Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study.
van Nierop LE, Slottje P, van Zandvoort MJE, de Vocht F, Kromkout H. · 2011
View Original AbstractStrong magnetic fields measurably impaired brain function by up to 47%, proving electromagnetic fields can directly interfere with cognitive performance.
Plain English Summary
Researchers tested 31 healthy volunteers in a double-blind study to see how magnetic fields from a 7 Tesla MRI scanner affected brain function. They found that exposure to these magnetic fields impaired attention, concentration, and spatial orientation by 5% to 47% depending on the field strength. This demonstrates that even temporary exposure to strong magnetic fields can measurably affect cognitive performance.
Why This Matters
This carefully controlled study provides compelling evidence that magnetic field exposure can directly impair brain function in measurable ways. The researchers used gold-standard methodology - double-blind, randomized, crossover design - to eliminate bias and clearly demonstrate cause and effect. What makes this particularly significant is that these weren't subtle changes requiring statistical gymnastics to detect. We're talking about 5% to 47% decreases in cognitive performance, with attention and spatial processing taking the biggest hits. While 7 Tesla MRI scanners represent extremely strong magnetic fields far beyond everyday exposures, this research establishes a clear biological mechanism: magnetic fields can interfere with normal brain function. The science demonstrates that our nervous systems are not immune to electromagnetic interference, contradicting long-held assumptions about biological effects only occurring at heating levels.
Exposure Details
- Magnetic Field
- 0, 500, 1000 mG
Exposure Context
This study used 0, 500, 1000 mG for magnetic fields:
- 25Mx above the Building Biology guideline of 0.2 mG
- 5Mx above the BioInitiative Report recommendation of 1 mG
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 Details
This study characterises neurocognitive domains that are affected by movement-induced time-varying magnetic fields (TVMF) within a static magnetic stray field (SMF) of a 7 Tesla (T) MRI scanner.
Using a double-blind randomised crossover design, 31 healthy volunteers were tested in a sham (0 T),...
Of the six tested neurocognitive domains, we demonstrated that attention and concentration were nega...
Neurocognitive functioning is modulated when exposed to movement-induced TVMF within an SMF of a 7 T MRI scanner. Domains that were affected include attention/concentration and visuospatial orientation. Further studies are needed to better understand the mechanisms and possible practical safety and health implications of these acute neurocognitive effects.
Show BibTeX
@article{le_2011_effects_of_magnetic_stray_308,
author = {van Nierop LE and Slottje P and van Zandvoort MJE and de Vocht F and Kromkout H. },
title = {Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study.},
year = {2011},
url = {https://oem.bmj.com/content/69/10/759.short},
}