Why is radiation as a cancer risk? How much radiation exposure in Germany is actually? Of what can you protect yourself What are not you? The Cancer Information Service has compiled facts and names of contact.
Radioactivity or radiation: what is it?
Referred to as radioactive decay products, the atomic nuclei, releasing energy in the form of radiation. This radiation is so strong that it alters the atomic structure of other materials during the penetration: it displaces negatively charged particles called electrons. The remaining atoms or molecules are electrically charged positively, they are called ions. The radiation emitted by radioactive substances is therefore also known as ionizing radiation.
Physics: Principles brief
Radioactive substances can occur naturally or are produced artificially. Well known examples are uranium, radium, plutonium, or as the radioactive noble gas radon. In nature, however, there are also radioactive "variants" of many other, usually more stable substances: As known nuclides and isotopes is known substances whose nucleus contains additional sub-atomic particles, namely, additional neutrons. They usually have the same chemical properties as the "normal" form, but are less stable. Many can therefore decay radioactively.
An example is carbon: The core of carbon atoms (chemical abbreviation "C") usually contains six protons and neutrons as many, he is surrounded by six electrons. A variant does contain the same number of protons and electrons, has but two and thus a total of eight additional neutrons, and is weakly radioactive. The chemical notation is "14C". "14" is called the mass number, which you get when you add up protons and neutrons of an atom. 14C-carbon occurs when also present in small amounts in all living organisms.
Radioactive isotopes exist in nature from other chemical elements. Many can now also be produced artificially.
Radiation: wave or particle?
Radioactive, or better, ionizing radiation can be explained physically as well as beam of energetic particles as well as an electromagnetic wave: can happen when decay of unstable radioactive substances of different things, depending on the situation of the properties of the material, but also depending on the particular.
Some substances emit subatomic particles from the nucleus, the energy from these protons and neutrons, are called Alpha radiation (α-radiation). However, where a free electron decay, it is called beta radiation (β) radiation or electron beams. Gamma radiation (γ radiation) is a particularly high-energy radiation. The term commonly used X-ray radiation is a radiation in the spectrum so to speak, between the gamma-radiation and a very intense, but non-ionizing ultraviolet radiation (UV).
Ionizing radiation is produced not only on earth: Even as cosmic radiation from space they can, albeit slowed considerably or completely through the atmosphere to strike the earth.
Energy: Units and Measurement
For measurement of radioactivity among physicists, such that there are many decays per unit time for a radioactive substance. The physical unit is becquerel: A Becquerel (Bq) means one disintegration per second.
The "half life" refers to the time when the decay is half of a radiating substance. Radioactive elements behave the same: For plutonium, the half-life of 24.11 years. In 131Jod, which is used in medicine, however, it takes little more than a week, break up the half.
In the unit Gray (Gy) of absorbed dose of ionizing radiation is given, for example, in medical radiation therapy.
Not to be confused so that detail in unit Sievert (Sv) are. Again, while the absorbed dose is meant to ionizing radiation. To calculate the combined effects of radiation on living organisms are in this unit but the dose with standard values for tissue sensitivity: These are defined for each organ or tissue of the International Commission on Radiological Protection (www.icrp.org). In Sievert experts give therefore the radiation exposure of the background radiation from the environment or radiation accidents.
No longer used, the earlier customary units Rem (replaced by Sievert) or wheel (replaced by Gray).
Ionizing Radiation: What does it do to the body?
All biological molecules and also the water contained in the body slow down from radiation. This energy is released. She is responsible for the effects of ionizing radiation and triggers in living tissue as previously described change in the charge of atoms and molecules.
The resulting ions are very reactive. You immediately try to enter into chemically stable compounds again - not always those that are useful for the body or "right".
Thus, ionizing radiation, for example, important enzymes do not function or destroy cell components and cell death. But it can also lead to large molecules, the DNA changes that are passed on to the next cell division to daughter cells and contribute to long-term development of cancer.
Healthy cells are able to repair a lot of damage or damaged structures specifically to degrade. The radiation dose is very high, or the affected tissues are particularly sensitive, does not this natural protection. In general, however: Even a very low radiation dose may be sufficient under adverse circumstances, to destroy tissue or to stimulate tumor development.
* A lower limit or threshold below which ionizing radiation would be harmful, there is not.
Which organs or organ systems are particularly at risk also depends on the route by which they were affected by radiation and how long these acts: radioactive nuclides, which release in the decay radiation, the body breaks often, instead of the radioactive isotopes with similar chemical properties in tissues, organs or bone. Their action then stops until the body is excreted or they are completely disintegrated. Radioactive iodine, for example, uses the body as "normal" mainly iodine in the thyroid.
The range of the radiation is released in many of these substances is so low that other tissues are hardly affected.
For external irradiation, either for therapeutic purposes in medicine, on the plane on long haul flights or radiation accidents, the adverse effect is however only as long as the acts outside the human body radiation source. The radiation also acts only where it actually hits the tissue and penetrates and is decelerated not already in the skin. Cancer patients who are irradiated for treatment are not even "radioactive".
Sources: What are radioactive substances, where there is ionizing radiation?
The Federal Office for Radiation Protection (BfS) is the average load from the environment currently with about a total of 2.1 mSv per year (www.bfs.de / en / ion faq_istrahlung.html / faq /. Depending on where you live, eating and living habits The radiation exposure, but may range between one and ten mSv. sources of such radiation are naturally occurring radon, other radioactive substances from rocks and soil or derived building materials. This natural radiation are absorbed by plants and animals from the environment and reach the people of his food and even about "stimulants" such as tobacco.
Also contributes to background levels even cosmic radiation from outer space, for example by the sun. It is slowed down by the air surrounding the earth at sea level is therefore lower than the dose in the mountains or when flying.
