IARC classification of radiofrequency fields as Group 2B (2011)

Finding

Group 2B: possibly carcinogenic to humans. The classification rested on limited evidence in humans for glioma and acoustic neuroma among the heaviest users in case–control data, and limited evidence in experimental animals.

What it cannot establish

Group 2B is a statement about the strength of evidence, not about the size of any risk. The same category contains agents whose evidence is weak but not dismissible. The classification does not quantify risk, does not establish causation, and predates the NTP and Ramazzini animal studies and the 2024 WHO-commissioned review.

Related records

• Smartphone (cellular uplink)

  Handsets transmit up to about 200 mW (23 dBm) on cellular uplink and are used against the head, so exposure is governed by SAR — 1.6 W/kg over 1 g in the U.S., 2 W/kg over 10 g under ICNIRP — not by power density.

  Sources & emitters

• INTERPHONE international case–control study (2010)

  The largest case–control study of mobile phone use and brain tumours found no overall increase in glioma or meningioma, with a raised glioma odds ratio confined to the highest decile of reported call time.

  Research record

• WHO-commissioned systematic review of RF exposure and cancer in humans (2024)

  A systematic review and meta-analysis of human observational studies found no association between mobile phone use and brain or head-and-neck cancers, including for long-term and heavy use.

  Research record

Sources

1. iarc-2b-rf IARC classifies radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B), Press Release N° 208 — International Agency for Research on Cancer, 2011. government, link checked 2026-08-12.
2. who-emf-rf Radiation: Electromagnetic fields (questions and answers) — World Health Organization. government, link checked 2026-08-12.