Radiation is the transport of energy through waves or particles. Sunlight, radio waves, X-rays used in medical imaging, and particles emitted by some radioactive substances are examples of different types of radiation.
“Radiation” alone does not indicate a level of risk. The type of radiation, energy, dose received, duration of exposure and exposed tissues should be evaluated together.
Difference between ionizing and non-ionizing radiation
Radiation is generally considered in two main groups according to its effect on matter.
non-ionizing radiation
Radio waves, microwaves, visible light and infrared radiation are considered in this group. The energy of these types of radiation is not sufficient to create ions by removing electrons from atoms.
ionizing radiation
X-rays, gamma rays, and some high-energy particles are examples of ionizing radiation. Because they have sufficient energy, they can cause ionization in the matter they pass through. They are among the types of radiation used in a controlled manner in medicine, industry, research and energy production.
Alpha, beta, gamma and neutron radiation
- Alpha particles: It is relatively heavy and electrically charged. Their ability to penetrate is low; However, taking an alpha emitting substance into the body requires a different evaluation.
- Beta particles: It may consist of high-speed electrons or positrons. It can penetrate further than alpha particles.
- Gamma rays: It is electromagnetic radiation and can penetrate further into materials without proper shielding.
- Neutrons: They are particles that do not carry an electrical charge. It is especially important in reactor and some research environments; The protection approach is chosen according to the energy level.
These short definitions answer the question “which is more dangerous?” It does not answer the question on its own. Risk; It is evaluated together with the location of the source, its activity, energy level, route of exposure and dose received.
Is radiation found only in nuclear facilities?
No. People are exposed to radiation from natural and artificial sources. Cosmic rays, natural radioactive substances in the earth's crust and radon come from natural sources; Medical imaging and some industrial applications are examples of artificial sources.
Being natural does not mean that a resource is harmless under all conditions, and being artificial does not automatically mean that it is dangerous. Scientific evaluation is based on measured dose and exposure conditions.
How is radiation measured?
Different units are used for different quantities related to radiation:
- Becquerel (Bq): It refers to the rate of decay in a radioactive source.
- Gray (Gy): It defines the amount of energy a substance absorbs.
- Sievert (Lv): It is used in radiation protection quantities that take into account the type of radiation and weighting factors related to biological effects.
These units are not interchangeable. The activity of a source in becquerels alone does not tell us the dose in sieverts a person receives.
Three basic approaches to radiation protection
Practically, three basic approaches stand out in radiation protection:
- Duration: Reducing the time spent near the source.
- Distance: Increasing the distance from the source.
- Armoring: Using protective equipment appropriate to the type of radiation.
In professional applications, these include source control, dosimetry, field monitoring, training and operating procedures.
Frequently asked questions
Can radiation be seen or smelled?
Ionizing radiation cannot be directly detected by human senses. For this reason, measuring devices and monitoring programs are used.
Is all radiation exposure the same?
No. Type, energy, dose rate, duration, and tissue exposed are important. A medical practice and an uncontrolled welding incident are not considered in the same context.
Is cell phone radiation the same as X-ray?
Both can be explained broadly within the scope of electromagnetic radiation; However, their energy levels and the way they interact with matter are different. X-rays are in the ionizing radiation class, while the radio frequency fields used by mobile phones are in the non-ionizing radiation class.
Resources
- TENMAK, What is Radiation?: https://www.tenmak.gov.tr/nuken/ogrenci/bolum4_03.html
- IAEA, Radiation, People and the Environment: https://www.iaea.org/sites/default/files/radiation0204.pdf
- TENMAK, Nuclear Energy Research Institute: https://www.tenmak.gov.tr/nukleer-enerji-arastirma-enstitusu