tons of uranium and 2 million tons of thorium worldwide.

Extraction of oil and gas

see radioactive waste # Disposal without precise evidence

Electrotechnical sources

In addition to low-frequency electromagnetic radiation (see electromagnetic environmental compatibility ), electrical engineering systems can also emit ionizing radiation. Until the 1980s, the protection and protective regulations against X-rays from military radar devices were inadequate (see Damage to health from military radar systems ).

Other technical sources

At around 5 µSv (in Germany), nuclear weapon tests are no longer significant. In the 1960s, on the other hand, radiation exposure for Central Europeans was higher than after the Chernobyl accident.

Ionizing particles ( oil drilling technology for exploration and compact emitters for material measurements) are used in technical measuring systems . Their handling generates radioactive waste which, if uncontrolled disposal or landfilling, endangers or poisons the environment . Well-known trivial examples are the previously common dials of wristwatches with luminous paint , which was stimulated by the addition of radium , the starters of energy-saving fluorescent lamps and the sensors of smoke detectors . Furthermore, beta emitters have recently been used in some measuring devices for fine dust .

Radiation exposure through food and luxury foods

Game and wild mushrooms

Significant radiation exposure can occur through the food chain. After the Chernobyl reactor accident, for example, large quantities of 137 Cs were precipitated in some districts of Bavaria by heavy rain. While arable soil is hardly contaminated, the 137 Cs remains in the upper layers of the forest floor and can cause considerable contamination of mushrooms and game . The highest value measured in wild mushrooms in 2008 by the Bavarian State Office for Health and Food Safety was 10,484 Bq / kg. In 2009 the peak value was 8,492 Bq / kg and in the period from May to December 2010 values ​​of more than 1,000 Bq / kg were determined in four samples. Wild boars are much more exposed to deer than deer because they find their food in the litter layer of the forest floor, there in particular in truffles, which can specifically enrich cesium. The highest value measured in a sample of wild boar meat in Bavaria in 2008 was 7,604 Bq / kg, the average of all samples was 707 Bq / kg, and thus well above the maximum limit of 600 Bq / kg set for the marketability of the meat. In 2013, individual samples of wild boar meat were even contaminated with over 10,000 Bq / kg. Oral intake of 1000 Bq 137 Cs causes exposure to 14 µSv (for limit values ​​see Sievert unit ).

tobacco

Tobacco is another source of radiation. The smoking of 20 daily cigarettes leads according to various studies on an average annual radiation exposure at a level from 0.29 to 13 mSv by 210 Po and radioactive lead ( 210 Pb). Other sources speak of a total radiation exposure of 70 µSv per cigarette in the particle phase. Between 40% and 70% of this is retained in the filter.

Protection against ionizing radiation

Since the effects are based on purely statistical values, it is difficult to set limit values ​​for the normal population. In practice, this is based on the fluctuation range of natural radiation exposure.

For the protection of the population and the environment against radiation from the targeted use of radioactivity , the following limit value ( effective dose ) is specified in the European Directive 96/29 / EURATOM and the German , Austrian and Swiss Radiation Protection Ordinance (StrlSchV):

  • 1 mSv per year for people in the general population (this should also cover segments that are particularly sensitive to radiation, such as germinating life or children).

For persons of legal age (with the exception of pregnant women) who are occupationally exposed to radiation, the above Legal norms the following limit values ​​(effective dose):

  • 20 mSv per year
  • 50 mSv in one year, but not more than 100 mSv in 5 years.

There are also limit values ​​for certain organ doses. In exceptional cases, exceedances are also permitted.

According to the German and Austrian Radiation Protection Ordinance, occupationally exposed persons are divided into two categories:

  • Category A persons: They may achieve a maximum annual dose of over 6 mSv, but must undergo annual medical examinations (in Germany only for work in the controlled area). It's I. d. As a rule, the group of people who regularly stay in controlled areas.
  • Category B persons: Occupationally exposed persons who cannot be assumed to receive more than 6 mSv within 12 months. In Austria they must also be continuously dosed while working in the radiation area; in Germany this applies i. General only for people who are in the controlled area.

However, limit values ​​that are set for emergency services are also important, as these naturally have to be higher when it comes to saving human life or special property. In Austria, for example, the following limit values ​​have been set for emergency personnel in the event of personal danger and assistance. a. taken over by the Austrian Federal Fire Brigade Association :

  • 15 mSv in normal fire service (operational dose )
  • 100 mSv for saving people  - this value may be recorded once a year ( life-saving dose )
  • 250 mSv in the event of a disaster, this may only be taken once in a lifetime ( disaster dose ).

