Why are ionising radiations dangerous

The beta particle is either a positron or an electron. Neutrons emitted during some nuclear decay processes are often included as ionizing particles but they do not actually ionize an atom directly. Neutrons interact with another nucleus, which may result in a secondary process involving ionizing radiation. Why is ionizing radiation dangerous?

Not all cells are affected by ionizing radiation in the same way. The cells that reproduce the most and are the least specialized are the most likely to be affected by ionizing radiation, for example those in a forming fetus.

Radiation is effective as a cancer treatment because it can kill the cancer cells, however it can also kill or damage nearby cells. When radiation is used to treat cancer it must be pinpointed very carefully.

New technologies, similar to imaging techniques used in CT scans, called TomoTherapy help pinpoint radiation treatment. Some aggressive cancers, such as liver cancer, are being treated with a new internal method or radiation therapy.

Sent through an artery that feeds the liver, microscopic encapsulated spheres containing radioactive isotopes get directly embedded into the liver and destroy cancer cells.

Internal radiation treatment is called brachytherapy. There is background radiation all around us. Most cement, stoneware, and granite contain some radioactive particles, but the levels are not so high. The fuel rods in a nuclear reactor are made of zirconium and pellets of naturally occurring uranium that has been processed by humans so that it contains a higher percentage of the uranium isotope.

This isotope occurs naturally and its nuclear decay process emits more energy. These fuel rods are placed in water and the water heats up due to the ionizing energy emitted by the nuclear decay processes that occur in the fuel rods. The steam pushes on a turbine, causing it to turn and as it turns electricity is generated. When living organisms are exposed to the low amounts of background radiation there is very little affect overall on the organism. This conclusion assumes that there is likely no safe dose level i.

Radiation protection standards are based on the premise that any radiation dose carries some risk, and that risk increases with dose. Deterministic health effects can occur when a part of the body receives a radiation dose that exceeds the threshold for that health effect.

Some of these health effects e. In most controlled occupational settings, workers are not likely to receive radiation doses that would result in such effects. At lower doses, particularly below 50 rad 0. Other deterministic effects at lower radiation doses include:. Radiation injury to the skin may cause symptoms such as itching, tingling, redness, and swelling.

Cutaneous radiation injury CRI occurs when a high radiation dose of rad 2 Gy or higher causes injury to the skin. Depending on the radiation dose, symptoms of acute radiation syndrome see section below may also occur. Acute radiation syndrome ARS occurs when all or most of the body receives a very high dose—around 70 rad 0. CDC provides additional information about the stages of ARS and the radiation doses associated with the different ARS syndromes bone marrow, gastrointestinal, cardiovascular, central nervous system , including ARS fact sheets for the general public and clinicians.

Because ionizing radiation is strictly regulated, it is unlikely that workers would receive very high doses of penetrating radiation able to reach internal organs to the whole body. Doses sufficient to produce ARS and potentially cause death are associated with catastrophic radiation emergencies, and not the types of radiation doses that workers receive on a day-to-day basis.

For example, the Chernobyl Nuclear Power Plant accident in Ukraine resulted in acute doses following a release of massive amounts of radioactive material. Approximately plant workers and firefighters battling the fire during this radiation emergency at the Chernobyl plant received high radiation doses and suffered from ARS. Publication No. Safety and Health Topics Ionizing Radiation. Ionizing Radiation. Health Effects This section provides information about health effects associated with ionizing radiation.

In general, radiation dose is received when a worker is: In close proximity to an unshielded or partially shielded radiation source. Unprotected when near unshielded radiation-generating machines e. Unprotected when handling radioactive materials e. In close proximity to surfaces or areas contaminated with radioactive materials e. Contaminated with radioactive materials.

Types of Health Effects When ionizing radiation interacts with cells, it can cause damage to the cells and genetic material i. It is hard to set one standard threshold above which radiation exposure becomes seriously harmful since the definition of "seriously harmful" is subjective.

Medium-low doses of ionizing radiation can still cause nausea and may still cause a miniscule increase in the chance of getting cancer, although this increase may be too small to be considered significant.

Despite the complexity of this field, general safety thresholds can still be set. Experimentally, cancer risk has only been found to increase for doses above mSv per year according to the World Nuclear Association. A good safety threshold should therefore be set at a value that is well below mSv per year.

The U. Nuclear Regulatory Commission sets the occupational safety limit for ionizing radiation exposure to be 50 mSv per year. For comparison, natural background radiation provides a dose of 3 mSv per year, a single typical banana provides 0.

As you can see, a single medical scan is too weak to cause harm even though it may involve ionizing radiation. On the other hand, undergoing several full-body CT scans in a short period of time can make the radiation add up to a total dose that is at a harmful level.

For this reason, medical doctors are trained to avoid ordering too many radiation-intensive scans for a single patient in a short amount of time unless the benefits outweigh the risks, e. When the dose is high enough, ionizing radiation causes two types of harm to humans: direct tissue damage and cancer.