Measurement of non-ionizing radiation (NIR) from Wi-Fi access points and microwave ovens in

Abstract

Measurement of non-ionizing radiation (NIR) from Wi-Fi access points and microwave ovens in residential environments Silva, J. da L. A., Rodrigues, M. E. C., Pinheiro, F. S. R., Silva, G. S. da, Mendonça, H. B., Silva, R. Q. de F. H., ... Sousa, V. A. de, Jr. (2025). Measurement of non-ionizing radiation (NIR) from Wi-Fi access points and microwave ovens in residential environments. Journal of Electromagnetic Waves and Applications, 1–22. doi: 10.1080/09205071.2024.2449120. Abstract It is essential to monitor the radiation levels to which the general population may be exposed and compare them to limits established by national and international standards. This is especially true in residential environments, where there is a consolidated use of microwave ovens and Wi-Fi access points, in addition to the short distances devices can be from the user, as well as prolonged periods of user exposure. The objective of this work is to measure the exposure levels for daily Wi-Fi and microwave oven use scenarios in residential environments, to compare measured levels with the standards and to verify possible relation with the characteristics of the equipment under analysis. We use the Narda NBM-520 to support our measurements, the same equipment the National Telecommunication Agency (ANATEL) uses for Brazil's Non-ionizing Radiation (NIR) inspection. This work presents measurements in 40 Wi-Fi access points in which the highest exposure level was 4.66V/m (7.64 % of the limit), verified for the 2.4 GHz network (the so-called Situation 1). This work also presents measurements in 50 microwave ovens. It was observed that 72% of them had the highest level of exposure for the position in front of the door. Conclusion This work evaluates the level of exposure to NIR in homes, mainly from technologies commonly found in residences: Wi-Fi and microwave ovens. For this, measurements were performed on 40 Wi-Fi access points and 50 microwave ovens following measurement methodologies from suitable governmental agencies. For Wi-Fi case study, the influence of electric field levels was investigated in four measurement situations, by equipment brand, and by time of use. The highest level of exposure was verified for the 2.4 GHz loaded network (Situation 1), at a value of 4.66V/m (7.64% of limit). As for the influence of the brand, the variation of the equipment model between the samples impacts the dispersion of the data; so Brand 4, which has the highest dispersion, has four different models and only two samples of identical models, while Brands 1 and 2 had the lowest dispersion and contain most of the samples belonging to the same model. Thus, no clear relation was observed regarding the year of acquisition of Wi-FI APs and the NIR leakage. The microwave oven case study targets the relation between power density level and position, brand, time of use, and conservation. We observe that 72% of the samples had the highest level of exposure in front of the door, followed by 18% on the left side (considering the observer facing the microwave oven as a reference). We speculate that the ventilation outlet located at the left side is responsible for some NIR leakage, since 2 of 3 samples that presented the worst point at the top of the oven, the ventilation outlet is located in this local Our results do not show the influence of the brand on the power density levels. However, regarding the time of use, there is a tendency for microwave ovens to reach higher levels of power density with age, since microwave ovens with year of acquisition <2016 (oldest) present the highest levels. Likewise, the state of conservation of the equipment restrained the levels of power density so that all microwave ovens that reached an average power density above 0.6W/m2 showed signs of use. In addition, only two of the nine ovens that obtained peak power above 1W/m2 did not show signs of use. tandfonline.com

AI evidence extraction

Main findings

Measurements were performed on 40 Wi‑Fi access points and 50 microwave ovens in residential environments using a Narda NBM-520. For Wi‑Fi, the highest exposure level reported was 4.66 V/m (7.64% of the limit) for the 2.4 GHz loaded network scenario. For microwave ovens, 72% had the highest exposure level at the position in front of the door; brand was not associated with power density levels, while older acquisition year (<2016) and signs of use were associated with higher power density levels (as described as a tendency).

Outcomes measured

• Electric field strength (V/m) from Wi‑Fi access points
• Power density levels from microwave ovens
• Comparison to national/international exposure limits/standards
• Association of measured levels with equipment characteristics (brand/model, time of use/age, conservation state, position around device)

Limitations

• No health outcomes assessed; study focuses on exposure measurements and comparison to limits
• Specific standards/limits referenced are not named in the abstract
• Measurement distances, durations, and detailed protocols for the four Wi‑Fi situations are not provided in the abstract
• Microwave oven frequencies and absolute exposure values are only partially reported (e.g., thresholds/peaks mentioned without full distribution)
• Some interpretations are speculative (e.g., ventilation outlet as leakage source)

Suggested hubs

• school-wi-fi (0.25)
  Includes Wi‑Fi exposure measurements, though conducted in homes rather than schools.

{
    "study_type": "exposure_assessment",
    "exposure": {
        "band": "microwave",
        "source": "wi-fi, microwave oven",
        "frequency_mhz": 2400,
        "sar_wkg": null,
        "duration": "daily use scenarios in residential environments; prolonged periods mentioned (no quantified duration)"
    },
    "population": "General population in residential environments (homes)",
    "sample_size": 90,
    "outcomes": [
        "Electric field strength (V/m) from Wi‑Fi access points",
        "Power density levels from microwave ovens",
        "Comparison to national/international exposure limits/standards",
        "Association of measured levels with equipment characteristics (brand/model, time of use/age, conservation state, position around device)"
    ],
    "main_findings": "Measurements were performed on 40 Wi‑Fi access points and 50 microwave ovens in residential environments using a Narda NBM-520. For Wi‑Fi, the highest exposure level reported was 4.66 V/m (7.64% of the limit) for the 2.4 GHz loaded network scenario. For microwave ovens, 72% had the highest exposure level at the position in front of the door; brand was not associated with power density levels, while older acquisition year (<2016) and signs of use were associated with higher power density levels (as described as a tendency).",
    "effect_direction": "unclear",
    "limitations": [
        "No health outcomes assessed; study focuses on exposure measurements and comparison to limits",
        "Specific standards/limits referenced are not named in the abstract",
        "Measurement distances, durations, and detailed protocols for the four Wi‑Fi situations are not provided in the abstract",
        "Microwave oven frequencies and absolute exposure values are only partially reported (e.g., thresholds/peaks mentioned without full distribution)",
        "Some interpretations are speculative (e.g., ventilation outlet as leakage source)"
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "non-ionizing radiation",
        "NIR",
        "Wi-Fi",
        "2.4 GHz",
        "microwave ovens",
        "residential exposure",
        "electric field",
        "power density",
        "Narda NBM-520",
        "ANATEL",
        "exposure limits"
    ],
    "suggested_hubs": [
        {
            "slug": "school-wi-fi",
            "weight": 0.25,
            "reason": "Includes Wi‑Fi exposure measurements, though conducted in homes rather than schools."
        }
    ]
}

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