Another reader has brought to our attention a fourth paper showing that GSM radiation can alter sleep. James Horne and coworkers at the Sleep Research Centre at Loughborough University in the U.K. have reported that very weak (0.133 W/Kg) signals can delay sleep onset. The new work, published in June, raises some particularly important —and thorny— issues regarding the biological effects of different ELF modulations on the 900 MHz GSM pulses. We'll leave those for another time, but for now the Loughborough study reinforces the take-home message that RF effects on sleep have become a major focus of the mobile phone health controversy.

October 30... One of our alert readers has pointed out that the sleep study we wrote about yesterday has its own Web site. It provides details on members of the research team, their scientific advisors and the study design. The home page includes this message: "Just the increased worry [over RF radiation health risks] might lead to adverse health effects." Maybe so, but given the results recorded so far, this should no longer be a primary concern. We need to redouble our efforts towards getting a better understanding of the health effects of RF energy.

October 29... The ability of mobile phone radiation to affect sleep is emerging as a robust low-level effect.

A team led by Bengt Arnetz has reported that a three-hour exposure to GSM radiation at 1.4 W/Kg an hour before bed can disrupt sleep. This supports the findings of
Peter Achermann of the University of Zurich and Sarah Loughran of the Brain Sciences Institute at Australia's Swinburne University.

Arnetz, who has appointments at both
Wayne State University in Detroit and Sweden's Uppsala University, also found that the GSM radiation can cause headaches, a not infrequent complaint among cell phone users. In a paper presented at the Progress in Electromagnetics Research Symposium (PIERS) in March in Beijing (available online), Arnetz concludes that the radiation affects the "components of sleep believed to be important for recovery from daily wear and tear." Or to put it more simply, using a cell phone can lead to stress.

If you want a good night's sleep, don't spend too long on your cell phone before you go to bed, Arnetz advised the readers of Expressen, one of the two major Swedish tabloids. The story was headlined "
The Mobile Phone Spoils Your Sleep" (October 25).

These new results, while not yet formally published in a peer-reviewed journal, should be taken seriously. First and foremost, this is the third independent finding of an RF effect on sleep —though they are not exact replications, they do complement each other. Second, Arnetz used an average SAR of 1.4W/Kg, which is less than the current U.S. standard of 1.6W/Kg, and well below the ICNIRP limit of 2.0W/Kg, used all over Europe. Third, the mobile phone industry (
MMF) sponsored the study and IT'IS helped design the exposure setup, as it has in most other MMF-funded studies. IT'IS' Niels Kuster has also long collaborated with Achermann. And finally, because Arnetz has a reputation for being an EMF skeptic. In the early 1990s when EMF emissions from computer terminals were a major concern to office workers, Arnetz blamed the mechanization of the modern office environment —or what he called "technostress"— for their health complaints, discounting a possible EMF connection.

Over the last eight years, Achermann has published a
series of papers on the effects of EMFs on sleep. Loughran's paper was published in NeuroReport in 2005. See also a presentation by Arnetz's group from the August PIERS meeting in Prague.