Assessment of the Variability of Human Exposure to Radiofrequency Electromagnetic Fields Arising from 5.9 GHz Vehicular Communication in Urban Environments

Abstract

This paper assessed the variability of radiofrequency exposure among road users in urban settings due to vehicle-to-vehicle (V2V) communication operating at 5.9 GHz. The study evaluated the absorbed dose of radiofrequencies using whole-body specific absorption rate (SAR) in human models spanning different age groups, from children to adults. To overcome limitations of previous studies, we developed a novel hybrid procedure that combines deterministic and stochastic approaches, enabling assessment across multiple urban layouts. Real urban conditions and varying propagation scenarios were considered in SAR calculations. By varying the road user’s position within 1.5–300 m from transmitting cars, the SAR distribution was determined. Median SAR remained consistently low, around 0.70 mW/kg, even with multiple transmitting cars and multiple emitting antennas, using maximum power allowed in US (44.8 dBm). The 99th percentile of SAR distribution varied based on body mass, decreasing for heavier models (typically adults) and increasing with the number of transmitting cars and antennas. The highest absorbed dose (73 mW/kg) occurred in a child model. The SAR consistently remained below the 80 mW/kg limit for whole-body exposure to electromagnetic fields in the 100 kHz–300 GHz range.

Evaluation of Road User Radio-Frequency Exposure Levels in an Urban Environment From Vehicular Antennas and the Infrastructure in ITS-G5 5.9 GHz Communication

“…To the best of our knowledge, this is the first study that assessed the exposure levels generated by both V2V and V2I technologies. Other articles in the literature evaluated the exposure levels generated by V2V antennas at 5.9 GHz [16]- [21] and for the recent 5G-V2V technology operating at 3.5 GHz [19][20]. Specifically, the authors in [17][18] investigated the exposure levels generated by 5.9 GHz V2V technology through a deterministic approach on an adult [17] and children [18] placed in close proximity to the vehicle.…”

“…Differently from [16]- [18], the authors in [21], investigated the exposure levels generated by V2V technologies using an analytical approach to account for the variability of V2V exposure in urban scenarios of different characteristics. To provide a meaningful numerical comparison, we focused only on the data of [21] obtained from scenarios that look the most similar to our owns.…”

“…In all these studies there was evidence that the dose absorbed by the human body was always below the basic restriction of the ICNIRP [22] and IEEE [23] guidelines of 0.08 W/kg in the overall body, and 2 W/kg in 10 g of tissues in the head and torso region, and 4 W/kg in 10 g tissues of the limb region. In contrast to the previous articles that examined the exposure levels of road users in free space [16]- [20] and, in the best case, using an analytical approach that accounts for the influence of buildings and roads on the propagation of the RF field generated by vehicular antennas [21], this current study wants to consider a more realistic urban scenario that includes 3D models of all the most characteristic features seen in a real urban environment, i.e., buildings, roads and vegetation like trees and grass. Furthermore, while most of the attention in the previous studies was placed on V2V technology [16]- [21], nothing is known about the exposure levels emitted by other V2X technologies, for example by the infrastructure, i.e., by V2I communication.…”

“…In contrast to the previous articles that examined the exposure levels of road users in free space [16]- [20] and, in the best case, using an analytical approach that accounts for the influence of buildings and roads on the propagation of the RF field generated by vehicular antennas [21], this current study wants to consider a more realistic urban scenario that includes 3D models of all the most characteristic features seen in a real urban environment, i.e., buildings, roads and vegetation like trees and grass. Furthermore, while most of the attention in the previous studies was placed on V2V technology [16]- [21], nothing is known about the exposure levels emitted by other V2X technologies, for example by the infrastructure, i.e., by V2I communication. For this reason, in this study, we investigate the exposure levels of road users in a realistic urban vehicular scenario that includes not only V2V but also V2I communication technologies.…”

“…In [19] [20] the authors investigated the exposure levels on a road user generated by V2V technology at 3.5 GHz (considering the C-V2X protocol) with both deterministic [19] and stochastic methods [20]. Finally, the authors in [21] investigated the dose absorbed generated by the V2V technology at 5.9 GHz on a road user considering additional factors to mimic an urban layout composed of buildings and roads. In all these studies there was evidence that the dose absorbed by the human body was always below the basic restriction of the ICNIRP [22] and IEEE [23] guidelines of 0.08 W/kg in the overall body, and 2 W/kg in 10 g of tissues in the head and torso region, and 4 W/kg in 10 g tissues of the limb region.…”