Monitoring of the exposure to electromagnetic fields with autonomous probes installed outdoors in

Abstract

Monitoring of the exposure to electromagnetic fields with autonomous probes installed outdoors in France Jawad O, Conil E, Agnani J-B, Wang S, Wiart J. Monitoring of the exposure to electromagnetic fields with autonomous probes installed outdoors in France. Comptes Rendus. Physique, Online first (2024), pp. 1- 21. doi : 10.5802/crphys.182. Abstract The study is based on a new temporal analysis of exposure based on the deployment of autonomous broadband E-field monitoring probes in many French cities. The combination of the probe’s data with frequency-selective in situ measurements performed by ANFR and the knowledge of the nearby base station antennas, allows to draw statistical conclusions on the exposure of the population. Indeed, the data collected by the probes reveal that different periodicities exist (seasonality, day/night). This paper shows that the monitoring probes are able to detect the seasonality of the exposure and provide analysis of correlation between monitoring probes and radio environment. Excerpt The analysis indicates that the monitoring probes have varying exposure levels. Probes measuring significant levels show a difference in exposure between day and night, a phenomenon observed for the first time in France. An empirical time interval from 8 AM to 11 PM enables to calculate the ratio of averaged E-field levels between day and night. This ratio is between 1.28 and 1.42 for the three probes with the highest RMS level. Several papers, such as [8–10], have characterized the day and night fluctuation, but this has never been demonstrated using French data. For the first time, the variability of daily working hours has been quantified for all the probes installed in France. The data shows that most of the probes exhibit a 30% variation percentage based on the data gathered from 8 AM to 5 PM. Based on our knowledge, this is the first time that the assessment of the daily variation contributor based on more than 150 probes installed in different environments is achieved. It confirms the level of daily variation contributor to the in situ measurement uncertainty budget, as communicated in the accredited in situ measurement reports [3, 16, 17].... For the first time, the seasonality of the level of exposure has been analyzed at the French national level. The PCA on dataset No. 2 emphasizes the observation that the positioning of the probe is crucial to observe a remarkable variation of the exposure level. The probe must not only be installed in an area with many base stations, but also in close proximity to them and in a line-of-sight position for the exposure. A large number of probes measuring low exposure levels can be explained by the fact that the probes are not in a line-of-sight situation. In some cities, probes were installed in low-density areas rather than in front of base stations due to public concern over electromagnetic waves. Upon analysis, we find that some probes measure a lower level of exposure in summer time. This interpretation was confirmed with the Principal Component Analysis, which showed that the second component of the PCA characterizes the difference between probes with higher exposure in summer or winter. This phenomenon can be explained by the fact that some of the cities are very touristic during the summer, leading to increased use of the telecommunication infrastructure. In general, the exposure levels measured by the autonomous probe are very low compared to the limits. The increase of the exposure level is relatively slow, as it has been shown in several ANFR studies [4, 18–20]. Open access paper: comptes-rendus.academie-sciences.fr

AI evidence extraction

Main findings

Using autonomous broadband E-field probes deployed in many French cities and combined with frequency-selective in situ measurements and nearby base station information, the study reports detectable periodicities in exposure (day/night and seasonality). For three probes with the highest RMS levels, the day-to-night averaged E-field ratio (8 AM–11 PM vs night) ranged from 1.28 to 1.42; most probes showed about a 30% variation (8 AM–5 PM). Overall, measured exposure levels were reported as very low compared to limits, with relatively slow increases over time.

Outcomes measured

• Outdoor broadband E-field levels (RMS)
• Day/night exposure ratio
• Daily variation during working hours
• Seasonality of exposure
• Correlation between monitoring probes and radio environment

Limitations

• Specific frequency bands and quantitative exposure levels are not provided in the abstract/excerpt.
• Outdoor probe placement (e.g., line-of-sight vs non-line-of-sight) strongly affects measured levels, and many probes measured low levels due to siting.
• Day/night and working-hour analyses rely on empirically chosen time windows (e.g., 8 AM–11 PM; 8 AM–5 PM).
• Findings are based on environmental monitoring and statistical correlations rather than individual-level exposure assessment.

Suggested hubs

• occupational-exposure (0.15)
  Mentions variability during daily working hours (8 AM–5 PM), though the study is not explicitly occupational.

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    "study_type": "exposure_assessment",
    "exposure": {
        "band": null,
        "source": "base station",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Population exposure in many French cities (outdoor monitoring)",
    "sample_size": 150,
    "outcomes": [
        "Outdoor broadband E-field levels (RMS)",
        "Day/night exposure ratio",
        "Daily variation during working hours",
        "Seasonality of exposure",
        "Correlation between monitoring probes and radio environment"
    ],
    "main_findings": "Using autonomous broadband E-field probes deployed in many French cities and combined with frequency-selective in situ measurements and nearby base station information, the study reports detectable periodicities in exposure (day/night and seasonality). For three probes with the highest RMS levels, the day-to-night averaged E-field ratio (8 AM–11 PM vs night) ranged from 1.28 to 1.42; most probes showed about a 30% variation (8 AM–5 PM). Overall, measured exposure levels were reported as very low compared to limits, with relatively slow increases over time.",
    "effect_direction": "unclear",
    "limitations": [
        "Specific frequency bands and quantitative exposure levels are not provided in the abstract/excerpt.",
        "Outdoor probe placement (e.g., line-of-sight vs non-line-of-sight) strongly affects measured levels, and many probes measured low levels due to siting.",
        "Day/night and working-hour analyses rely on empirically chosen time windows (e.g., 8 AM–11 PM; 8 AM–5 PM).",
        "Findings are based on environmental monitoring and statistical correlations rather than individual-level exposure assessment."
    ],
    "evidence_strength": "moderate",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "unknown",
    "keywords": [
        "electromagnetic fields",
        "E-field monitoring",
        "autonomous probes",
        "outdoor exposure",
        "France",
        "base stations",
        "day-night variation",
        "seasonality",
        "PCA",
        "ANFR",
        "radio environment"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.1499999999999999944488848768742172978818416595458984375,
            "reason": "Mentions variability during daily working hours (8 AM–5 PM), though the study is not explicitly occupational."
        }
    ]
}

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