3,138 Studies Reviewed. 77.4% Found Biological Effects. The Evidence is Clear.

Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers.

Bioeffects Seen

Pedersen C, Poulsen AH, Rod NH, Frei P, Hansen J, Grell K, Raaschou-Nielsen O, Schüz J, Johansen C. · 2017

View Original Abstract
Share:

Utility workers exposed to magnetic fields above 1.0 µT showed up to 78% higher rates of serious neurological diseases.

Plain English Summary

Summary written for general audiences

Danish researchers followed 32,006 utility workers for three decades, studying exposure to magnetic fields from power lines and electrical equipment. Workers with highest exposures showed 44% higher dementia rates and 78% higher motor neuron disease rates, suggesting occupational magnetic field exposure may increase neurological disease risk.

Why This Matters

This study represents one of the most comprehensive investigations into ELF magnetic field exposure and neurological disease to date. The researchers followed utility workers for nearly 30 years, creating a robust dataset that strengthens the case for EMF-related health effects. What makes these findings particularly concerning is that the highest exposure category (≥1.0 µT) represents levels commonly found near power lines and in some occupational settings. The 78% increase in motor neuron disease risk and 44% increase in dementia risk among the most exposed workers cannot be dismissed as statistical noise. While the confidence intervals for some findings include unity, the consistent pattern across multiple neurological conditions suggests a real biological effect. The reality is that this adds to a growing body of evidence linking EMF exposure to neurological harm, yet regulatory agencies continue to focus primarily on heating effects while ignoring these non-thermal biological impacts.

Exposure Details

Magnetic Field
< 0.0001, 0.0001-0.00099 and ≥ 0.001 mG

Exposure Context

This study used < 0.0001, 0.0001-0.00099 and ≥ 0.001 mG for magnetic fields:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: < 0.0001, 0.0001-0.00099 and ≥ 0.001 mGExtreme Concern5 mGFCC Limit2,000 mGEffects observed in the No Concern range (Building Biology)FCC limit is 20,000,000x higher than this exposure level

Study Details

This study updates a previous study of the incidence of such diseases in a large cohort of Danish utility workers by almost doubling the period of follow-up.

We investigated the risks for dementia, motor neurone disease, Parkinson disease, multiple sclerosis...

For dementia, multiple sclerosis and epilepsy the incidence rate ratios (IRR) were close to unity, b...

We observed elevated risks of dementia, motor neurone disease, multiple sclerosis and epilepsy and lower risks of Parkinson disease in relation to exposure to ELF-MF in a large cohort of utility employees.

Cite This Study
Pedersen C, Poulsen AH, Rod NH, Frei P, Hansen J, Grell K, Raaschou-Nielsen O, Schüz J, Johansen C. (2017). Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers. Int Arch Occup Environ Health. 2017 Apr 20. doi: 10.1007/s00420-017-1224-0.
Show BibTeX
@article{c_2017_occupational_exposure_to_extremely_691,
  author = {Pedersen C and Poulsen AH and Rod NH and Frei P and Hansen J and Grell K and Raaschou-Nielsen O and Schüz J and Johansen C.},
  title = {Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers.},
  year = {2017},
  doi = {10.1007/s00420-017-1224-0},
  url = {https://link.springer.com/article/10.1007/s00420-017-1224-0},
}

Quick Questions About This Study

Danish researchers followed 32,006 utility workers for three decades, studying exposure to magnetic fields from power lines and electrical equipment. Workers with highest exposures showed 44% higher dementia rates and 78% higher motor neuron disease rates, suggesting occupational magnetic field exposure may increase neurological disease risk.