The Assessment of the Influence of Low-Frequency Electromagnetic Fields Originated from the Power Infrastructure on Humans’ Health

Abstract

The objective of this study is to assess the impact of low-frequency electromagnetic fields (LF EMFs) generated by power infrastructure on the nearby environment. Measurements of electric (E) and magnetic (H) field intensities were conducted around high-voltage power lines, transformer stations and facilities related to them. Numerical simulations were also performed to model the distribution of the field values around real buildings in close proximity to power delivery systems. Given the ongoing scientific debate regarding the effects of EMFs on living organisms, the current analysis was based on the existing standards—particularly ICNIRP 2010 guidelines, which set the maximum allowable E and magnetic induction (B) values at 5 kV/m and 200 μT, respectively. Stricter national regulations were also examined, such as Poland’s 1 kV/m E limit in residential areas and Belgium’s 10 μT limit for B. The results showed that while most cases complied with ICNIRP 2010 standards, certain stricter local regulations were exceeded. Specifically, 9 of 14 cases exceeded Poland’s E limits, and 8 failed to meet Belgium’s B requirements. Only in one place—a warehouse near 110 kV power lines (in a critical case)—the ICNIRP limit B was exceeded. These findings underscore the variability in regulatory standards and highlight the need for localized assessments of EMF exposure.

1. Introduction

Over the centuries, humans as biological organisms have lived and developed in an environment in which the electric field (EF) and magnetic field (MF), which are part of the electromagnetic field (EMF), have played and still play a very important role, presenting two pillars sustaining life on Earth. However, since the industrial revolution and the emergence of modern electricity, the inevitable technical and technological progress has been gradually polluting the human environment, exposing humans to various artificial sources of EMFs of the intensities unknown in nature. Further discoveries of electromagnetism and electromagnetic waves attributed to such great names as Oersted, Ampere, Faraday and Maxwell and the invention of the radio as a means of distance communication began the era of the omnipresence of EMFs in the human environment. Nowadays, humans as biological organisms are surrounded by different EFs and MFs emitted from numerous sources of various intensities, such as electrical machines, devices or domestic appliances, not to mention computers, mobile phones, etc.

One of the side effects of each working electrical device is EMFs generated near their workplaces. These fields interfere with various elements of the environment, among which all living organisms are of the greatest concern. Therefore, it is important to accurately determine the nature and the side effects of its impact. Every day, living organisms, including humans, are exposed to the influence of different types of fields of different physical parameters, at a wide frequency (f) range. Electrical devices such as mobile phones, microwave ovens, television or radio transmitters emit electromagnetic radiation (EMR) with a frequency f from 300 MHz to 300 GHz. A portion of this radiation is converted into kinetic energy, which then transforms into heat. This heat can negatively affect health in various ways [1]. On the other hand, the lower frequencies from the radio spectrum frequencies from 100 kHz to 300 MHz range do not cause such phenomena. What should be pointed out is that, during the radiation of high-frequency fields, i.e., above 100 kHz, accompanied with the fields of high intensities, non-ionizing radiation phenomena occur [2,3]. Another type of radiation can be found in the case of low-frequency fields caused by, e.g., power lines (f = 50 Hz or 60 Hz). It is believed that such fields have a quasi-stationary character, and the two components of EMFs, i.e., the electric field (EF) and the magnetic field (MF), can be considered separately [2]. Nowadays, the opinions of the research community about the effects of radiation attributed to different fields on living organisms are divided. This is due to the fact that earlier studies have not unambiguously shown a negative impact of EMFs. Already at the beginning, at the turn of the XIX and XX centuries, there was a widespread view (e.g., in medical textbooks) of the positive impact of EFs and MFs on humans [2]. In the 1950s and 1960s, with the development of science trying to describe the radiation phenomena, this view gradually disappeared, and the view about the neutral effect of EMFs on living organisms began to dominate [2]. The first study that reported the potentially harmful effects of MFs on living organisms was an epidemiological study published in 1979 by Wertheimer and Lepper [4]. In this study, children from the city of Denver, CO, USA, who lived in homes exposed to MFs of higher intensities were tested. This intensity was estimated based on the number of transmission lines near homes and the number of power lines transmitting electricity to homes. It was noted that children exposed to MFs had a “slightly higher” risk of developing leukemia compared to other children who were not exposed to such radiation. The authors developed their own code [5] in which they managed to visually determine the level of this exposure (based on the number of lines in the area of residence). The result of the study raised a lot of controversy, mainly because of the method used in the research, which was very subjective. Nevertheless, it caused an increased interest among researchers in the subject of the influence of EMFs on living organisms, including humans. It should be pointed out that further tests confirmed the validity of the charges against Wertheimer and Lepper after examining children of Rhode Island [6], where no connection between the influence of EMFs and the increase in morbidity was observed. However, different results were obtained by researchers in France and Corsica, who found that people exposed to EMF radiation may be affected by an increased incidence of brain tumors [7]. What is more, it is suggested to be more cautious when it comes to children, as it affects the young nervous system in a more sophisticated manner than an adult one [8]. The National Institute of Environmental Health Sciences [9] modified the method of the analysis by considering the effect of MFs on the basis of the health cards of children, instead of the methodology employed by Wertheimer and Lepper in their study [4], which was based on death certificates. In this study, no negative effects of EMF radiation on health were observed.

