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Radiation effects

Ionising radiation transports energy. When this radiation energy hits biological tissue - for example in the human body - it is taken up (absorbed) by the tissue. The absorbed energy may produce manifold effects. If and to what extent the radiation exposure of an organism leads to health damage depends on the absorbed radiation dose, the type of radiation and which organ or body tissue is mainly affected. If the radiation dose is very high, tissue or even the entire organism may die. Radiation damage can, however, also be repaired. But, if repair is faulty, the long-term result may be the development of cancer or leukaemia, for instance.

What are the effects of ionising 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.

Cancer

Ionising radiation can cause cancer. Cancers are malignant neoplasms. Malignant tumours affect an organ and leukaemia is a disease of the blood-forming system that has an effect on the whole organism. Much the same applies to lymphomas, malignant neoplasms of the lymphatic system which also affect the whole organism.

Drawing of a house with three persons and radon in the ambient air

How radon affects health

Inhaling radon and its radioactive decay products over a longer time increases the risk of lung cancer. Approximately 5% of all lung cancer deaths in Germany can be attributed to radon. Radon is therefore one of the most important causes of lung cancer after smoking.

Possible positive effects of ionising radiation - hormesis

It is highly controversial, whether low doses of ionising radiation may possibly have a positive effect on biological systems. The positive effects seen sporadically but often just claimed are gathered under the term "hormesis". The manifestations of these positive effects are manifold and variable. These effects cannot be observed regularly in studies conducted under almost identical conditions.

Consequences of a radiation accident

The International Atomic Energy Agency's (IAEA) criteria for health consequences of radiation accidents are summarized in "Planning the medical response to radiological accidents", Vienna, IAEA, 1998.

Hereditary radiation damage

When ionising radiation acts upon gonads or germ cells, it may cause damage to the genetic material (mutations) which can lead to genetically induced diseases (hereditary defects). These may result in malformations, metabolic disorders, immune deficiencies etc. in the children or grandchildren of exposed individuals or may only become apparent after many generations.

Epidemiology

Epidemiology (derived from Greek epi "on, upon", demos "people", logos "study") is a scientific discipline studying the distribution of diseases in a population (descriptive epidemiology) and the factors influencing this distribution (analytical epidemiology).

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