The same values ​​have found their way into Germany as “dose guide values” in the fire service regulation FwDV 500 “Units in NBC operations”.

The working life dose for persons exposed to radiation should not exceed 0.4 Sv, for astronauts 1–4 Sv.

Tables

The following table shows the type and extent of various types of radiation exposure. The figures given are mean values. Deviations up and down are possible depending on the place of residence and activity. For the Federal Republic of Germany these values ​​are published in an annual parliamentary report, in Austria by the Federal Ministry of Agriculture, Forestry, Environment and Water Management (BMLFUW) together with the Federal Ministry of Health (BMG), in Switzerland by the Federal Office for Civil Protection (BABS) within of the Federal Department of Defense, Civil Protection and Sport (DDPS), in Slovenia by the Slovenian Nuclear Safety Administration (SNSA), an agency of the Ministrstvo za okolje in prostor (MOP, the Ministry of Environment and Spatial Planning).

Effective doses of the radiation sources in mSv / a

Type of radiation source DE AT
Natural sources of radiation
Cosmic rays (m) 0.300 1.00
Terrestrial radiation
• External radiation 0.400
• Inhalation of radon (and its derivatives) 1.100 1.60
• Other internal radiation (ingestion of natural radionuclides) 0.300 0.30
Sum of natural radiation sources ≈ 2, 000 ≈ 3, 00
Artificial radiation sources
Medical applications 1.900 1.30
Nuclear power plants (normal operation) <0.010 -
Consequences of the Chernobyl accident (t) <0.011 <0.01
Nuclear bomb tests / nuclear weapons tests <0.010
Other artificial radiation <0.020
• App. Radioact. Fabrics and ion. St. in research technology, household <0.020
• Occupational radiation exposure approx. 0.050
Sum of artificial radiation sources ≈ 2, 000 <1.50
Sum of natural + artificial radiation sources ≈ 4, 000 ≈ 4.30
(m) at sea level
(t) Level 25 years after the accident

Examples of cans

Examples of cans
Type of exposure dose
Focus dose (target tissue)
(data in mGy )
Radiation therapy for cancer 020,000- 080,000
Radioiodine therapy for benign diseases 120,000-400,000
Equivalent dose (whole body)
(data in mSv )
Threshold dose for acute radiation damage 250
Computed tomography (chest) 006-8
Airplane trip (8 h, altitude 12 km) 000.04-0.1
X-ray (skull) 000.1

See also

literature

Germany
Austria
  • Federal Ministry of Agriculture, Forestry, Environment and Water Management - Section V, Federal Ministry of Health - Section III: Radioactivity and Radiation in Austria. Data and evaluation. Annual report 2007–2008 , Vienna July 2011.

Literature specifically:

Web links

Wiktionary: Radiation exposure  - explanations of meanings, word origins, synonyms, translations

Country-specific:

Individual evidence

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  2. ↑ nirs.go.jp ( Memento of the original from September 20, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English) @1@ 2Template: Webachiv / IABot / www.nirs.go.jp
  3. ^ Alvarez LE, Eastham SD, Barrett SR: Radiation dose to the global flying population. J. Radiol. Prot. 36 (2016) 93-103. PMID 26769857 doi: 10.1088 / 0952-4746 / 36/1/93
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  20. ^ BUND Landesverband Nordrhein-Westfalen eV (Ed.): Fine dust and radioactivity from opencast mines. Current interim results (= BUNDaktuell April 2004). Bund für Umwelt und Naturschutz Deutschland Landesverband Nordrhein-Westfalen eV, Düsseldorf 2004 Online PDF 697 kB, accessed on September 2, 2013
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  22. ↑ What is particulate matter? (PDF; 357 kB) RWE , accessed on December 12, 2017 .
  23. ↑ Bavarian State Office for Health and Food Safety: Radiocesium in Waldpilzen - Study results 2008 online , accessed on September 2, 2013.
  24. ^ Bavarian State Office for Health and Food Safety: Radiocäsium in Waldpilzen - Test results 2009 online , accessed on September 2, 2013.
  25. ↑ Bavarian State Office for Health and Food Safety: Investigation of radiocesium contamination in wild mushrooms from Bavaria from May to December 2010 online , accessed on September 2, 2013.
  26. ↑ Bavarian State Office for Health and Food Safety: Radiocesium in indigenous venison - test results 2008 online , accessed on September 2, 2013.
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  30. ↑ Federal Office of Public Health (Switzerland): Radioactivity and Radiation Protection , 1999, p. 15.