1. Introduction

Wireless technologies have become an integral part of people's everyday life, have become familiar and ordinary. The current level of technology development allows using complex high-tech equipment without thinking about how it is designed and how it works. At the current stage of development of new technologies, sources of electromagnetic radiation (EMR) of low intensity (for example, Wi - Fi) are becoming increasingly important. equipment), the influence of which on the life processes of biological objects has not been sufficiently studied [1].

Wi -Fi - is a modern wireless technology for connecting computers to a local network and connecting them to the Internet. It is thanks to this technology that the Internet becomes mobile and gives the user freedom of movement not only within a room, but also around the world [2]. The presence of a large number of such sources is dictated by the development of modern technologies, the transmission of significant amounts of information via wireless communication.

Wi - Fi devices are usually placed in offices, public places, and they are also installed for home use, creating their own wireless networks. Research has established that electromagnetic radiation of the radio frequency range (EMR RF) is one of the serious factors of environmental pollution, causing the risk of adversely affecting the health of the population. Electromagnetic radiation of Wi - Fi devices can affect the biological systems of a warm-blooded organism through thermal or non-thermal effects [3].

When exposed to electromagnetic radiation Wi - Fi equipment in experimental animals, a reliable decrease in the indicators of horizontal and vertical motor activity is observed compared to the control group, which indicates the occurrence of stress in the animals; on the 25th day, a depressive state occurs and there is a slight slowdown in body weight gain [4].

The unique characteristics of wireless device systems include: low equipment cost, high reliability of network solutions, low requirements for the transmission medium, minimal installation and operating costs, ease of marketing, and the ability to use the existing infrastructure of the city telephone network [5,6,7].

Wi - Fi Equipment introduced at the household level or used in places of mass presence of people, as a rule, is characterized by low intensity of EMI, but with its long-term operation, conditions of round-the-clock exposure can be created. The effects of exposure are not always acute, but there are prerequisites for their cumulation and, as a consequence, for the development of remote disorders leading to chronic disorders of a psychofunctional nature [8,10].

The results of studies assessing the effect of wireless network modulation (2.45 GHz) indicate the induction of oxidative toxicity in the laryngeal-tracheal mucosa of rats. The effect of selenium and L -carnitine on the indices of EMI-induced oxidative stress in the blood of rats has been described [9,11].

Electromagnetic radiation with a frequency of 2.4 GHz from wireless networks and working phones affects the autonomic nervous system, causing changes in heart rhythm [12,13].

The influence of the electromagnetic field Wi - Fi has been studied equipment on changes in brain rhythms on EEG depending on gender. The study involved 50 women and 50 men who performed tests aimed at assessing short-term memory. All subjects were exposed to EMF at a frequency of 2.4 GHz. In this case, women, unlike men, showed a decrease in the strength of the alpha and beta rhythm. The differences between men and women were reliable [14].

Similar studies were conducted to assess the impact of Wi - Fi signals on concentration and working memory in a linguistic test in a group of 15 men and 15 women. It was found that the impact of EMF Wi - Fi can lead to changes in neural activity and depends on gender. This is associated with the amount of internal reserves for maintaining focused attention during a linguistic test [15].

2. Materials and Methods

Measurements actual levels of electromagnetic radiation (EMR) of the production environment were conducted in the office premises of communications enterprises in the city of Tashkent. The Wi - Fi standard equipment in the premises was represented by routers: wall-mounted «TP - Link Dego S4R», wall-mounted “TP-Link” with external radiating antennas, ceiling (suspended) mounted “Zyxel”, “Huawei ” and desktop mounted “AIR - AP 1131”.

The studies were conducted at the workplaces of office workers of communications enterprises. To compare the EMI levels at the workplaces, the workers were divided into two groups: the first group (main), whose workplaces were located at a distance of up to 3 meters from Wi -Fi routers (29 workplaces) and the second group (control), employees whose workplaces were located at a distance of more than 3 meters from Wi -Fi equipment (29 workplaces).