However, disturbing results were published by researchers from Sweden [10], who, after examining children up to 16 years of age who, in the 1960s and 1985, lived at a distance of no more than 300 m from power lines (220 kV or 400 kV), observed that the incidents of leukemia were 2.4 times greater than among their peers. Very surprisingly, at the same time, quite opposite results were obtained by researchers from Denmark [11] and Finland [12], who under similar assumptions found no such effects.

A study carried out in California concentrated on the correlation between the distance from the power lines and the effect of magnetic fields on children [13]. The researchers found that neither close proximity to high-voltage lines alone nor exposure to high calculated fields was associated with childhood leukemia.

As we can notice, there have been many studies from 1979 to the present reporting a raised risk for childhood leukemia and tumors with exposure to power-frequency magnetic fields. There are also suggestions that the reported risk is decreasing [14], but there have not been consistent data due to the fact that the results may have been affected by the source of funding [15].

This article considers typical values of electric and magnetic field intensities occurring in the vicinity of power infrastructure. Both direct E and H measurements and their values estimated from numerical simulations for real cases are presented. They all are compared with the limits known from standards and legal regulations in force in various countries.

2. Materials and Methods

Experimental measurements of B were taken using the Spectrum Analyzer Aaronia model NF-5035 (Calderara di Reno, Italy), which is equipped with a three-axis sensor and has the following characteristics: measurement range from 1 pT to 0.1 mT (in the f range from 1 Hz to 1 MHz), measurement error 3%. The value of H was estimated from the well-known equation

$$H={\displaystyle \frac{B}{{\mu }_0}}$$

where μ₀ = 4∙π∙10⁻⁷ H/m is the magnetic permeability of free space, whose value is close to its value for air. In order to determine the value of E, the Spectrum Analyzer Aaronia model NF-5035 was used, which is equipped with a one-axis sensor. This device has a measurement error of 3% in the range from 0.1 V/m to 20 kV/m. All measurements were taken using an instrument placed on a tripod insulated from the ground. The person reading the measurement results stood about 1 m away from the instrument to reduce the impact of their presence on the field distribution. Measurements were conducted at locations reported by employers or investors, which were situated near power lines and electrical installations. The electromagnetic field measurements were performed outdoors or in enclosed spaces—residential buildings, industrial facilities and warehouses—in order to obtain approval for human occupancy for 8 h (industrial areas) or continuous presence (residential locations).

The actual values of E and H were determined using the finite element method by the use of the FEMM 4.2 software for specific boundary conditions. The use of numerical simulations to calculate the distribution of electromagnetic fields has been described in detail, among others, in [16].

3. Results

The results presented in this section originate from expert opinions on potential threats related to the occurrence of EMFs generated by energy infrastructure. The analyzed cases concerned locations in Poland in the case of planned and existing facilities.

3.1. Measurements of the EMF Strength around Energy Infrastructure

In the case of existing energy infrastructure, the simplest solution is often to carry out measurements that show the actual E and B values in a given area. Measurements of actual B values are presented on the example of a 15 kV/0.4 transformer-distribution station located in the basement and on the ground floor of a residential building in the north of Poland. In order to determine the distribution of the MF in the vicinity of the mentioned transformer station, B measurements were carried out, based on which the values of H were estimated. The obtained results are presented in Figure 1. Further investigations focused on the determination of the maximum values of H in the building under consideration as well as in the apartment next to the transformer station. The extremum denoted value of H was 5.3 A/m and 0.4 A/m, respectively. For the purposes of further analysis, exposure to the highest recorded H value was assumed, i.e., 15 A/m (close to the grounding wire of the power transformer).

