Effect on the human body of ultraviolet radiation
The discovery of infrared radiation prompted the German physicist Johann Wilhelm Ritter to begin studying the opposite end of the spectrum adjacent to his violet area. Very soon it was found out that there is radiation with very strong chemical activity. The new radiation was called ultraviolet rays.
What is ultraviolet radiation? And what is its effect on terrestrial processes and action on living organisms?
The difference between ultraviolet radiation and infrared
Ultraviolet radiation, like infrared, is electromagnetic waves. It is these emissions that limit the spectrum of visible light from both sides. Both types of rays are not perceived by the organs of vision. The differences in their properties are due to the difference in wavelength.
The range of ultraviolet radiation, located between visible and X-ray radiation, is wide enough: from 10 to 380 micrometers (μm).
The main property of infrared radiation is its thermal effect, whereas the most important feature of ultraviolet radiation is its chemical activity. It is thanks to this feature that ultraviolet radiation has a huge impact on the human body.
The effect of ultraviolet radiation on humans
The biological effect exerted by different lengths of ultraviolet waves has significant differences. Therefore, biologists divided the entire UV range into 3 sections:
- UV-A rays, this is the near ultraviolet;
- UV-B - medium;
- UV-C - far.
The atmosphere enveloping our planet is a kind of shield protecting the Earth from the powerful flux of ultraviolet radiation coming from the Sun.
And UV-C rays are absorbed by ozone, oxygen, water vapor and carbon dioxide by almost 90%. Therefore, the surface of the Earth is mainly reached by radiation, containing UV-A and a small fraction of UV-B.
Short-wave radiation is the most aggressive. The biological effect of short-wave UV radiation when hit on living tissues could have a rather destructive effect. But fortunately, the ozone shield of the planet protects us from its impact. However, we should not forget that ultraviolet lamps and welding machines are sources of rays of this particular range.
The biological effect of long-wave UV radiation is mainly in the erythema (causing reddening of the skin) and the effect of the skin. These rays softly affect the skin and tissues. Although there is an individual dependence of the skin on UV exposure.
Eyes can also be affected by exposure to intense ultraviolet light.
Everyone knows about the effect of ultraviolet radiation on a person. But mostly - this is superficial information. Let's try to cover this topic in more detail.
How ultraviolet influences the skin (ultraviolet mutagenesis)
Chronic solar starvation leads to many negative consequences. Just like the other extreme, the desire to acquire a "beautiful, chocolate-colored body" due to prolonged exposure to scorching sunlight. How and why does ultraviolet light affect the skin? What threatens an uncontrolled stay in the sun?
Naturally, reddening of the skin does not always lead to a chocolate tan. Darkening of the skin occurs as a result of the body's production of a pigment that is a pigment - melanin, as evidence of the struggle of our body with the traumatic effect of the UV part of solar radiation. In this case, if redness is a temporary condition of the skin, then the loss of its elasticity, the growth of epithelial cells in the form of freckles and pigment spots is a persistent cosmetic defect. Ultraviolet, penetrating deep into the skin, can cause ultraviolet mutagenesis, that is, damage to skin cells at the gene level. Its most formidable complication is melanoma - a skin tumor. Metastasis of melanoma can lead to death.
Skin protection against UV radiation
Is there skin protection against UV radiation? To protect the skin from the sun, especially on the beach, it is enough to adhere to several rules.
- The pastime in the open sun should be moderate and rational, a light tan obtained at certain hours has photoprotective properties.
- The use of sunscreen should be an integral part of your cosmetic program. When choosing an anti-ultraviolet protection, make sure that it protects your skin from both UV-A and UV-B spectra.
- Use in your diet foods rich in antioxidants and vitamins C and E.
To protect the skin from ultraviolet radiation, you must use specially selected clothing.
How does the ultraviolet affect the eyes (electro-ophthalmia)
Another manifestation of the negative effect of ultraviolet radiation on the human body is electro-ophthalmia, that is, damage to the structures of the eye under the influence of intense ultraviolet radiation.
The disturbing factor in this process is the mid-wave range of ultraviolet waves.
Often this happens under the following conditions:
- during the observation of solar processes without special devices;
- in bright, sunny weather at sea;
- while in a mountainous, snow-covered area;
- at quartz of premises.
With electro-ophthalmia, the cornea burns. Symptoms of such a lesion are:
- increased lacrimation;
- edema of the epithelium of the cornea and eyelids.
Fortunately, usually the deep layers of the cornea are not affected, and after healing of the epithelium, vision is restored.
First aid for electro-ophthalmia
The symptoms described above can bring a person not only discomfort, but also real suffering. How to provide first aid in electro-ophthalmia?
The following actions will help:
- eye wash with clean water;
- instillation of moisturizing drops;
Compresses from wet bags of black tea and raw, grated potatoes perfectly remove the pain in the eyes.
If the help does not work, contact your doctor. He will prescribe a therapy aimed at restoring the cornea.
All these troubles could be avoided using sunglasses with a special marking - UV 400, which completely protect the eyes from all kinds of ultraviolet waves.
Application of ultraviolet radiation in medicine
In medicine, there is the term "ultraviolet starvation." This state of the body occurs when there is no or insufficient exposure to sunlight on the human body.
To avoid the resulting pathologies, use artificial sources of UV radiation. Their dosed use helps to cope with the winter vitamin D deficiency in the body and improve immunity.
In addition, ultraviolet therapy is widely used for the treatment of joints, dermatological and allergic diseases.
Ultraviolet irradiation also helps:
- raise hemoglobin and lower the sugar level;
- improve the thyroid gland;
- restore the work of respiratory and endocrine systems;
- disinfecting effect of UV rays is widely used for disinfection of rooms and surgical instruments;
- its bactericidal properties are very useful for the treatment of patients with severe, purulent wounds.
As with any serious impact on the human body, it is necessary to take into account not only the benefits, but also the possible harm from ultraviolet radiation.
Contraindications for ultraviolet therapy are acute inflammatory and oncological diseases, bleeding, stage II and III of hypertension, active form of tuberculosis.
Every scientific discovery has for humanity both potential dangers and huge prospects for its use. Cognition of the effects of ultraviolet exposure on the human body, allowed not only to minimize its negative impact, but also to fully apply ultraviolet radiation in medicine and other spheres of life.