INTERACTIVE LESSON & SIMULATOR
Interactive Physics: Power Line Magnetic Field Fall-Off
Plot real-time magnetic field decay curves (1/r vs. 1/r²), test municipal ground current loops, and understand 60 Hz shielding physics.
Where the concern comes from
Starting in the late 1970s, epidemiological studies began finding a modest statistical association between living near high-voltage power lines — specifically, magnetic-field exposure at or above roughly 0.3–0.4 µT — and a higher rate of childhood leukemia in pooled analyses across multiple studies.
How the IARC classification fits
In 2002, IARC classified extremely-low-frequency magnetic fields (ELF-MF) — the type produced by power lines and household wiring — as “possibly carcinogenic to humans” (Group 2B), citing this childhood leukemia pattern specifically. It's the same cautious classification level used for RF fields, and for many other exposures where the evidence is limited and unresolved.
What's still missing
No laboratory or animal study has identified a biological mechanism by which fields this weak could cause cancer, and the elevated-exposure group in these studies is small — well under 1% of children studied. Reviewers have not ruled out that the pattern could reflect something other than the field itself: confounding factors, how cases were selected or reported, or chance.
What this means practically
Major health agencies treat this as an open question worth continued research, not an established risk. If you live near high-voltage lines and want to know your actual field level rather than a distance estimate, a magnetic-field meter reading at the location in question is more informative than either the classification label or general reassurance.