Estimation of RF and ELF dose by anatomical location in the brain from wireless phones in the MOBI-Kids study

Abstract

Estimation of RF and ELF dose by anatomical location in the brain from wireless phones in the MOBI-Kids study Carolina Calderón, Gemma Castaño-Vinyals, Myron Maslanyj, Joe Wiart, Ae-Kyoung Lee, Masao Taki, Kanako Wake, Alex Abert, Francesc Badia, Abdelhamid Hadjem, Hans Kromhout, Patricia de Llobet, Nadège Varsier, Emmanuelle Conil, Hyung-Do Choi, Malcolm R. Sim, Elisabeth Cardis. Estimation of RF and ELF dose by anatomical location in the brain from wireless phones in the MOBI-Kids study. Environment International. 163. 2022. 107189. doi:10.1016/j.envint.2022.107189. Highlights • Epidemiological studies on mobile phone radiation typically rely on phone use history. • MOBI-Kids is the first study to estimate RF and ELF dose from wireless phones. • RF and ELF doses vary by age, phone model, communication system and amount of use. • Communication system and location in the brain are key determinants of dose. • Duration and number of calls are likely to be crude proxies of dose. Abstract Wireless phones (both mobile and cordless) emit not only radiofrequency (RF) electromagnetic fields (EMF) but also extremely low frequency (ELF) magnetic fields, both of which should be considered in epidemiological studies of the possible adverse health effects of use of such devices. This paper describes a unique algorithm, developed for the multinational case-control MOBI-Kids study, that estimates the cumulative specific energy (CSE) and the cumulative induced current density (CICD) in the brain from RF and ELF fields, respectively, for each subject in the study (aged 10–24 years old). Factors such as age, tumour location, self-reported phone models and usage patterns (laterality, call frequency/duration and hands-free use) were considered, as was the prevalence of different communication systems over time. Median CSE and CICD were substantially higher in GSM than 3G systems and varied considerably with location in the brain. Agreement between RF CSE and mobile phone use variables was moderate to null, depending on the communication system. Agreement between mobile phone use variables and ELF CICD was higher overall but also strongly dependent on communication system. Despite ELF dose distribution across the brain being more diffuse than that of RF, high correlation was observed between RF and ELF dose. The algorithm was used to systematically estimate the localised RF and ELF doses in the brain from wireless phones, which were found to be strongly dependent on location and communication system. Analysis of cartographies showed high correlation across phone models and across ages, however diagonal agreement between these cartographies suggest these factors do affect dose distribution to some level. Overall, duration and number of calls may not be adequate proxies of dose, particularly as communication systems available for voice calls tend to become more complex with time. Conclusion This paper describes the algorithm constructed to assess the localised RF and ELF dose arising from the use of mobile (cellular) and DECT (cordless) phones in the MOBI-Kids study. The algorithm was based on information on phone use provided by study subjects, on information from operators on prevalence of communication systems as a function of time, on RF and ELF modelling performed as part of the exposure assessment work package (which considered morphological changes due to age), and on validation studies performed within the overall study. ELF and RF dose diminished rapidly with increasing depth, demonstrating location in the brain is an important variable in dose estimation. The agreement between CSE and phone use variables varied by communication system; it was highest for GSM and close to 0 for UMTS and CDMA. Higher agreement was observed between CICD and phone use variables, but agreement was still close to 0 for 3G systems. Analysis of cartographies showed high correlation across phone models and across ages, however diagonal agreement between these cartographies suggest these factors do affect dose distribution to some level and should thus be ideally considered. Overall, the results highlight the importance of considering the effect of communication system and anatomical location in estimating dose and suggests phone use is becoming a poorer exposure proxy as communication systems available for voice calls tend to become more complex with time sciencedirect.com

AI evidence extraction

Main findings

The paper describes an algorithm developed for the MOBI-Kids case-control study to estimate localized cumulative RF (CSE) and ELF (CICD) dose in the brain from mobile and cordless phone use. Median estimated doses were higher for GSM than 3G systems and varied considerably by brain location; dose diminished rapidly with increasing depth. Agreement between RF CSE and phone-use variables ranged from moderate to null depending on communication system (highest for GSM and close to 0 for UMTS/CDMA), while agreement between ELF CICD and phone-use variables was generally higher but still close to 0 for 3G systems; RF and ELF dose estimates were reported as highly correlated.

Outcomes measured

• Cumulative specific energy (CSE) in the brain from RF fields
• Cumulative induced current density (CICD) in the brain from ELF fields
• Dose variation by anatomical brain location
• Agreement/correlation between dose metrics (CSE/CICD) and phone use variables (e.g., duration, number of calls)
• Dose variation by communication system (e.g., GSM vs 3G/UMTS/CDMA)
• Dose variation by age and phone model

Limitations

• Sample size not reported in the abstract
• Exposure estimates rely on self-reported phone models and usage patterns
• Algorithm depends on modelling/assumptions and external information (e.g., operator prevalence of communication systems over time) not detailed in the abstract
• No health outcomes are reported; this is an exposure assessment/algorithm paper

Suggested hubs

• mobile-phones (0.9)
  Focuses on RF/ELF dose estimation in the brain from mobile phone use.
• cordless-phones-dect (0.6)
  Includes DECT (cordless) phones as an exposure source.

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    "study_type": "exposure_assessment",
    "exposure": {
        "band": "RF and ELF",
        "source": "wireless phones (mobile and cordless/DECT)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "MOBI-Kids study subjects aged 10–24 years old",
    "sample_size": null,
    "outcomes": [
        "Cumulative specific energy (CSE) in the brain from RF fields",
        "Cumulative induced current density (CICD) in the brain from ELF fields",
        "Dose variation by anatomical brain location",
        "Agreement/correlation between dose metrics (CSE/CICD) and phone use variables (e.g., duration, number of calls)",
        "Dose variation by communication system (e.g., GSM vs 3G/UMTS/CDMA)",
        "Dose variation by age and phone model"
    ],
    "main_findings": "The paper describes an algorithm developed for the MOBI-Kids case-control study to estimate localized cumulative RF (CSE) and ELF (CICD) dose in the brain from mobile and cordless phone use. Median estimated doses were higher for GSM than 3G systems and varied considerably by brain location; dose diminished rapidly with increasing depth. Agreement between RF CSE and phone-use variables ranged from moderate to null depending on communication system (highest for GSM and close to 0 for UMTS/CDMA), while agreement between ELF CICD and phone-use variables was generally higher but still close to 0 for 3G systems; RF and ELF dose estimates were reported as highly correlated.",
    "effect_direction": "unclear",
    "limitations": [
        "Sample size not reported in the abstract",
        "Exposure estimates rely on self-reported phone models and usage patterns",
        "Algorithm depends on modelling/assumptions and external information (e.g., operator prevalence of communication systems over time) not detailed in the abstract",
        "No health outcomes are reported; this is an exposure assessment/algorithm paper"
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "MOBI-Kids",
        "exposure assessment",
        "wireless phones",
        "mobile phones",
        "cordless phones",
        "DECT",
        "radiofrequency",
        "RF",
        "extremely low frequency",
        "ELF",
        "brain",
        "dose estimation",
        "cumulative specific energy",
        "cumulative induced current density",
        "GSM",
        "UMTS",
        "CDMA",
        "3G",
        "laterality",
        "hands-free"
    ],
    "suggested_hubs": [
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            "reason": "Focuses on RF/ELF dose estimation in the brain from mobile phone use."
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}

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