The main characteristics of electromagnetic radiation

Sources of electromagnetic radiation

It is known that in the vicinity of a conductor through which the current flows electric and magnetic fields are generated simultaneously. If the current does not alternate in time, these fields do not depend on each other. In case of alternating current magnetic and electric fields are interconnected with each other, representing a uniform electromagnetic field.

The electromagnetic field possesses certain energy and is characterized by electric and magnetic strength that is necessary to take into consideration when evaluating working conditions.

Sources of electromagnetic radiation include: radio engineering and electronic devices, inductors, condensers of thermal installations, transformers, antennas, flange connections of wave-guide transmission lines, generators of ultra-high frequencies etc.

Modern geodesic, astronomical, gravimetric, aerophotographic, marine geodesic, engineering-geodesic and geophysical works are carried out with use of devices operating in the range of electromagnetic waves of ultrahigh and extra high frequencies that expose workers to dangers with the rate of radiation up to 10 mcV/cm2.

Biological effect of electromagnetic radiation

A man cannot neither see electromagnetic fields nor feel them and for this reason he doesn’t always protect himself against dangerous effects of these fields. Electromagnetic radiation exerts harmful effect on human body. In the blood, being an electrolyte, under influence of the electromagnetic radiation ionic currents are formed, causing heating of body tissues. At certain intensity of radiation referred to as the thermal threshold, the body can not cope with the generated heat.

Heating is especially dangerous to bodies with underdeveloped vascular system, with no intensive blood circulation (eyes, brain, stomach, etc.). Irradiation of eyes within a long period of time can cause cataract.

In addition to thermal exposure, the electromagnetic radiation exerts adverse effect on the nervous system, causing malfunctions of the cardiovascular system and of metabolism.

Long duration of exposure to electromagnetic field of a man causes undue fatigue, results in decreasing the quality of performance of working operations, strong pains in the heart area as well as in fluctuations of blood pressure and pulse.

The estimation of danger of electromagnetic field exposure of a man is based on the amount of electromagnetic energy absorbed by human body.