Natural and human sources
To calculate the average total load in Germany, attracts the Federal Office for Radiation Protection approached other sources, namely the so-called civilization radiation origin. These include the medical use of radiation, such as x-ray or in the treatment of cancer. Further contribute to this day former nuclear weapons testing or the nuclear accident at Chernobyl.
exists for the monitoring of current nuclear power plants or other sources of civilization in Germany, a nation-wide and area-wide monitoring network (www.bfs.de / en / ion / imis).
Common questions about the cancer risk from radiation:
Of what can you protect yourself What are not you?
How big is the risk of cancer, if you were often X-rayed?
A general answer to this question is hardly possible to vary the load from different X-rays, from capture to the dentist on mammography or the diagnosis for a suspected fracture to the CT scan.
The annual burden can therefore be quite different depending on whether someone needed for a serious disease, multiple CT scans or X-rayed at the dentist was only once. The Federal Office for Radiation Protection, however, controls what values used annually in Germany as a whole (www.bfs.de/de/bfs/druck/uus/jb06_Teil_B_IV.pdf).
In medicine is also always the question of the importance of the risk would be higher - but most of the low radiation exposure, or an undiagnosed illness. Investigation process can also not replace any against each other, so it is not, as feared, often, an "economy measure" when a doctor attaches instead of an ultrasound scan or, possibly, more expensive magnetic resonance imaging an X-ray examinations, such as mammography, and buys a radiation burden for this.
Investigations such as scintigraphy, in which the gift radiant particles of certain changes in the body even makes it visible, can usually also do not replace other methods.
Nevertheless, in respect of each radiograph were definite indications exist, unnecessary or duplicate studies should be avoided at all costs: Patients who change as the doctor or the family doctor referred to various specialists, if possible always ask for records such as X-rays given or directly the new doctors can be provided.
Details on exposure to individual procedures, the Federal Office for Radiation Protection under www.bfs.de / en / health ion.
Can mushrooms and game meat from Eastern Europe
or eat there are still radioactive
Impacts of the Chernobyl disaster?
The reactor accident in Chernobyl for many years still have an impact on the contamination of soils and therefore foods with radioactive substances.
The Federal Office for Radiation Protection rejected last 2006 point out that not only in Eastern Europe but also in some regions of Germany, some fungal species and wildlife are still highly contaminated. These mainly include southern Bavaria and the Bavarian Forest (www.bfs.de / en / ion / foods / pilze_wildbret.html). A measurable risk but probably only for people who eat a lot of wild meat and mushrooms from these regions.
Foods that are produced in these regions by agriculture, are among the usually less contaminated than wild plants: by plowing and other tillage do not remain radioactive substances so concentrated on the surface preserved as it is in forest and meadow areas of the case. More on the contamination of food, BfS has also www.bfs.de / en / ion / foods.
What is the risk to go a frequent flyer by the cosmic radiation?
This question was addressed in recent years in several large studies. While for the scientists, the risk was important to take the pilots and cabin crew, flying so over decades also almost daily. From such studies it is now believed that opportunity flyer as most tourists increase their radiation risk and no pregnant women or young children also received no measurable risk. For the protection of employees in aviation, but in 2003 the Radiation Protection Ordinance was changed: the burden of affected professions will now be reviewed periodically by the Federal Aviation Authority and must not exceed certain limits. Tables for radiation exposure, which guides and other frequent travelers can is, the Federal Office for Radiation Protection available here (www.bfs.de / en / ion / anthropogenic / flugpassagiere.html).
How dangerous is radon?
Why is sometimes before bed
or work warned in a basement?
Radon is everywhere in the world occurring gas, colorless, odorless and tasteless, with a short half-life of about 3.8 days. It is, according to the Federal Office for Radiation Protection (BfS), Germany responsible for the greatest burden from natural radiation sources: The collapse even more severe and more radioactive elements radon formed in the earth constantly. It collects, depending on the surface and permeability of rocks, particularly in caves, mines and tunnels may, under certain circumstances, but also penetrate into buildings. The gas accumulates particularly in basements and lower floors, but can already be effectively removed by ventilation.
Radon decays occur more or less short-lived other substances that attach to fine particles of dust in the air and are then inhaled. In particular, the respiratory tract and lungs and affect the radiation.
Back in the 16th Century it was known that in some mining areas of Germany under miners lung disease most frequently occurred. Today we know that it dealt to lung cancer and radon was the catalyst. The Federal Office for Radiation Protection estimates that radon is responsible for several percent of lung cancer in Germany, smokers are particularly at risk from radon. From current studies, we know that the risk may increase other cancer from radon exposure (www.bfs.de/de/bfs/presse/pr08/pr0824.html).
Is it true that cigarettes contain radioactive substances?
All plants can absorb radioactive substances from the soil on which they grow. Are fruits, vegetables and other plants consumed as food, they also get into the body of man. Through the food chain itself may contain animal foods radiating elements.
found in tobacco, among other 210Polonium, an alpha emitter, which passes through the smoke in the respiratory tract and lungs.
More about the WHO Collaborating Centre for Tobacco Control at the German Cancer Research Centre together than to PDF text upload www.dkfz.de / de / tobacco control, keyword "tobacco products and additives," keyword "poisons in tobacco smoke," keyword "tobacco smoke - a toxic mixture.
To know more: Links and addresses
- In its "investigation" of the Cancer Information Service provides information on diagnostic procedures, for which the radiation or radioactive substances are used. These include computed tomography, mammography, PET or scintigraphy.
- In the "treatment" says the text "radiation therapy and nuclear medicine applications in cancer therapy.
- Also non-ionizing radiation is discussed as a risk of cancer: Ultraviolet light is occupied as a possible cause of skin cancer. not yet concluded the discussion of the so-called "electronic smog" is.
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