Solar radiation – emitted by the sun this whole stream of radiation. It represents the electromagnetic waves of different wavelengths. In respect of hygiene for the people of particular interest is part opricheskaya sunlight. It occupies a range from 280 – 2800 nanometers. Longer waves – radio waves and shorter – gamma-rays do not reach the earth's surface, as trapped in the upper atmosphere.

The intensity of the sun in the first turn depends on the sun above the horizon. If the sun is at its highest point of the horizon, the path traversed by the sun's rays will be much shorter. By increasing the path of solar radiation changes. It also depends on the angle of the sun. Depends on it, and the illuminated area of the sun. Thus, the same solar radiation falls on the large surface area, so the intensity decreases.

Statement intensity of solar radiation also depends on the mass of air through which the sun's rays. In this regard, her testimony in the mountains will be higher than above sea level. After all, the air layer through which the sun's rays will be less than above sea level. Of particular importance is the effect on the intensity of solar radiation by atmospheric conditions and pollution. In the polluted atmosphere of its readings decrease. For example, in the city it is about 10% less than in rural areas. Intensity of solar radiation has an annual and daily background. It varies during the day and depends on the season. The highest intensity is observed in summer and lowest in winter. According to their biological attack is not uniform. Each wavelength has a different effect on the person. The solar spectrum can be divided into 3 sections: 1. Ultraviolet rays have wavelengths from 280 to 400 nanometers. It most active in terms of biological part of the solar spectrum.