Ph.D., Sapa Vladimir, master student, Nelepin Vladislav

Kostanai State University A. Baitursynov, Kazakhstan

The influence of electric and magnetic fields

on biological objects

Electric and magnetic fields are a factor that has a significant impact on biological objects and, in particular, on the person. Since the evolution of the biosphere occurred under the influence of the fields of natural, biological organisms have a certain level of immunity to electromagnetic fields. However, in the era of science and technology, with the introduction of electric equipment in the industry and the domestic sphere , the increasingly frequent situations in which the human body is exposed to man-made electromagnetic fields, the intensity of which is much greater.

The influence of electric fields can be of great tension personnel working near power lines and ultra-high voltage outdoor switchgear. It was in the course of the operation of these power facilities had experienced a worsening of health personnel whose symptoms were fatigue, headache, sleep disturbances, fatigue. Most sensitive to the effects of this is the human nervous system.

Abnormalities in the nervous system manifested in the work of the cardiovascular system, which is closely related to the nervous system. The symptoms in this case may be arrhythmia, tachycardia, i.e., heart rhythm disturbances due to the distortion control nerve impulses. Nervous and cardiovascular systems of a person are the most sensitive to the effects of external electric and magnetic fields.

However, these fields have an effect on other organs and functions of the human body. There is a violation of metabolism, disorders of the endocrine system, the disease of eye, described the changes of hematopoiesis. The consequence of long associated with professional obligations, stay in electric fields, the strength of which periodically exceeds the permissible limits are the following symptoms: indigestion, and changes in the acidity of gastric juice, functional disorders of the endocrine system, including: increased activity of the thyroid gland, impaired sugar curve; increase the likelihood of developing cancer.

The main cause dysregulation of the various functions of the human body is the effect of electric fields on the nervous system, manifesting as in the effects of excitation and inhibition of its departments. The greatest sensitivity has cerebral cortex - the sphere of higher nervous activity.

The effect of exposure to electromagnetic fields is cumulative and depends not only on the intensity of the field, but also on the time spent in it.

In the zone of influence of the electric field of great tension between man and metal plates potential difference in the following cases: a man isolated from earth (and his body becomes non-zero potential), and the design is grounded (and has the potential of zero), the person is in contact with land and construction - not (such as the car body). In both cases, said potential difference causes that the person in contact with the metallic structure, an electric discharge causes pain when passing discharge current through the body. The greatest danger in the zone of influence of the electric field are isolated from earth metal structures of considerable length or of considerable size. In this case, when you touch them with the person having contact with the ground, there may be current run-off which can cause life-threatening.

To determine the electric field in order to calculate the allowable time remaining in the person required to use devices that measure the current value and provide the necessary measurement range with a tolerance of ± 20%. You can define the vicinity of overhead lines of tension electric transmission and distribution devices by calculation. The residence time is calculated based on the greater of the measured field strength values. Features operating conditions localization rules given in table 1.

Thus, apart from the direct negative impact of a large electric field intensity on the human body hazards are also currents caused by the potential difference that arises in this field. Observations carried out in Sweden for health 500,000 people living in the areas of influence of the magnetic fields of industrial frequency, long-term effect of the field strength of more than 0.3 mT leads to an increase in the frequency of leukemia and cancer.

Table 1 - Features of the working conditions standards localization

Features of operating conditions		The localization of the point of measurement
When working without a lift to the structure or equipment	In the absence of protective equipment	At the height of 1.8 m above ground
	If collective protection	At the height of 0.5, 1.0 and 1.8 m from the ground surface
When working with the rise of the structure or equipment		At the height of 0.5, 1.0 and 1.8 m from the site of the workplace and at a distance of 0.5 m from the grounded parts of the equipment

References:

1. EMC Basics: a textbook for high schools / edited by Doctor of Technical Sciences, Professor RN Karjakin; Alttaysky State Technical University named after II Polzunova. - Barnaul: JSC "Altai Printing Plant", 2007.

2. Habiger E. Electromagnetic compatibility. The basis of its support in technology: Translated from the German / IP Kuzhekin; Edited by BK Maximov. - M. Energoatomizdat, 1995. - 304.

3. Electromagnetic compatibility in power: Textbook / GJ Vaginas, AB Rags, A. A. Sevostianov. - Moscow: Publishing Center "The Academy", 2010. - 224.