RF Safe

Radio-Frequency Electromagnetic Fields: Simultaneous Exposure to Infinite Sources From Typical Base Stations

2021 · No effect · Moderate evidence

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No effectModerate evidencePaper 1032

Using a convergent infinite-series model with real base-station density and conservative path-loss assumptions, the estimated exposure ratio from infinite typical base stations transmitting at multiple bands did not exceed 2.62% of ICNIRP limits for the Brasí…

Study snapshot

Publicationmanual · 2021
Study typeexposure_assessment
Reported directionNo effect
Evidence ratingModerate

Abstract

Radio-Frequency Electromagnetic Fields: Simultaneous Exposure to Infinite Sources From Typical Base Stations A. Linhares, A. P. de Azevedo and L. C. Fernandes. Radio-Frequency Electromagnetic Fields: Simultaneous Exposure to Infinite Sources From Typical Base Stations. IEEE Antennas and Propagation Magazine. doi: 10.1109/MAP.2021.3106829. Introduction This article shows that simultaneous exposure to infinite electromagnetic field (EMF) sources from typical base stations transmitting at multiple frequency bands is lower than international limits. Considering a real base station density and conservative path loss models, we show that the power density at a given location can be modeled by a convergent infinite series. To validate this model, we apply it to Brasília, Brazil, and compare the results with measurements. While the proposed model shows that the exposure ratio (ER) will not exceed 2.62%, the highest measured value reaches 85% of this estimation. Conclusions In this article, we proposed a method to estimate an upper limit for the TER due to infinite sources of typical base stations. When assessing human exposure to RF EMFs due to specific base stations, the exposure caused by all other base stations can be estimated using the model. The model was applied using base station density data from Brasília and shows that simultaneous exposure from infinite cellular macro base stations distributed as shown in Figure 2 will not be more than 2.62% of the ICNIRP limits. It was validated using simulations and more than 3,000 measurements, and our results agree with them regardless of the probe location. However, for a more conservative approach, when assessing individual base stations, the model can be used to estimate an upper limit for all other base stations (i.e., it provides an exposure addition to the results of the base station under test). The model is not bounded to a specific frequency band and generic enough to be used by superimposing different categories of base stations, such as micro and macro cells. It may also be employed for 5G, but due to its antenna beamforming, the approach would be more conservative since RF EMF exposure may decrease due to its dynamic directional characteristics. This topic will be the subject of future studies. To ensure the reproducibility of the results in this article, the equations were implemented in numeric code and are available in [20]. The code and data to generate the results in Tables 1 and 2 and Figures 4, 5, 7, 8, and 9 are also available. ieeexplore.ieee.org

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeexposure_assessment
Effect directionno_effect
PopulationNot supplied
Sample size3000
ExposureRF
Evidence strengthModerateConfidence: 74% · Peer reviewed: yes

Main findings

Using a convergent infinite-series model with real base-station density and conservative path-loss assumptions, the estimated exposure ratio from infinite typical base stations transmitting at multiple bands did not exceed 2.62% of ICNIRP limits for the Brasília, Brazil case study. The model was compared with simulations and more than 3,000 measurements; the highest measured value reached 85% of the model’s estimate, and results were reported to agree regardless of probe location.

Outcomes measured

  • Power density
  • Exposure ratio (ER) relative to ICNIRP limits
  • Total exposure ratio (TER) upper limit from multiple base stations

Limitations

  • Specific frequency bands and exact frequencies are not stated in the abstract.
  • Results are presented for a case study using base-station density data from Brasília, Brazil; generalizability to other settings is not established in the abstract.
  • The model is described as conservative; details of assumptions (e.g., path-loss models) are not fully specified in the abstract.
  • 5G applicability is mentioned as potential/future work; beamforming effects are not directly studied here.
View raw extracted JSON
{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "RF",
    "source": "base station",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": 3000,
  "outcomes": [
    "Power density",
    "Exposure ratio (ER) relative to ICNIRP limits",
    "Total exposure ratio (TER) upper limit from multiple base stations"
  ],
  "main_findings": "Using a convergent infinite-series model with real base-station density and conservative path-loss assumptions, the estimated exposure ratio from infinite typical base stations transmitting at multiple bands did not exceed 2.62% of ICNIRP limits for the Brasília, Brazil case study. The model was compared with simulations and more than 3,000 measurements; the highest measured value reached 85% of the model’s estimate, and results were reported to agree regardless of probe location.",
  "effect_direction": "no_effect",
  "limitations": [
    "Specific frequency bands and exact frequencies are not stated in the abstract.",
    "Results are presented for a case study using base-station density data from Brasília, Brazil; generalizability to other settings is not established in the abstract.",
    "The model is described as conservative; details of assumptions (e.g., path-loss models) are not fully specified in the abstract.",
    "5G applicability is mentioned as potential/future work; beamforming effects are not directly studied here."
  ],
  "evidence_strength": "moderate",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radio-frequency electromagnetic fields",
    "RF EMF",
    "base stations",
    "cellular macro base stations",
    "power density",
    "exposure ratio",
    "ICNIRP limits",
    "infinite series model",
    "measurements",
    "Brasília"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.86,
      "reason": "Exposure estimates are explicitly compared to ICNIRP limits."
    },
    {
      "slug": "5g-policy",
      "weight": 0.28,
      "reason": "5G is mentioned as a potential application, but not directly studied."
    }
  ]
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1109/map.2021.3106829
PubMed: Not supplied

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