RF Safe

The International Collaborative Animal Study of Mobile Phone Radiofrequency Radiation Carcinogenicity and Genotoxicity: The Japanese Study

Toxicological Sciences · 2026 · No effect · Moderate evidence

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No effectModerate evidencePaper 2451

In male Hsd:Sprague Dawley rats exposed to 900 MHz CDMA-modulated RF-EMFs at whole-body SAR 4 W/kg for 18 h 20 min/day over 2 years, there were no statistically significant increases in neoplastic or non-neoplastic lesion incidences in major organs. Genotoxic…

Study snapshot

PublicationToxicological Sciences · 2026
Study typeanimal
Reported directionNo effect
Evidence ratingModerate

Abstract

Category: Toxicology, Carcinogenicity Research Tags: radiofrequency radiation, mobile phones, carcinogenicity, genotoxicity, animal study, rats, electromagnetic fields DOI: 10.1093/toxsci/kfag002 URL: academic.oup.com Overview The potential carcinogenic and genotoxic effects of radiofrequency electromagnetic fields, particularly those emitted by mobile communication systems, have raised public health concerns. A previous study by the U.S. National Toxicology Program suggested increased incidences of gliomas and cardiac schwannomas in rats exposed to high levels of RF radiation. To evaluate these findings, an international collaborative study was initiated between Japan and Korea. - Study Subjects: Male Hsd:Sprague Dawley® SD® rats - Exposure: 900 MHz CDMA-modulated RF-EMFs; whole-body SAR of 4 W/kg, 18 hours 20 minutes daily over 2 years - Study Components: - 28-day preliminary toxicity study - Genotoxicity assays (alkaline comet and micronucleus tests) - 2-year carcinogenicity assessment - Protocols: OECD guidelines and Good Laboratory Practice adherence Findings - No statistically significant increases in neoplastic or non-neoplastic lesion incidences in major organs (brain, heart, adrenal glands) - Genotoxicity assays revealed no evidence of DNA damage or chromosomal aberrations in RF-exposed rats - Higher survival rate in the RF-exposed group, likely due to lower body weight and food consumption Conclusion This Japanese study, jointly planned and executed by Japan and Korea, provides strong evidence that long-term exposure to 900 MHz RF-EMFs did not produce reproducible carcinogenic or genotoxic effects in male rats. Combined with the Korean study data, these results will contribute to global assessments of the carcinogenic potential of electromagnetic radiation, which remains a key public health consideration.

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 typeanimal
Effect directionno_effect
PopulationMale Hsd:Sprague Dawley® SD® rats
Sample sizeNot supplied
ExposureRF · 900 MHz · 4 W/kg · 18 hours 20 minutes daily over 2 years
Evidence strengthModerateConfidence: 78% · Peer reviewed: yes

Main findings

In male Hsd:Sprague Dawley rats exposed to 900 MHz CDMA-modulated RF-EMFs at whole-body SAR 4 W/kg for 18 h 20 min/day over 2 years, there were no statistically significant increases in neoplastic or non-neoplastic lesion incidences in major organs. Genotoxicity assays (alkaline comet and micronucleus tests) showed no evidence of DNA damage or chromosomal aberrations; survival was higher in the RF-exposed group, attributed to lower body weight and food consumption.

Outcomes measured

  • Carcinogenicity (neoplastic and non-neoplastic lesion incidences in major organs including brain, heart, adrenal glands)
  • Genotoxicity (DNA damage by alkaline comet assay; chromosomal aberrations by micronucleus test)
  • Survival rate
  • Body weight and food consumption (noted in relation to survival)
View raw extracted JSON
{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": 4,
    "duration": "18 hours 20 minutes daily over 2 years"
  },
  "population": "Male Hsd:Sprague Dawley® SD® rats",
  "sample_size": null,
  "outcomes": [
    "Carcinogenicity (neoplastic and non-neoplastic lesion incidences in major organs including brain, heart, adrenal glands)",
    "Genotoxicity (DNA damage by alkaline comet assay; chromosomal aberrations by micronucleus test)",
    "Survival rate",
    "Body weight and food consumption (noted in relation to survival)"
  ],
  "main_findings": "In male Hsd:Sprague Dawley rats exposed to 900 MHz CDMA-modulated RF-EMFs at whole-body SAR 4 W/kg for 18 h 20 min/day over 2 years, there were no statistically significant increases in neoplastic or non-neoplastic lesion incidences in major organs. Genotoxicity assays (alkaline comet and micronucleus tests) showed no evidence of DNA damage or chromosomal aberrations; survival was higher in the RF-exposed group, attributed to lower body weight and food consumption.",
  "effect_direction": "no_effect",
  "limitations": [],
  "evidence_strength": "moderate",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radiofrequency radiation",
    "RF-EMF",
    "mobile phones",
    "900 MHz",
    "CDMA",
    "whole-body SAR",
    "4 W/kg",
    "rats",
    "Sprague Dawley",
    "carcinogenicity",
    "genotoxicity",
    "comet assay",
    "micronucleus test",
    "OECD guidelines",
    "Good Laboratory Practice",
    "international collaborative study",
    "Japan",
    "Korea"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.35,
      "reason": "Animal carcinogenicity/genotoxicity evidence intended to inform global assessments of RF carcinogenic potential."
    }
  ]
}
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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: 10.1093/toxsci/kfag002
PubMed: Not supplied

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