# IARC classification of ELF magnetic fields as Group 2B (2002)

> IARC classified extremely low frequency magnetic fields as possibly carcinogenic to humans (Group 2B) on the basis of consistent epidemiological associations with childhood leukaemia above roughly 0.3–0.4 µT.

- Canonical URL: https://emfbase.com/studies/iarc-2002-elf-magnetic-group-2b
- Collection: Research record
- Record id: `studies:iarc-elf-2b-2002`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/studies/iarc-2002-elf-magnetic-group-2b

## Key values

- **Authors:** IARC Monograph Working Group (Monograph 80)
- **Year:** 2002
- **Design:** classification
- **Exposure studied:** Power-frequency (50/60 Hz) magnetic fields, residential time-weighted average exposure
- **Place in the evidence base:** hazard classification
- **Primary document:** https://publications.iarc.who.int/99

## Finding

Group 2B, driven by pooled analyses showing roughly a doubling of childhood leukaemia risk at time-weighted average exposures above 0.3–0.4 µT (3–4 mG), a level reached in only a small percentage of homes.

## What it cannot establish

No established biophysical mechanism at these field strengths, and selection bias and confounding cannot be excluded in the underlying studies. Animal and in-vitro evidence was considered inadequate. The association has not been shown to be causal.

## Related records

- [WHO/IARC ELF magnetic field association threshold (0.3–0.4 µT)](https://emfbase.com/limits/who-elf-0-3-0-4-microtesla-association): The average daily exposure level above which pooled epidemiological studies report an association with childhood leukaemia, and the basis for the IARC Group 2B classification of ELF magnetic fields.
- [High-voltage transmission line](https://emfbase.com/emitters/high-voltage-transmission-line): Fields directly beneath a loaded transmission line reach tens of milligauss and fall off roughly with distance for a balanced three-phase circuit, reaching background at 30–60 m for typical loadings.

## Sources

- `iarc-monograph-80` International Agency for Research on Cancer (2002). *IARC Monographs Volume 80: Non-Ionizing Radiation, Part 1: Static and Extremely Low-Frequency Electric and Magnetic Fields*. https://publications.iarc.who.int/98 — peer-reviewed, link checked 2026-08-12
- `who-elf` World Health Organization (2007). *Electromagnetic fields and public health: exposure to extremely low frequency fields*. https://www.who.int/teams/environment-climate-change-and-health/radiation-and-health/non-ionizing/exposure — government, link checked 2026-08-12
- `ahlbom-2000` British Journal of Cancer (2000). *A pooled analysis of magnetic fields and childhood leukaemia*. https://pubmed.ncbi.nlm.nih.gov/10970686/ — peer-reviewed, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.