Radiation refers to the emission or propagation of energy in the form of electromagnetic waves or subatomic particles through space or a material medium.
This radiant energy can be in the form of electromagnetic radiation, such as visible light, X-rays and gamma rays, or in the form of subatomic particles, such as electrons, protons or neutrons. Radiation can have a variety of effects, from being beneficial in medical or technological applications to being potentially harmful to health if exposed to high levels or for prolonged periods.
Below are some examples of radiation.
Electromagnetic radiation is a form of energy that spreads through space in the form of electromagnetic waves. These waves are composed of oscillating electric fields and magnetic fields, which propagate at the speed of light.
This type of radiation covers the entire electromagnetic spectrum, which is divided into different regions depending on the frequency and wavelength of the waves. Visible light, x-rays, gamma rays, and radio waves are examples of forms of electromagnetic radiation.
Additionally, microwaves are a form of electromagnetic radiation that is commonly used in applications such as microwave ovens, wireless communications, and radar. Although they are relatively safe for humans at normal exposure levels, exposure to high levels of microwaves can be harmful.
Electromagnetic radiation is present in numerous situations in our daily lives. Below we list some examples in everyday activities:
- Radio Communications : The radio signals we use to transmit information, such as AM and FM radio broadcasts, mobile radio signals (2G, 3G, 4G, 5G), Wi-Fi signals, and television, are examples of this type of radiation.
- Home Appliances : Many home appliances and electronic devices emit electromagnetic radiation in the form of frequency waves, such as microwave ovens, mobile phones, televisions, radios, Wi-Fi routers, and induction ovens.
- Artificial lighting : The bulbs and lamps that we use in our daily lighting, such as incandescent bulbs, fluorescent bulbs and LED lights, emit electromagnetic radiation in the form of visible light.
- X-rays and radiographs : When we need to obtain diagnostic medical images, such as dental, bone or internal organ x-rays, x-ray machines are used that are capable of passing through soft tissues but being absorbed by denser structures, allowing useful medical images to be obtained.
- Security scanners : At airports and other security locations, full-body or baggage scanners are used that emit low-intensity electromagnetic radiation, such as millimeter waves or terahertz waves, to detect hidden objects without requiring physical contact.
The Sun emits a wide range of electromagnetic radiation, including visible light, infrared rays and ultraviolet rays. These types of radiation are important for life on Earth, but excessive exposure to ultraviolet radiation can be harmful.
Examples of day-to-day life in which solar radiation intervenes:
- Natural lighting : Solar radiation provides natural light during the day, allowing us to see and carry out our daily activities without depending so much on artificial lighting.
- Solar heating : Solar radiation is a natural heat source. In cold climates, solar energy can be used to heat water in solar water heating systems. Additionally, direct exposure to solar radiation can heat our environment.
- Electricity generation : Solar radiation can be converted into electricity using photovoltaic solar panels. More and more homes and buildings are using solar energy as a renewable energy source to power electronic devices.
- Agriculture : Solar radiation is essential for plant growth through photosynthesis. Plants use solar energy to convert carbon dioxide and water into sugars and oxygen. Farmers depend on solar radiation for crop growth, and the amount of sunlight plants receive can influence their development and performance.
In everyday life, exposure to nuclear radiation is generally very low and controlled. However, there are some examples where nuclear radiation may be present:
- Nuclear medicine imaging : In nuclear medicine, radiopharmaceuticals are used, which are chemical compounds combined with small amounts of radioactive radioisotopes.
- Radiation therapy : Radiation therapy uses ionizing radiation to treat and control the growth of cancer cells. Radiation therapy machines emit high-energy radiation, such as gamma rays, that specifically targets areas affected by cancer.
- Nuclear power plants : Nuclear power plants generate electricity through the nuclear fission of uranium or plutonium.
- Radioactive contamination : Although it is not a common everyday example, in cases of nuclear accidents such as the Fukishima accident or spills of radioactive material as happened with the Hisashi Ouchi case in Japan, exposure to nuclear radiation can occur in an uncontrolled manner.
Cosmic radiation is a form of radiation that comes from outer space, mainly from the Sun and extraterrestrial sources. Astronauts in space are exposed to higher levels of cosmic radiation due to the lack of atmospheric protection.
Here are some examples of cosmic radiation:
- Cosmic background radiation : Cosmic background radiation is a form of electromagnetic radiation that fills the entire universe and originated shortly after the Big Bang. This is microwave radiation that is in the frequency range of radio waves.
- Cosmic rays : Cosmic rays are high-energy particles, primarily protons and atomic nuclei, that originate from violent astrophysical events, such as supernova explosions.
- Solar Radiation : Solar radiation, although mentioned above, is also considered a form of cosmic radiation. The Sun emits a wide range of electromagnetic radiation, including visible light, ultraviolet radiation, X-rays and gamma rays.
- Galactic radiation : Galaxies emit radiation in different forms, including radio waves, visible light, x-rays, and gamma rays. This radiation can come from sources such as stars, nebulae, black holes, and other celestial objects.
Radio frequency radiation
Radio frequency radiation includes radio waves used in wireless communications, such as FM radio, television, and mobile phones. Although exposure to low levels of radiofrequency radiation is considered safe, some studies suggest possible long-term health effects.
Radio frequency (RF) radiation is a type of electromagnetic radiation, so the main difference between the two terms lies in its scope and use. This type of radiation covers lower frequencies, generally between 3 kHz (kilohertz) and 300 GHz (gigahertz).