Betreff: Sage Johansson Sage...2007 study re PDA's


Datum: Mon, 27 Aug 2007 13:05:39 EDT





RSS feed for BioelectromagneticsWhat is RSS?

Volume 28, Issue 5 , Pages 386 - 392

Published Online: 13 Mar 2007

Copyright © 2007 Wiley-Liss, Inc.-Wiley-Liss, Inc.




Research Article

Personal digital assistant (PDA) cell phone units produce elevated extremely-low frequency electromagnetic field emissions

Cindy Sage 1 *, Olle Johansson 2, S. Amy Sage 1

11396 Danielson Road, Santa Barbara, California
2The Experimental Dermatology Unit, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden

email: Cindy Sage (

*Correspondence to Cindy Sage, 1396 Danielson Road, Santa Barbara, CA 93108.

Funded by:
 The Swedish Cancer and Allergy Foundation



wireless communication devices • emissions • extremely-low frequency electromagnetic fields • precautionary principle




Initial tests indicate that personal and occupational use of personal digital assistants (PDAs or palm-held wireless units) produce high intensity bursts of extremely-low frequency electromagnetic fields (ELF-EMF). These emissions could result in comparatively high ELF-EMF exposure in persons that carry a PDA close to the body (i.e., in a pocket or on a belt); or held to the head for cell phone conversations. ELF-EMF emissions of 10 µT were recorded on PDAs during normal office use over a 24 h test period. Results of ELF-EMF measurements show that email transmit and receive functions produce rapid, short-duration ELF-EMF spikes in the 2-10 µT range, each lasting several seconds to over a minute apparently depending on file download size. Some units produced spikes as high as 30-60 µT during email activities. Cell phone activity on PDAs produced continuously elevated ELF-EMF readings in the 0.5-1 µT range, as opposed to the rapid spiking pattern for email receipt and transmission. Switching the PDA unit from OFF to ON position resulted in single ELF-EMF pulses of over 90 µT on two units. Email downloads into the PDA can occur randomly throughout the day and night when the unit is ON; thus the user who wears the PDA may be receiving high-intensity ELF-EMF pulses throughout the day and night. The frequency of email traffic on the PDA, and the power switching unit (battery unit) may affect the frequency and intensity of ELF-EMF emissions. Bioelectromagnetics 28:386-392, 2007. © 2007 Wiley-Liss, Inc.

Received: 23 June 2006; Accepted: 20 December 2006

Digital Object Identifier (DOI)

10.1002/bem.20315  About DOI