(FORTUNE Magazine) – Ross Adey, a distinguished professor of neurology at Loma Linda University School of Medicine, has studied the health effects of electromagnetic fields for more than 30 years. He was interviewed by David Kirkpatrick.

It is not a good thing to proceed toward a world of ubiquitous wireless communication in a totally uncontrolled fashion. The epidemiology suggests that there are health effects that are cumulative over time from exposure to non-ionizing electromagnetic radiation--whether it be 60-hertz power-line fields, today's types of radio and microwave communication, or ultrawide-band technology.

The term "electronic smog" is a good one to describe the ever- increasing amount of this general electromagnetic field exposure. About ten or 15 years ago the Environmental Protection Agency plotted the overall level of man-made electromagnetic fields over time in cities. It went up exponentially.

In a 1987 paper from the National Cancer Institute, a study of microwave workers in the United States, it was clear that certain groups of people who had been exposed for multiple years progressively increased the risk of a brain tumor, up to ten times the levels of a group of people who were not exposed.

An extensive study at a town called Skrunda in Latvia is also very disturbing. The Skrunda area was sprayed by Russian over-the-horizon radar for more than 30 years. The study examined the growth and development of children who were conceived, born, and raised in the path of that signal. There were 900 kids. What they found was that the kids who had been born and raised up to 18 in that beam had defective attention, defective working memory, and defective motor coordination as compared with kids who had not been exposed. The average signal conformed to both U.S. and Soviet safety standards, which are based solely on the heating capacity of the fields. But there are many effects that have been found in animals where the field is not causing any heating.

A nonthermal interaction implies that there is some form of resonant response to the signal by the tissue. We see all sorts of enzyme responses and changes in gene expression if there is a modulation or low-frequency interruption of the electromagnetic signal, whether it be at power-line frequencies or as a modulation of a microwave pulse being turned on and off at a low rate in what might be called a biological spectrum, below 100 hertz.

A study from Brooks Air Force Base published last year showed that ultrawide-band pulses can alter brain chemistry and also change behavior in mice. That study involved tissue energy levels about 100 times below the standard accepted thermal threshold and 1/20th the exposure to tissues in the head from use of a cell phone.

Industry has taken every opportunity to pooh-pooh what is called prudent avoidance. This was evident in the recent reaction to the British Independent Select Committee on Mobile Phones, which said there is a need to avoid excessive exposure to cell phone fields and that children in particular should not be allowed to use cell phones. The industry responded that it had no basis in fact.

There is a big task ahead to define what the lowest level of safe exposure could be. Increasingly, wherever we go, we will be immersed in a sea of low-level, pulsed microwave signals. But there are things we can urge the industry to do. One is that this type of communication should be moved away from the microwave region of the spectrum up into the far infrared, because infrared does not penetrate tissue. This raises technical problems, but more infrared communication is likely to be an imperative if microwave exposure is to be kept at an acceptable level.