The levels of electromagnetic radiation (EMR) at workplaces were measured using the PZ-42 EMR meter, serial number 034, manufactured by Electronpribor CJSC, Russia. The actual levels of electromagnetic radiation were determined at a height of 0.5, 1.0 and 1.2 meters in accordance with the requirements of GOST 12.1.006-84 “Occupational safety standards. Radio frequency electromagnetic fields. Permissible levels at workplaces and requirements for monitoring”. To achieve this goal, 174 measurements of electromagnetic radiation at workplaces were performed.

3. Research Results and Their Discussion

In the process of measuring electromagnetic radiation at work places, conditions were created for maximum hardware power of the transmitter with active radiation of electromagnetic energy by the router into the surrounding space (when transmitting a large volume of information or high-quality video materials to at least 4 receiving terminals simultaneously).

The impact of electromagnetic radiation of Wi - Fi routers on the health of workers in the groups of workers studied was assessed by subjective indicators using a questionnaire based on a specially developed questionnaire. The respondents' answers to the questions posed made it possible to assess the possible adverse impact of electromagnetic radiation of the Wi - Fi standard on the health of workers.

The average age of workers in the main group is 35.3 ± 1.29 years, the average length of service is 12.16 years ± 1.65, in the control group the average age was within 41.17 years ± 1.71, the average length of service was 16.34 ± 2.0, respectively.

Wi -Fi wireless routers at workplaces in office premises of communications enterprises were established (Fig. 1). The average value of the generated parameters of the energy flux density of electromagnetic radiation of Wi -Fi standard equipment at a frequency of 2.4 GHz at workplaces of the first group is 0.77 ± 0.09 μW/cm². At workplaces of workers of the first group at a distance of up to 1 m from the router, the average value of electromagnetic radiation was determined at the level of 1.63 ± 0.04 μW/cm², from 1 to 2 m from the router - 1.11 ± 0.24 μW/cm² and at a distance of 2 to 3 m from the router the EMI levels were 0.51 ± 0.05 μW/cm², respectively.

Figure 1. RF EMR values from Wi-Fi equipment at the workplaces

The average value of the energy flux density levels of electromagnetic radiation at a frequency of 2.4 GHz at the workplaces of the second group of workers is 0.065 ± 0.013 μW/cm².

The surveys showed that 69% of the main group and 72.4% of the control group of respondents have been using Wi - Fi wireless transmission equipment for over 2 years in their work. The work schedule is 8 hours (93.1% and 96.6%, respectively), and the working week for the studied groups of workers is 5 days. 34.5% of the first group and 31% of the second group answered positively to the question about the possible adverse effects of electromagnetic radiation from Wi - Fi equipment on their health and the presence of a possible relationship between the location of wireless communication devices and the distance at which the device is installed.

The results of the questionnaire survey showed that 20.6% of the main and 6.9% of the control group of workers noted the presence of deviations in their health before connecting the equipment of wireless data transmission devices of the Wi - Fi standard, and after connecting, the number of subjective complaints about deterioration in health increased more than twofold and amounted to 48.3% in the main and 10.3% in the control groups of surveyed individuals. The survey of office workers made it possible to establish that 41.4% of the main and 10.3% of the control groups of surveyed individuals indicate an adverse effect of EMF of Wi - Fi equipment on their health, and 17.2 and 10.3% of respondents respectively believe that the reason for the deterioration of their health may be different. At the same time, 41.4% of the main group and 79.3% of the control group of subjects do not associate changes in their health with the impact of wireless data transmission equipment.

4. Conclusions

1. Research has established that the levels of EMR from Wi -Fi wireless system routers at the workplaces of office workers at communications enterprises do not exceed the maximum permissible levels (MPL) established for the premises of public buildings (10 μW/cm²).

2. Wi -Fi standard EMF on the body's condition to be negative, while the number of subjective complaints about deterioration in health has more than doubled after connecting Wi-Fi standard wireless communication devices.

3. To determine the electromagnetic safety of routers of the standard Wi -Fi requires a chronic experiment to study hematological, biochemical, immunological and morphological parameters in experimental white rats under conditions of prolonged exposure to electromagnetic radiation in the radio frequency range.