An example of E measurements is a study conducted on a building plot in northern Poland. An overhead 110 kV line of the following parameters runs over this plot: three AFL-6 240 mm² working cables (L1–L3) and a shield line (LR) with an OPGW 43/22mm²/555 optical fiber with a cross-section of 96 mm². Knowing the parameters of the poles located in the immediate vicinity of the plot (Type P+5, Series S24, and Type ON120+5, Series S24), the minimum height of the wires above the ground was determined, taking into account the cable sag (see Figure 2).

During measurements at a height of 2 m above the ground in the middle of the span, the results were obtained as shown in Figure 3. The coordinates on the x-axis match the data from Figure 2. The maximum value of E is 0.83 kV/m. It should be also mentioned that in a specific position under two line wires placed one above the other, E reaches a value of 0.66 kV/m due to the screening properties of EFs emitted by the wires.

Below is a brief description of other objects examined and the highest measured electric (E_max) and magnetic (H_max) field intensity values, which are listed in

Table 1. The maximum measured values of electric (E_max) and magnetic (H_max) field intensity.

	Investigated Object	Emax [kV/m]	Hmax [A/m]
1	Transformer-distribution station 15 kV/0.4 kV	<0.05	5.3
2	Building plot under 110 kV overhead line (only E)	0.83	-
3	Multi-family building with balconies near 110 kV overhead line	1.2	<0.2
4	Office space with inappropriate equipotential bonding (only H)	-	4
5	Room above the MV/LV indoor station (only E)	4.01	-
6	LV switchboard (only H)	-	<16

:

• A multi-family building with balconies near 110 kV overhead line: Measurements of the vertical component of E were taken under a high-voltage line at a height of 2 m above the ground on a straight line connecting the power pole with the corner of the building, near the pole and on the balcony on the fourth floor. The E values at a height of 2 m above the ground do not exceed 0.5 kV/m. Higher field intensities were measured at a distance of 2 m from the balcony grate, i.e., 1.8 kV/m, and above the balcony balustrade, 1 kV/m;
• An office space with inappropriate equipotential bonding: The highest B values were found in the room near the computer monitor screen (0.58 μT). At a distance of 0.1 m from the monitor surface, the value of B is reduced to 0.3 μT. Higher B values were noted in rooms through which the gas connection made of steel pipe passed. The probable cause of the observed phenomenon was the lack of an insulating insert on the gas connection or incorrectly made equalization connections in the building. The MFs measured directly on the pipe surface outside the building reached B ≈ 5 μT, which is the result of the main frequency current flow;
• A room above the MV/LV indoor station: Measurements were performed on the floor surface above the room where the 15/0.4 kV transformer was installed. The highest H of about 4 A/m was found for f of 50 Hz with a current flow in the order of 200 A in the busbars. The reinforcement elements of the ceiling of the transformer room caused EF to be damped to a level of only 0.005 kV/m;
• An LV switchboard: The MF did not exceed B ≈ 20 μT, which corresponds to H of 16 A/m. The highest field value was measured outside the switchboard cover. The H values above the top and bottom edge of the cover are 8.8 A/m and 12 A/m, respectively. On the other hand, H in front of the computer screen is 3 A/m, and at the window, it is 6 A/m. For comparison, only 0.3 A/m was measured at the entrance door to the room behind which the switchboard is located. This result clearly locates the source of the MF in the switchboard.

3.2. Numerical Simulations of Electric and Magnetic Field Intensities around Energy Infrastructure

The actual values of E and H depend on the configuration of the lines and objects nearby and are usually determined using finite element method calculations in specialized software. Below is an extreme case of the actual implementation of an industrial warehouse located only 4.5 m from the outermost conductors of a two-track 110 kV high-voltage line. Analysis of the field distribution in the FEMM software was performed for specific boundary conditions, i.e., with phase conductors L1 closest to the warehouse walls reaching the highest peak phase voltage value of 100.3 kV, while the remaining phases L2 and L3 reach values of (–50.1) kV. Therefore, all analysis results are given in maximum voltage values related to 1 m. Furthermore, it was assumed that the lightning rod and the construction outline of the proposed warehouse with an external conducting facade have a ground potential of 0 V. Distances between the conductors were determined according to the data for D2 ON and P series poles (Figure 4A). Due to the close proximity of the outer conductors of the overhead line to the structure of the proposed warehouse, to limit corona discharges, it is recommended to round off the side edges, especially where there is proximity to the 110 kV line. In the calculations, this rounding was set at r = 0.2 m. Figure 4B shows the distribution of E at a height of 2.0 m above ground level (E_2m). Because of the shielding of EF by the building structure (Faraday cage), its intensity inside is equal to 0 kV/m.

