Infrared radiation is a natural form of radiation. Every person is exposed to it daily. A huge part of the energy of the Sun comes to our planet in the form of infrared rays. However, in the modern world there are many devices that use infrared radiation. It can affect the human body in various ways. It largely depends on the type and purpose of using these very devices.
What is this
Infrared radiation, or IR rays, is a type of electromagnetic radiation that occupies the spectral region from red visible light (which is characterized by a wavelength of 0.74 microns) to short-wave radio radiation (with a wavelength of 1-2 mm). This is a fairly large area of the spectrum, so it is further subdivided into three areas:
- near (0,74 - 2.5 µm);
- medium (2.5 - 50 microns);
- far (50-2000 microns).
Discovery history
In 1800, a scientist from England, W. Herschel, made the observation that in the invisible part of the solar spectrum (outside the red light), the temperature of the thermometer rises. Subsequently, the subordination of infrared radiation to the laws of optics was proved and a conclusion was made about its relationship with visible light.
Thanks to the work of the Soviet physicist A. A. Glagoleva-Arkadyeva, who received radio waves with λ=80 μm (IR range) in 1923, the existence of a continuous transition from visible radiation to IR radiation and radio waves was experimentally proved. Thus, the conclusion was made about their common electromagnetic nature.
Almost everything in nature is capable of emitting wavelengths corresponding to the infrared spectrum, which means it is a source of infrared radiation. The human body is no exception. We all know that everything around is made up of atoms and ions, even humans. And these excited particles are capable of emitting IR line spectra. They can go into an excited state under the influence of various factors, for example, electrical discharges or when heated. Thus, in the radiation spectrum of a gas stove flame there is a band with λ=2.7 µm from water molecules and with λ=4.2 µm from carbon dioxide.
IR waves in everyday life, science and industry
Using certain devices at home and at work, we rarely ask ourselves about the effect of infrared radiation on the human body. Meanwhile, infrared heaters are quite popular today. Their fundamental difference from oil radiators and convectors is the ability to heat not the air itself directly, but all objects in the room. That is, furniture, floors and walls are heated first, and then they give off their heat to the atmosphere. At the same time, infrared radiation also affects organisms - humans and their pets.
IR rays are also widely used in data transmission and remote control. Many mobile phones have infrared ports for exchanging files between them. And all the remote controls for air conditioners, music centers, TVs, some controlled children's toys also use electromagnetic rays in the infrared range.
The use of infrared rays in the army and astronautics
The most important infrared rays are for the aerospace and military industries. On the basis of photocathodes that are sensitive to infrared radiation (up to 1.3 microns), night vision devices (various binoculars, sights, etc.) are created. They allow, while simultaneously irradiating objects with infrared radiation, to aim or observe in absolute darkness.
Thanks to the created highly sensitive receivers of infrared rays, the production of homing missiles became possible. Sensors in their head react to the IR radiation of the target, which is usually warmer than the environment, and guide the missile to the target. Based on the same principledetection of heated parts of ships, aircraft, tanks using heat direction finders.
IR locators and rangefinders can detect various objects in complete darkness and measure the distance to them. Special devices - optical quantum generators that emit in the infrared region, are used for space and long-range terrestrial communications.
Infrared radiation in science
One of the most common is the study of emission and absorption spectra in the IR region. It is used in the study of the features of the electron shells of atoms, to determine the structures of various molecules, and in addition, in the qualitative and quantitative analysis of mixtures of various substances.
Due to differences in the coefficients of scattering, transmission and reflection of bodies in the visible and IR rays, photographs taken under different conditions are somewhat different. Infrared images often show more detail. Such images are widely used in astronomy.
Studying the effect of infrared rays on the body
The first scientific data on the effect of infrared radiation on the human body date back to the 1960s. The author of the research is the Japanese doctor Tadashi Ishikawa. In the course of his experiments, he was able to establish that infrared rays tend to penetrate deep into the human body. At the same time, thermoregulation processes occur, similar to the reaction to being in a sauna. However, sweating starts at a lower ambient temperature (itis about 50 ° C), and the heating of the internal organs occurs much deeper.
During this heating, blood circulation is increased, the vessels of the respiratory system, subcutaneous tissue and skin expand. However, prolonged exposure to infrared radiation on a person can cause heat stroke, and strong infrared radiation leads to burns of varying degrees.
