Radiation is the energy that comes out of the source and travels through space and may even be able to penetrate through various materials. Sunshine is one of the familiar forms of radiation that delivers heat, sunshine and light. While we enjoy and depend on it, we also control our exposure to it. This is because prolonged exposure to certain radiations can lead to health problems and can eventually lead to death. In this article, let us discuss the types of radiation.
Types Of Radiation
Following are the types of radiation based on the energy of the radiated particles:
- Ionizing radiation
- Non-ionizing radiation
Ionizing radiation has sufficient energy to produce ions in the matter at the molecular level. If that matter is human significant damage can result including damage to DNA and denaturation of proteins. This is not to say that non-ionizing radiation can’t cause injury to humans but the injury is generally limited to thermal damage i.e. burns. There is a great deal of information on the above chart. One of the most interesting things is that the visible spectrum is essentially the divide between ionizing and non-ionizing radiation. This makes sense clinically when we think of UV radiation causing skin cancer.
Types of Ionizing Radiation
Ionising radiation is caused due to unstable atoms that either has excess energy or mass or both. In order for them to get back to a stable state, they have to release the extra mass or energy in the form of radiation. Given below are the different types of ionizing radiation along with a few of their characteristics:
- Alpha particles
- Beta particles
- Gamma rays
What are alpha particles?
The particles consisting of two protons and two neutrons that are bound together are known as alpha particles. These particles are identical to the helium atom and are emitted during radioactive decay and are known as alpha decay.
Properties of alpha particles
|Nature||Positive charge particles|
Uses of alpha particles
Following are the uses of alpha particles:
- They are used as smoke detectors. When the smoke enters the detectors, the number of alpha particles reduce and get detected by the alarm. Americium-241 is an example of a smoke detector.
- They are used as static eliminators to remove the static charges from the equipment. Polonium-210 is an example of static eliminator.
What are beta particles?
Particles that are having high energy electrons or positrons are known as beta particles. These are ejected during the radioactive decay and are known as beta decay.
Properties of beta particles
|Nature||Negatively charged particles|
Uses of beta particles
Following are the uses of beta particles:
- Strontium-90 is used for the treatment of bone cancer.
- For emergency lighting, tritium is used.
What are gamma rays?
During radioactive decay, a packet of electromagnetic energy is emitted by the nucleus known as a gamma ray. In the electromagnetic spectrum, gamma photons are the most energetic photons.
Properties of gamma rays
|Nature||Uncharged electromagnetic radiation|
|Natural source||Excited nuclei formed due to alpha and beta decay|
Uses of gamma rays
Following are the uses of gamma rays:
- Cobalt-60 is used for sterilization of medical equipment and pasteurisation of food.
- Caesium-137 is used for the measurement of soil moisture density and to measure and control the flow of liquids in industries.
What are X-rays?
X-ray is a packet of a photon that is produced by electrons that are external to the nucleus. They originate from the electron cloud of an atom.
Properties of X-rays
|Physical||They are invisible to eyes but have the property of attenuation, absorption and scattering|
|Chemical||They produce highly active radical of OH ions that can bring chemical changes in the solution|
|Biological||They are used for cancer treatment and may cause genetic changes|
|Physiochemical||They are used for producing photographic films|
Uses of X-rays
- X-rays are used for crystallography and fluoroscopy to control the quality of materials.
- X-rays are used to detect tumours and infections.
Non – Ionizing Radiation
Since every state workplace has one or more natural or man-made sources of non-ionizing radiation, these requirements apply to every state employee. Electromagnetic radiation is produced by moving electric charges and may be of natural origin (e.g. the sun) or may be of human origin (e.g. electronic devices). There are two types of electromagnetic radiation ionizing and non-ionizing and there are two types of non-ionizing radiation optical and radio-frequency. Following are the types of non-ionizing radiation:
- Ultraviolet radiation
- Visible light
- Radio waves
- Very Low Frequency (VLF)
- Extremely Low Frequency (ELF)
- Thermal radiation
- Black-body radiation
What is ultraviolet radiation?
Sunlight is the main source of ultraviolet (UV) radiation. Prolonged exposure of skin to this radiation leads to skin cancers. Sun lamps and tanning beds also emit UV rays. It has a wavelength of 400 nm.
Types of UV radiation
Following are the types of UV radiation:
What is visible light?
Visible light is defined as the electromagnetic spectrum that is visible to the human eye. When the full spectrum passes through the prism, the spectrum separates depending on their wavelength into the colours of the rainbow. The shortest wavelength (380 nm) is of violet and the longest wavelength (700 nm) is of red.
Infrared radiation (IR) is also known as infrared with the wavelength range 700 nm to 1 mm. These are longer than the visible light. Near wavelength, mid-wavelength, long wavelength and far infrared are the different categories of infrared.
Uses of infrared waves
Following are the uses of infrared waves:
- Thermography is a method to determine the relative temperature of the object and for this infrared waves are used.
- Infrared waves are invisible but can be sensed as they conduct heat. Because of this property, infrared waves are used in physical therapy for heating purposes.
What are microwaves?
Microwaves are waves with different wavelengths and frequencies. They have a wavelength of 30 cm to 1 mm and frequency between 300 MHz and 300 GHz.
What are radio waves?
Radio waves are the electromagnetic radiation that has a wavelength longer than infrared and travel at a speed of light. The propagation characteristics of the radio waves have different frequencies like long waves to cover the earth and short waves that get reflected off in the ionosphere.
Uses of radio waves
Following are the uses of radio waves:
- Radio waves are used for mobile radio communication.
- Radar and satellite communication.
- For navigation systems.
Following are the links for other types of non-ionizing radiation:
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