Figure 5A specifies the values of E on the roof surface and on the side wall of the warehouse. For the analyzed cases, the maximum value of E does not exceed E_max = 4.0 kV/m on the side walls and roof (Figure 5B) and E_2m = 3.0 kV/m at a height of 2.0 m above ground level.

The H value for the 50 Hz component was calculated assuming a restriction based on the occurrence of maximum current values in phases L1, L3 (track 1) and L1 (track 2) located closest to the side plane of the warehouse. According to the obtained data, instantaneous maximum current values of 888.3 A were assumed for phases L1 and L3 (track 1), corresponding to an effective value of 630 A resulting from the assumed long-term load capacity of the conductors for temperatures below 10 °C. In the remaining phases L2 and L3 (track 2), there is a negative instantaneous current value (–444.15 A). To restrict the simulation results, the current value in phase L3 was set to match that of phase L1 for the line closer to the warehouse wall (assumption of a critical asymmetry of load currents resulting in an increase in the magnetic field level). Aluminum lines were assumed, and a 3 mm thick steel sheet was assumed for the warehouse construction to ensure proper mesh generation in the FEMM program. In practice, with smaller steel thicknesses or for other materials, there the attenuation of the MF is smaller, and the field penetrates into the interior of the warehouse. In Figure 6, the distribution of H at a height of 2 m above the ground surface (H_2m) is shown. It is worth noting that, unlike the EF, the MF is able to penetrate the interior of the building under investigation.

Figure 7A determines the H value on the roof surface and on the side wall of the warehouse. In each case, the maximum value of H does not exceed H_max = 125.0 A/m on the side walls and roof (Figure 7B) and H_2m = 96.0 A/m at a height of 2 m above the ground.

In a similar way, numerical simulations were performed for other selected objects. The obtained values of E_max, E_2m, H_max and H_2m are listed in

Table 2. The values of E_max, E_2m, H_max and H_2m obtained from numerical simulations in FEMM software.

	Calculated Case	Emax [kV/m]	E2m [kV/m]	Hmax [A/m]	H2m [A/m]
1	Warehouse hall near 110 kV double-track overhead lines	4.0	3.0	125.0	96.0
2	Multi-family building with balconies near double-track 110 kV overhead lines	3.95	0.89	46.1	12.6
3	Shopping center under 110 kV overhead line	2.2	0.3	46.0	27.0
4	Residential building next to double-track overhead 110 kV lines	2.2	1.25	39.8	48.2
5	Parking under 110 kV overhead line	1.4	0.82	65.0	12.0
6	Terraced buildings near 110 kV double-track overhead lines	1.6	0.9	15.0	15.0
7	Multi-family building with balconies near 15 kV overhead line	0.55	1.3	9.2	4.4
8	Multi-family building under 110 kV overhead line	3.5	0.1	26.1	7.5

. A short characterization of the investigated cases is described below:

