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Source-reviewed evidence brief

Magnetic fields and dementia mortality.

A nationwide Swiss cohort associated long-term modeled exposure from high-voltage power lines with higher mortality from Alzheimer’s disease and other dementias. The study does not establish causation or an individual safe-distance rule.

Written by Dr. Andrie S. Udal PhD, MSHDS, USMDPublished 3 September 2026
An older adult and homes at increasing distances from high-voltage power lines, with magnetic-field contours fading with distance
Illustration: magnetic-field strength generally decreases with distance; contours are not measurements.
Zone 10–49 m
Zone 250–199 m
Zone 3200–599 m
Zone 4600 m or more
The four bands were used in a baseline distance-corridor sensitivity analysis. The primary analysis modeled exposure in microteslas over rolling 10-year residential histories.

The study followed 3,555,064 adults from 2001–2018, covering 55.4 million person-years and 146,655 neurodegenerative-disease deaths. Exposure was estimated from home location, line type, distance, and time at each residence.

The study’s distance corridors

These bands show how the authors tested whether a simpler distance-based analysis agreed with the modeled-exposure results. Because the uploaded main article does not report a numerical hazard ratio for each band, this page does not invent one.

Closest corridor0–49 m

Used in a sensitivity analysis. The main paper says the distance-corridor pattern was consistent with its modeled-exposure analysis.

Near corridor50–199 m

Distance served as a proxy for potential long-term exposure; it was not treated as a biological threshold.

Intermediate corridor200–599 m

The main article does not print a corridor-specific hazard ratio; those estimates are in its supplementary Table S9.

Distant corridor600 m or more

The furthest category in the baseline distance sensitivity analysis, not a guarantee of zero field exposure or zero risk.

Main modeled-exposure results

Hazard ratios below are per 1 µT increase in long-term exposure. That contrast is much larger than the study’s median HVPL exposure of 0.01 µT; only 0.3% of participants had HVPL exposure above 0.30 µT.

Alzheimer’s disease mortality1.5495% CI 1.23–1.92

Higher in the fully adjusted HVPL model

Other dementia mortality1.3195% CI 1.13–1.52

Higher in the fully adjusted HVPL model

Railway-line exposure and Alzheimer’s mortality1.0895% CI 0.99–1.18

Attenuated after environmental adjustment

ALS, Parkinson’s disease, multiple sclerosisNullAcross exposure metrics

No association observed

What “harmful effect” means here

The outcome was mortality recorded on death certificates—not new dementia diagnoses, symptoms, or brain changes. The main association persisted after adjustment for measured social and environmental factors, but observational data can still be affected by residual confounding and exposure error.

Supported

Higher modeled HVPL exposure was associated with higher Alzheimer’s and other-dementia mortality in this cohort.

Not supported

The study found no association for ALS, Parkinson’s disease, or multiple sclerosis.

Unresolved

The authors state that causal inference remains limited by the absence of an established biological mechanism.

Source and editorial note

  1. Sandoval-Diez N, et al. Long-term residential exposure to extremely low-frequency magnetic fields and mortality from neurodegenerative diseases: A nationwide cohort study. Environment International. 2026;208:110145. Read the open-access paper

Source review completed 3 September 2026 from the supplied paper. The illustration is explanatory and not to scale. No independent expert review is claimed. This page is general information, not medical, environmental, property, or legal advice.