## 1 Introduction  
### Sources of Environmental Radiofrequency EMF Exposure  
Radiofrequency (RF) electromagnetic field (EMF) is commonly used by radio communication systems to transmit information wirelessly. The emitted RF EMF may provide a global range of data exchange (e.g., public mobile communication systems operating over long distances) or only local one (e.g., short range devices operating over distances of up to a several hundred meters, used in applications such as: Internet of Things (IoT), Radiofrequency Identification (RFID) and Wireless Local Area Network (WLAN) equipment) [1; 2; 3; 4]. The area of application of wireless radio communication systems is constantly broadening, which is also increasing the number of RF EMF sources. Devices equipped with wireless functionality connect directly to each other (e.g., in the Wireless Fidelity (Wi-Fi) or Bluetooth systems) or through intermediating networks (e.g., in a network of mobile communication base stations or Wi-Fi access points) [1]. Where there are a large number of subscribers of communication services, e.g., in an urban environment, antennas of mobile communication systems with omni- or directional radiation patterns, which are designed for efficient signal transmission over long distances, are typically located on free-standing masts and roofs of buildings. It is estimated that 5G mobile communication technology enables support for as many as one million devices in an area of 1 km\({}^{2}\)[5]. As a result of using radio communication systems and continuous electromagnetic emissions, in the environment of work and everyday life, virtually everyone is exposed to a RF EMF of complex frequency composition (Figure 1). The typical main radio communication sources of environmental exposure to RF EMF in Poland are characterized in Table 1. Taking into account the high degree of international standardizing in the field of radio communication, a similar frequency pattern of radio communication systems is in other countries. Figure 1: The RF EMF frequency spectrum recorded in the center of Warszawa, Poland, in 2025 [authors archive]. Studies on the health impact of RF EMF emitted by wireless communication systems, which are discussed in the international literature, most often include exposure from mobile phone terminals (local exposure to the user's body at a higher level of RF EMF and a shorter duration than exposure caused by the network of base stations). These studies showed that public exposure to RF EMF may affects brain activity and increase the risk of glioma and acoustic neuroma in the population of heavy users of mobile phones [7]. In most studies, the genotoxic effects of RF EMF exposure at non-thermal levels were not observed, although DNA breaks and mitotic spindle disorders were observed in some cases [7]. Because of harmful health effects (taking long-term and short-term exposure effects into account) various measures are applied to limit RF EMF exposure of workers and the general public. Directive 2013/35/EU requires that workers are protected against electromagnetic hazards [8]. However, in the European Union there are no mandatory requirements regarding protection of the general public against electromagnetic exposure--the Council of the European Union provided limits for general public exposure to EMF as non-mandatory recommendations only [9]. Most of the European Member States have adopted public exposure limits based on these recommendations or have included measures providing for more restrictive protection of the population [10].