• A multi-family building with balconies near double-track 110 kV overhead lines: The analysis was carried out under the following assumptions: the building on the side of the line has balconies placed, according to the design, at a minimum distance of 6 m from the line (horizontal projection). The double-circuit line is characterized by the following technical parameters of poles and conductors (the heights of suspension are given in relation to the base of the poles, taking into account the dimensions of the insulators): OS24 P+5-type poles, a suspension height of the lowest conductor of 19.4 m and a span length equal to 240 m. The minimum suspension height of the lowest phase wire was estimated at 11.9 m. For the line located closer to the building, the maximum phase current value is 460 A. For the other line, the maximum phase current value is 230.0 A;
• A shopping center under a 110 kV overhead line: A commercial building located partially under a high-voltage line with the following parameters: an SW24 ON120+10 pole with a suspension height of the lowest conductor of 23.9 m and an S24 ON120+10 pole with a suspension height of the lowest conductor of 21.8 m. In the analyzed case, the span length was 256.1 m. The value of the long-term current-carrying capacity in the phase cables was 634 A. For the simulation purposes, the maximum permissible cable proximity of 6.4 m to the roof of the building was assumed;
• A residential building next to double-track overhead 110 kV lines: A single-family house located in the vicinity of a 110 kV double-circuit overhead line. The minimum distance of the building wall from the extreme high-voltage line wire is 7.4 m. Line parameters: OS24 P-type pole with a suspension height of the lowest wire of 15 m and OS24 ON150-type pole with a suspension height of the lowest wire of 12 m, a span length is 215 m. The minimum suspension height of the lowest phase wire was estimated at 8.05 m. In order to tighten the simulation results, the highest effective value of the phase voltage of 68.4 kV was assumed in the L1-phase wires (based on energy quality measurements, the average value of the phase-to-phase voltage was 118.4 kV). In the remaining L2- and L3-phase wires, the values then occur at (–34.2) kV. The maximum phase current values for the first and the second circuit are 437.1 A and 310.1 A, respectively;
• Parking under a 110 kV overhead line: Parking for cars and trucks located under a 110 kV high-voltage line with the following parameters: a maximum long-term load capacity of 709 A. The minimum suspension height was determined on the basis of geodetic measurements carried out at a temperature of 2 °C. For phase L1 (–3.37 m from the line axis) and L3 (3.13 m from the line axis), the suspension height was 12.28 m, and for phase L2 (2.32 m from the line axis), the suspension height was determined at 15.76 m. The obtained heights were reduced by a distance of 1.3 m, which results from a higher temperature of the conductor or catastrophic conditions;
• Terraced buildings near 110 kV double-track overhead lines: A residential building located 9 m from the extreme conductor (phase L1) of a double-circuit overhead line with a voltage of 110 kV. The analyzed line section is characterized by the following parameters: an AEG ON-type pole with a suspension height of the lowest conductor of 12.65 m and an AEG O-type pole for which the suspension height of the lowest conductor is 14.75 m (the suspension heights are given in relation to the base of the poles, taking into account the dimensions of the insulators), a span length of 131.14 m. The minimum suspension height was estimated as 9.5 m. A maximum current of 475 A was assumed in each of the line circuits;
• A multi-family building with balconies near a 15 kV overhead line: A residential building constructed 3.8 m from the end pole of the 15 kV MV overhead line. A medium-voltage line terminated with a Kgo-13.5/25 MV cable connection. The long-term load capacity of the investigated line was equal to 280 A;
• A multi-family building under a 110 kV overhead line: A residential building for which the smallest distance to the extreme conductors of the 110 kV HV line is 6.12 m. The analyzed line section is characterized by the following parameters: an SW24 ON120+5-type pole with a suspension height of 70.36 m and an SW24 KN60+10-type pole with a suspension height of 43.58 m (the suspension heights are given in relation to the zero reference level defined by sea level). The minimum suspension height over the analyzed building was estimated as 53.3 m. A maximum current of 675 A was assumed in each of the line circuits.

For the purposes of numerical simulations for the above cases, the following assumptions were made. In the case of 110 kV lines, AFL 6-240-type working conductors with a design diameter of 21.7 mm were used, while for the 15 kV line, the AFL 70 type (diameter equal to 11.3 mm) was employed. Distances between conductors were estimated according to the data for the used poles. The suspension heights of conductors were determined on the basis of the line parameters except in cases where they were measured directly.

4. Discussion

Due to the lack of scientific consensus regarding the impact of EMFs on living organisms, the evaluation of the results described in the previous section was carried out based on the criteria described by the standards. Since there are different standards and local regulations regarding the issue of the allowed values of EMF fields, in order to improve the readability of this article, a subsection relating to this issue is introduced.

4.1. The Overview of Legal Regulations and Standards

The governments of states address the problem of the potential harms of EMFs and introduce some measures of protection in their legislation. One of the legal approaches to ensure no harm to humans happens is the introduction of norms that determine the maximal amount of electric field force or magnetic force that can be emitted by devices that create the field.

There is an independent international body called the International Commission on Non-Ionizing Radiation Protection [17], which was founded in 1992 and issues guidelines regarding the scope of its activities. In 1998, ICNIRP issued a set of guidelines [18] on EMFs and the protection of the general public against their harm. Three physical quantities were analyzed, and their reference levels were established (reference levels are not supposed to be exceeded; sticking to them guarantees no harm to the population); these quantities were E (kV/m), H (A/m) and B (μT); the levels depend on the f (Hz) and are shown in

Table 3. The reference values of E, H and B for EMFs with different f following ICNIRP.

	<1 Hz	1–8 Hz	8–25 Hz	0.025–0.8 kHz	0.8–3 kHz	3–150 kHz	0.15–1 MHz	1–10 MHz	10–400 MHz	400–2000 MHz	2–300 GHz
E [kV/m]	-	10,000	10,000	250/f	250/f	87	87	87/(f0.5)	28	1.375(f0.5)	61
H [A/m]	3.2 × 104	3.2 × 104/(f2)	4000/f	4/f	5	5	0.73/f	0.73/f	0.073	0.0037/(f0.5)	0.20
B [μT]	4 × 104	4 × 104/(f2)	5000/f	5/f	6.25	6.25	0.92/f	0.92/f	0.092	0.0046∙ f0.5	0.20

.

