Changes in tympanic temperature during the exposure to electromagnetic fields emitted by mobile phone.

International journal of occupational medicine and environmental health · 2012 · Mixed · Low evidence

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MixedLow evidencePaper 4540

Study snapshot

PublicationInternational journal of occupational medicine and environmental health · 2012

Study typerandomized_trial

Reported directionMixed

Evidence ratingLow

Abstract

OBJECTIVE: Mobile phones generate microwave radiation which is absorbed by exposed tissue and converted into heat. It may cause detrimental health effects. The aim of the experiment was to check if exposure to EMF emitted by mobile phone influenced the tympanic temperature. MATERIAL AND METHODS: Human volunteer study was performed on ten healthy young men, aged 22.1±4.7 years, examined three times: 1. on a day with 2×60 min of no exposure (sham day), 2. on a day with continuous, 60 min exposure and 60 min of no exposure, 3. on a day with intermittent exposure (4×15 min "on" and 4×15 min "off"). Exposure was generated by mobile phone (frequency 900 MHz, SAR 1.23 W/kg). The study was double-blind, performed under controlled conditions (at 24°C and 70% humidity). The tympanic temperature (T(ty)) was monitored every 10 sec by a thermistor probe placed close to the aural canal membrane in the ear opposite the one in contact with mobile phone (contralateral position). Multivariate repeated-measures analysis of variance was used to calculate the results. RESULTS: The mean T(ty) in the whole group during continuous exposure was significantly higher than during sham exposure (p = 0.0001). During intermittent exposure the temperature was lower than during sham day (difference was up to 0.11°C). Within an hour after continuous exposure, T(ty) was higher by 0.03°C and after intermittent exposure T(ty) was lower by 0.18°C in comparison with sham day. Two hours after exposure T(ty) was significantly lower (p = 0.0001) than after sham exposure (0.06°C and 0.26°C respectively). The trends in T(ty) during experiment differed significantly in relation to exposure conditions (p < 0.05). CONCLUSIONS: The results of this analysis indicate that the physiological response to EMF exposure from mobile phone was mostly related to type of exposure (continuous or intermittent).

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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 typerandomized_trial

Effect directionmixed

PopulationTen healthy young men (mean age 22.1±4.7 years)

Sample size10

ExposureRF · 900 MHz · 1.23 W/kg · Continuous 60 min; intermittent 4×15 min on/4×15 min off; sham 2×60 min no exposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Mean tympanic temperature during continuous exposure was significantly higher than during sham exposure (p=0.0001). During intermittent exposure, tympanic temperature was reported lower than during sham (up to 0.11°C difference), and 2 hours after exposure tympanic temperature was significantly lower than after sham (p=0.0001); trends differed by exposure condition (p<0.05).

Outcomes measured

Tympanic temperature (contralateral ear), measured every 10 seconds

Limitations

Small sample size (n=10)
Participants were only healthy young men
Tympanic temperature measured in the ear contralateral to the phone (may not reflect local heating at the exposed ear)

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": 1.23,
    "duration": "Continuous 60 min; intermittent 4×15 min on/4×15 min off; sham 2×60 min no exposure"
  },
  "population": "Ten healthy young men (mean age 22.1±4.7 years)",
  "sample_size": 10,
  "outcomes": [
    "Tympanic temperature (contralateral ear), measured every 10 seconds"
  ],
  "main_findings": "Mean tympanic temperature during continuous exposure was significantly higher than during sham exposure (p=0.0001). During intermittent exposure, tympanic temperature was reported lower than during sham (up to 0.11°C difference), and 2 hours after exposure tympanic temperature was significantly lower than after sham (p=0.0001); trends differed by exposure condition (p<0.05).",
  "effect_direction": "mixed",
  "limitations": [
    "Small sample size (n=10)",
    "Participants were only healthy young men",
    "Tympanic temperature measured in the ear contralateral to the phone (may not reflect local heating at the exposed ear)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "mobile phone",
    "electromagnetic fields",
    "RF",
    "900 MHz",
    "SAR",
    "tympanic temperature",
    "thermoregulation",
    "double-blind",
    "sham exposure",
    "intermittent exposure",
    "continuous exposure"
  ],
  "suggested_hubs": []
}

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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: 10.2478/s13382-012-0013-y
PubMed: 22411069

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