The effect of a 50 Hz magnetic field on cognitive function in humans.
OBJECTIVE
To examine whether the power frequency magnetic field of 0.6mT applied to humans has an effect on cognitive function as has been suggested by animal studies. These fields are less than the suggested intervention level in the UK of 1.6mT and are similar to those found close to some domestic appliances.


METHODS
A randomized three-way cross-over design using a battery of computerized cognitive function tests were used in the presence or absence of a 50Hz or static magnetic field. Sixteen healthy volunteers undertook two training and three test sessions with a 50Hz or static 0.6 mT magnetic field from a set of coils centred on the head.


RESULTS
In response to the 50 Hz field, disruptions of accuracy were seen from an attentional task (the ability to correctly recognize words shown 20min previously and the ability to maintain a string of digits in working memory). There was no similar response to comparable levels of static magnetic field.


CONCLUSIONS
These tests indicated at least temporary deterioration in attention, and working and secondary memory performance while a 50 Hz field is applied. There were no adverse effects on speed from any of the tasks. It was not possible in this study to be sure if these effects were persistent.
Preece
A W
AW
Department of Medical Physics and Bioengineering, Bristol Oncology Centre, UK.
Wesnes
K A
KA
Iwi
G R
GR
D000328:Adult; D001288:Attention / Q000528:radiation effects*; D003071:Cognition / Q000528:radiation effects*; D018592:Cross-Over Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008280:Magnetics / Q000009:adverse effects*; D008297:Male; D008568:Memory / Q000528:radiation effects; D008875:Middle Aged; D015999:Multivariate Analysis; D011930:Reaction Time / Q000528:radiation effects