ICNIRP amended its guidelines in 2010 [19] and then further in 2020 [1], allowing for higher reference values. For our further considerations, the f of 50 Hz (standard frequency of electric current) is assumed, and the norms analyzed are for the general public (there also exist norms for professionals working with EMFs, which can be found in the same documents as the ones for the general public). The guidelines’ comparison is in

Table 4. The comparison of guidelines published by ICNIRP.

	1998	2010	2020
Scope of regulation (frequencies)	Up to 300 GHz	1 Hz–100 kHz	100 kHz–300 GHz
Physical quantities regulated	Electric field strength, magnetic field strength, magnetic flux density	Electric field strength, magnetic field strength, magnetic flux density	Electric field strength, magnetic field strength, power density S (W/m2)
E for general public (f = 50 Hz)	5 kV	5 kV	Not affected
B for general public (f = 50Hz)	100 μT	200 μT	Not affected

.

In Europe, the majority of countries’ legislation ought to be consistent with the laws of the European Union. The European Union took a stance on the issue already in 1999 when the recommendation of the European Council on the limitation of exposure of the general public to electromagnetic fields was passed (1999/519/EC [20]). This legal act was inspired by the guidelines of ICNIRP from 1998; it constitutes a framework for all European countries, and among its annexes are the enumeration and definitions of physical quantities that are to be used for EMF evaluation and tables with reference values and formulae for calculations of summary exposure to different EMFs simultaneously. The document itself calls on member states to fulfill important duties concerning the education of the general public about the possible dangers of EMFs, promote research on that topic and ensure the safety of workers exposed to EMFs. The regulations of the EU remain unchanged since their original publication, and the original act is still in force. Different states of the EU may have variations in their legislation (the EU recommendation describes the minimal standards that every country should have implemented, but the member states are free to add additional restrictions or not obey the recommendation). The suggested minimal standards are indicated in Annex B, Table 1 of 1999/519/EC. For the frequency of 50 Hz, the reference values are 5 kV for E and 100 μT for B.

Some countries in Europe have adopted these standards as their own; such examples are Portugal [21], Germany and France [22]. Sometimes, they added some special precautions. For example, in Germany, pursuant to 26. Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes [23] is a list of places (residential buildings, schools, hospitals) where special care should be taken not to exceed the permissible limits. In France, the so-called Abeille law [24] makes it compulsory to provide information on options for exposure reduction and prohibits constant use of Wi-Fi (which is also a type of electromagnetic field) in the presence of children up to the age of 3 years.

Yet another group of countries base their policy on the topic on recommendations or have not legally implemented the recommendation of the EU in their legal systems [25]; in some of these countries, a more lenient set of reference values is used. Among these states are the United Kingdom, Scandinavian countries, Austria and the Netherlands. In the United Kingdom, the National Radiological Protection Board recommends sticking to the values from ICNIRP 1998 [26], but it is not the law. Austria uses the ICNIRP 1998 standard, and in some parts of the country (Salzburg province), pursuant to a law from 2009, additional restrictions have been added that described minimal distance between human dwellings and high-voltage installations [27].

Finally, a group of countries decided to implement their own, stricter regulations: Italy, Belgium, Poland and Switzerland. A summary of their legal solutions concerning EMF protection can be found in

Table 5. The comparison of EMF protection regulation in selected European countries.

Country	Ref.	EMF Restrictions
Italy	[28]	Basic limit as in 1999/519/EC, but in restricted places (schools, nurseries, residential dwellings), allowed B is only 10 μT, new installations are not to exceed 3 μT, and in 3 regions (Veneto, Tuscany, Emilia-Romagna), allowed B is 0.2 μT [29]
Poland	[30]	E of 1 kV and B of 75 μT allowed in residential buildings, E of 10 kV and B of 75 μT allowed in public places
Belgium	[31]	Differences between provinces; the value of E varies between 5 kV and 10 kV; B is reduced in dwellings or house interiors and is usually 10 μT
Switzerland	[32]	Basic limit as in 1999/519/EC, but in new installations and/or objects of “sensitive use”, B allowed is 1 μT

.