IR protection
There is a small list of activities aimed at reducing the risk of exposure to infrared radiation on the human body:
- Reducing the intensity of radiation. It is achieved through the selection of appropriate technological equipment, the timely replacement of obsolete equipment, as well as its rational layout.
- Removal of workers from the source of radiation. If the production line allows, remote control of the production line should be preferred.
- Installation of protective screens on the source or workplace. Such fences can be arranged in two ways to reduce the effect of infrared radiation on the human body. In the first case, they must reflect electromagnetic waves, and in the second case, they must delay them and convert the radiation energy into thermal energy, followed by its removal. Due to the fact that protective screens should not deprive specialists of the opportunity to monitor the processes taking place in the production, they can be made transparent or translucent. For this, silicate orquartz glass, as well as metal meshes and chains.
- Thermal insulation or cooling of hot surfaces. The main purpose of thermal insulation is to reduce the risk of burns to workers.
- Personal protective equipment (various overalls, goggles with built-in light filters, shields).
- Preventive measures. If in the course of the above actions the level of exposure to infrared radiation on the body remains high enough, then an appropriate mode of work and rest should be selected.
Benefits for the human body
Infrared radiation affecting the human body leads to improved blood circulation due to vasodilation, better saturation of organs and tissues with oxygen. In addition, an increase in body temperature has an analgesic effect due to the effect of rays on the nerve endings in the skin.
It has been noticed that surgical operations performed under the influence of infrared radiation have a number of advantages:
- pain after surgery is somewhat easier to bear;
- faster cell regeneration;
- The effect of infrared radiation on a person avoids the cooling of internal organs in case of surgery on open cavities, which reduces the risk of shock.
In patients with burns, infrared radiation creates the possibility of removing necrosis, as well as performing autoplasty at an earlier stage. In addition, the duration of fever is reduced, anemia and hypoproteinemia are less pronounced, and the frequency of complications is reduced.
It has been proven that infrared radiation can weaken the effect of some pesticides by increasing nonspecific immunity. Many of us know about the treatment of rhinitis and some other manifestations of the common cold with blue IR lamps.
Harm to humans
It is worth noting that the harm from infrared radiation for the human body can also be very significant. The most obvious and common cases are skin burns and dermatitis. They can occur either with too long exposure to weak waves of the infrared spectrum, or during intense irradiation. When it comes to medical procedures, it is rare, but still, heat strokes, asthenia and exacerbation of pain occur with improper treatment.
One of the modern problems is eye burns. The most dangerous for them are IR rays with wavelengths in the range of 0.76-1.5 microns. Under their influence, the lens and aqueous humor are heated, which can lead to various disorders. One of the most common side effects is photophobia. This should be remembered by children playing with laser pointers, and welders who neglect personal protective equipment.
IR rays in medicine
Treatment with infrared radiation is local and general. In the first case, a local action is carried out on a certain part of the body, and in the second, the entire body is exposed to the action of the rays. The course of treatment depends on the disease and can range from 5 to 20 sessions of 15-30 minutes. When carrying out procedures, a prerequisite isuse of protective equipment. To maintain eye he alth, special cardboard pads or glasses are used.
After the first procedure, redness with indistinct borders appears on the surface of the skin, passing after about an hour.
The action of IR emitters
With the availability of many medical devices, people purchase them for personal use. However, it must be remembered that such devices must meet special requirements and be used in compliance with safety regulations. But most importantly, it is important to understand that, like any medical device, infrared wave emitters cannot be used for a number of diseases.
| Wavelength, µm | Useful action |
| 9.5 µm | Immunocorrective action in immunodeficiency states caused by starvation, carbon tetrachloride poisoning, use of immunosuppressants. It leads to the restoration of normal indicators of the cellular link of immunity. |
| 16.25 microns | Antioxidant action. It is carried out due to the formation of free radicals from superoxides and hydroperoxides, and their recombination. |
| 8, 2 and 6.4 µm | Antibacterial action and normalization of the intestinal microflora due to the influence on the synthesis of prostaglandin hormones, leading to an immunomodulating effect. |
| 22.5 µm | Results in the translation of manyinsoluble compounds, such as blood clots and atherosclerotic plaques, into a soluble state, allowing them to be removed from the body. |
Therefore, a qualified specialist, an experienced doctor should select a course of therapy. Depending on the length of the emitted infrared waves, the devices can be used for different purposes.
