Infrared radiation: effect on the human body, the effect of rays, their properties, benefits and harms, possible consequences

Infrared radiation is a natural type of radiation. Every person is exposed to it daily. A huge part of the energy of the sun enters our planet in the form of infrared rays. However, in the modern world there are many devices in which infrared radiation is involved. It can affect the human body in various ways. This largely depends on the type and purpose of using these same devices.

What it is

Infrared radiation, or infrared rays, is a type of electromagnetic radiation occupying the spectral region from red visible light (which is characterized by a wavelength of 0.74 μm) to short-wave radiation (with a wavelength of 1-2 mm). This is a fairly large region of the spectrum, therefore, it is further subdivided into three regions:

• near (0.74 - 2.5 microns);
• medium (2.5 - 50 microns);
• far (50-2000 microns).

Discovery story

In 1800, a scientist from England V. Herschel made an 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 infrared radiation and radio wave was experimentally proved. Thus, a conclusion was drawn about their general 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 man. And these excited particles are capable of emitting linear IR spectra. They can go into an excited state under the influence of various factors, for example, electric discharges or when heated. So, in the radiation spectrum of the flame of a gas stove 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 wonder about the effect of infrared radiation on the human body. Meanwhile, IR heaters are quite popular today. Their principal difference from oil radiators and convectors is the ability to heat not the air itself directly, but all the objects in the room. That is, first the furniture, floors and walls are heated, and then they give their heat to the atmosphere. At the same time, infrared radiation has an effect on organisms - man and his 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 remotes from air conditioners, music centers, televisions, some controlled children's toys also use electromagnetic rays in the infrared range.

The use of infrared rays in the army and space

The most important infrared rays are for the aerospace and military industries. On the basis of photocathodes having a sensitivity to infrared radiation (up to 1.3 microns), night-vision devices (various binoculars, sights, etc.) are created. They allow for simultaneous irradiation of objects with infrared radiation to aim or to observe in absolute darkness.

Thanks to the created highly sensitive receivers of infrared rays, it became possible to manufacture homing missiles. Sensors in their warhead react to infrared radiation from a target, the temperature of which, as a rule, is higher than the environment, and direct the missile at the target. The detection of heated parts of ships, planes, and tanks with the help of heat locators is based on the same principle.

IR locators and rangefinders can detect various objects in total darkness and measure the distance to them. Special devices - optical quantum generators that emit in the infrared, are used for space and distant ground communications.

Infrared radiation in scientific activity

One of the most common is the study of emission and absorption spectra in the infrared region. It is used in studying the features of electron shells of atoms, to determine the structures of all kinds of molecules, and in addition, in the qualitative and quantitative analysis of mixtures of various substances.

Due to differences in the scattering, transmission and reflection coefficients of bodies in visible and infrared rays, photographs taken under different conditions are somewhat different. Pictures taken in the infrared range often show more details. Such images are widespread in astronomy.

Studying the effect of infrared rays on the body

The first scientific evidence on the effect of infrared radiation on the human body dates from 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. In this case, thermoregulation processes similar to the reaction to being in the sauna occur. However, perspiration begins at a lower ambient temperature (it is about 50 ° C), and the heating of internal organs occurs much deeper.

During this heating, blood circulation is strengthened, the vessels of the respiratory organs, subcutaneous tissue and skin expand. However, the prolonged exposure to infrared radiation to humans can cause heat stroke, and strong infrared radiation leads to the appearance of burns of varying degrees.

IR protection

There is a small list of measures aimed at reducing the risk of exposure to infrared radiation on the human body:

1. Decrease in radiation intensity. It is achieved by choosing the appropriate technological equipment, timely replacement of obsolete, as well as its rational layout.
2. Removing workers from the radiation source. If the production line allows, remote control of it should be preferred.
3. Installation of protective screens on the source or workplace. Such fences can be arranged in two ways, allowing to reduce the influence of infrared radiation on the human body. In the first case, they must reflect electromagnetic waves, and in the second, they must be detained and the radiation energy converted into thermal energy with its subsequent removal. Due to the fact that protective screens should not deprive specialists of the ability to monitor processes occurring in production, they can be made transparent or translucent. To do this, silicate or quartz glasses, as well as metal nets and chains, are chosen as materials.
4. Thermal insulation or cooling of hot surfaces. The main goal of thermal insulation is to reduce the risk of workers getting various burns.
5. Personal protective equipment (a variety of overalls, glasses with built-in filters, shields).
6. Preventive actions. If in the course of the above actions the level of exposure to infrared radiation on the body remains quite high, then the 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 oxygen and oxygen saturation of organs and tissues. 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 was noted that surgical operations performed under the influence of infrared radiation have several advantages:

• pains after operations are a little easier;
• faster cell regeneration;
• the influence of infrared radiation on a person allows to avoid cooling of internal organs in the case of surgery on open cavities, which reduces the risk of shock.

In patients with burns, infrared radiation makes it possible to remove necrosis, as well as perform autoplasty at an earlier stage. In addition, the duration of the fever is reduced, anemia and hypoproteinemia are less pronounced, the frequency of complications is reduced.

It is proved that IR radiation is able to weaken the effect of certain pesticides, by increasing non-specific immunity. Many of us know about the treatment of rhinitis and some other manifestations of the common cold with blue infrared lamps.

Harm to humans

It is worth noting that the harm from infrared radiation to the human body can also be very significant. The most obvious and common cases are skin burns and dermatitis. They can occur either when the exposure to weak waves of the infrared spectrum is too long, or during intensive irradiation. If we talk about medical procedures, it is rare, but thermal shock, asthenia and exacerbation of pain occur with improper treatment.

One of the current problems are eye burns. The most dangerous for them are infrared rays with wavelengths in the range of 0.76-1.5 microns. Under their influence, the lens and watery moisture are heated, which can lead to various disorders. One of the most common consequences 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 effect on a certain part of the body is carried out, and in the second case the whole organism is exposed to rays. The course of treatment depends on the disease and can be from 5 to 20 sessions of 15-30 minutes. When carrying out procedures, the use of protective equipment is a prerequisite. To preserve eye health, special cardboard pads or glasses are used.

After the first procedure, redness with fuzzy borders appears on the skin surface, passing about an hour later.

Effect of IR emitters

Given 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 rules. But most importantly, it is important to understand that, like any medical device, infrared emitters cannot be used for a number of diseases.

Therefore, a qualified specialist, an experienced doctor should choose a course of therapy. Depending on the length of the emitted infrared waves, the devices can be used for different purposes.