This group of states also includes countries that are not members of the European Union—in Serbia, permissible reference values are E of 2 kV and B of 40 μT [33].

Outside Europe, the topic is regulated independently by the states. In the following part of the review, selected examples outside of Europe will be analyzed.

In Canada, the regulations about protection from EMFs are gathered in Safety Code 6 [34] published by the Radiation Protection Bureau of Canada. It provides the norms of exposure both within the body and (in the form of reference levels) in the environment. The scope of this regulation encompasses f from 3 kHz to 300 GHz. As for the f of 50 Hz, Canada does not have any national regulation, but in practice, ICNIRP guidelines are used [35].

In the United States, there are no federal regulations concerning reference levels or restrictions to EMFs. This matter was left to the states, and some of them introduced their own regulations and limits for EMF exposure—some states chose not to establish any limit value and focused on precautions to avoid excessive exposure, e.g., by establishing minimal distances between installations and human dwellings; in other states, there are limits established, and they range between 20% and 240% of ICNIRP depending on the state [25].

Japan has a standard regulated by the Ordinance of the Ministry of Economy, Trade and Industry, in which the limit of E = 3 kV and of B = 200 μT are established [36].

China has its own reference set of values, which are regulated mostly by Chinese norms GB 8702-88 [37] and GB 9175-88 [38]. They are lower than EU/ICNIRP standards [18,39] with percentage differences differing depending on f [40]—up to 800 Hz, they are mostly concordant with the EU standard; at higher f, they are lower than ICNIRP. Australia also does not have any national standard, but the country’s authorities decided to use the guidelines from ICNIRP.

The reference limit values for 50 Hz EMFs defined by different standards and local regulations are summarized in

Table 6. The reference limit values for 50 Hz EMF following different standards and local regulations.

	ICNIRP 1998	ICNIRP 2010	1999/519/EC	Portugal	Germany	France	Belgium	Italy	Poland	The Netherlands	Switzerland	UK	Spain	Canada	USA	Japan	China	Australia
E [kV/m]	5	5	5	5	5	5	5–10 1	5	1/10 2	5	5	5	5	5	1–12 1	3	4	5
B [μT]	100	200	100	100	100	100	10	3–100 1	75	100	1/100 3	100	100	100	-	200	100	100
H [A/m]	80	160	80	80	80	80	8	2.4–80 1	60	80	0.8–80 3	80	80	80	-	160	80	80

¹ Differences between provinces/states. ² Residential buildings/other buildings. ³ New installations and objects of “sensitive use”/basic limit.

.

4.2. The Impact of LF EMF on Humans

The cases described in Section 3 were assessed for compliance with various EMF limit standards and regulations applicable in selected countries. The obtained results are presented in

Table 7. Compliance of the examined cases with various standards and legal regulations regarding electromagnetic field limits.

		Standards			Local Regulations
		ICNIRP 1998	ICNIRP 2010	1999/519/EC	Belgium	Italy	Switzerland	Poland	Japan	China
Measurements	Transformer-distribution station 15 kV/0.4 kV	YES	YES	YES	YES	NO 1	NO 2	YES	YES	YES
	Multi-family building with balconies near 110 kV overhead line	YES	YES	YES	YES	YES	YES	NO	YES	YES
	Building plot under 110 kV overhead line (only E)	YES	YES	YES	YES	YES	YES	YES	YES	YES
	Office space with inappropriate equipotential bonding (only H)	YES	YES	YES	YES	NO 1	NO 2	YES	YES	YES
	Room above the MV/LV indoor station (only E)	YES	YES	YES	YES	YES	YES	NO	NO	NO
	LV switchboard (only H)	YES	YES	YES	NO	NO 1	NO 2	YES	YES	YES
Numerical simulations	Warehouse hall near 110 kV double-track overhead lines	NO	YES	NO	NO	NO	NO	NO	NO	NO
	Multi-family building with balconies near two 110 kV overhead lines	YES	YES	YES	NO	NO 1	NO 2	NO	NO	YES
	Shopping center under 110 kV overhead line	YES	YES	YES	NO	NO 1	NO 2	YES	YES	YES
	Residential building next to double-track overhead 110 kV lines	YES	YES	YES	NO	NO 1	NO 2	NO	YES	YES
	Parking under 110 kV overhead line	YES	YES	YES	NO	NO 1	NO 2	NO	YES	YES
	Terraced buildings near 110 kV double-track overhead lines	YES	YES	YES	NO	NO 1	NO 2	NO	YES	YES
	Multi-family building with balconies near 15 kV overhead line	YES	YES	YES	NO	NO 1	NO 2	NO	YES	YES
	Multi-family building under 110 kV overhead line	YES	YES	YES	NO	NO 1	NO 2	NO	NO	YES

¹ Applies to provinces with the most restrictive regulations. ² Applies to new installations and objects of “sensitive use”. In other cases, the requirements are met.

