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

Authors: Imaida K, Kawabe M, Wang J, Yokohira M, Imai N, Han K-H, Kim Y-B, Jeon SB, Kim HY, Ahn YH

Year: 2026-01-13

Category: Toxicology, Carcinogenicity Research

Journal: Toxicological Sciences

DOI: 10.1093/toxsci/kfag002

URL: https://academic.oup.com/toxsci/advance-article/doi/10.1093/toxsci/kfag002/8423504?searchresult=1

Abstract

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.

radiofrequency radiation mobile phones carcinogenicity genotoxicity animal study rats electromagnetic fields
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