. It can be observed that the current version of standard ICNIRP is less restrictive in the context of the maximum permissible values of H than the older one. For this reason, all of the investigated cases obey limitations imposed by ICNIRP 2010. Nevertheless, it should be mentioned that there was only one case (warehouse hall near the 110 kV double-track overhead lines) when the requirements of ICNIRP 1998 [18] and 1999/519/EC standards were not met. Local legal regulations proved to be more demanding in terms of permissible exposure to EMFs. For example, the limit for H in Belgium is one order of magnitude smaller than the value defined by the ICNIRP 2010 standard, which is why most of the investigated cases are not in line with these requirements. In the case of Italy, the failure to meet local EMF requirements concerns in most cases the lowest limits of H, which apply only in selected provinces. The situation is similar in Switzerland, but the restrictions imposed mainly apply to new installations and objects of “sensitive use”. Polish regulations are distinguished by a very low permissible E value, which is equal to 1 kV/m for residential areas, and a reduced permissible value of B = 75 μT compared to standard ICNIRP 2010. The above restrictions mean that the construction of residential buildings under high-voltage lines or in their immediate vicinity is significantly limited. The restrictions on the maximum allowable value of E in Japan and China are also more restrictive than those defined by the ICNIRP 2010 standard, which is why (especially in the first case) some of the facilities considered did not meet their requirements. Among the cases analyzed, the most problematic in terms of compliance with the above-mentioned requirements was the case of the warehouse hall near the 110 kV double-track overhead lines.

5. Conclusions

The overall objective of this article was to estimate the impact of LF EMFs generated by power infrastructure. For this purpose, there were analyzed values of E and B obtained during measurements on objects localized in the neighborhood of HV power lines, transformer stations, etc. Furthermore, numerical simulations of the distribution of the EF, as well as MF distributions, around real buildings next to power delivery system elements were conducted. To date, it has not been clearly established to what extent EMF radiation affects the development of cancer in humans. These concerns have prompted calls for the IARC [41] to reassess the risks of RF radiation. The results of animal studies suggest the need to consider upgrading the classification to “probably carcinogenic” or higher [42]. Given the lack of scientific consensus on the impact of EMFs on living organisms, the evaluation of the obtained results was based on the criteria outlined in existing standards. Various standards and local regulations address the permissible levels of EMF exposure. The guidelines included in the ICNIRP 2010 standard were chosen as the basic reference point, defining the maximum permissible values of E = 5 kV/m and B = 200 μT. Compared to the previous version of this standard from 1998, the permissible value of B has been doubled. However, individual countries may introduce stricter limits on these amounts. In terms of permissible limits of E, the most restrictive requirements among the analyzed examples were those of Polish regulations (1 kV/m in the case of residential areas). In the matter of permissible values of B, Belgium has introduced the most restrictive regulations (B = 10 μT). Nevertheless, some countries introduce even lower limits of E and B, but this only applies to selected aspects, e.g., the B limit in some Italian provinces has been reduced to 3 μT. Another example is Switzerland, where new installations and objects of “sensitive use” require B smaller than 1 μT. Of the cases examined, only one (warehouse hall near the 110 kV double-track overhead lines) did not meet the requirements set by standard ICNIRP 2010. Due to the lowest permissible B values, 8 of the 14 cases analyzed did not meet the requirements set by Belgian regulations. In light of the regulations in force in Poland, and especially the low permissible E values, the established limits were exceeded in nine cases.

Numerical simulations performed using FEMM software showed that the value of the E strongly depends on the distance from the source (in this case, from the 110 kV double-track overhead lines). At distances greater than 30 m from the chosen reference point, this parameter did not exceed the background level. Based on these simulations, it can also be concluded that a building wall made of steel with a thickness of at least 3 mm is sufficient to provide shielding from the EF. In the case of reinforced concrete structures, the so-called Faraday cage effect will also be observed. However, it should be noted that the MF is capable of penetrating through building walls. Actual EMF values depend on many factors, such as the configuration of the high-voltage line wires, the design of the pole, the type of wires used and the maximum voltage and current flowing through them. Therefore, it is advisable to measure the actual EMF levels with appropriate instruments once the construction process is complete.