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Why, in My Lab, a Grandmother's Clock Is More Useful Than a Stopwatch

Masumi Yamashita
Department of Geophysics
Stanford University
March 2002


Are electromagnetic fields (EMF) in our daily lives hazardous to our health? To answer this question, scientists have been conducting laboratory tests for decades. But test results from different researchers often do not agree. We cannot be sure whether EMF effects exist or not, and if they do, how, and to what degree, unless experimental results are consistent. I looked for ways to improve consistency of test results. Using water as the test substance, I found that data are more consistent if we measure properties over days, rather than just for minutes or even hours.

Life on Earth has evolved for more than 4 billion years in the presence of natural electromagnetic, magnetic, and electric fields, generated by the earth, or coming from other parts of the universe. About a hundred years ago, human beings developed electricity, and our life quickly became dependent on electrical devices. Today, all of us depend on electrically, magnetically, or electromagnetically operated devices, including computers, clocks, radios, TVs, cars, refrigerators, and lights. Electromagnetic fields (EMF) from these devices are inescapable. Even the air of remote woods is permeated by electromagnetic waves that come from various radio stations, cell phone towers, satellites, etc. These waves even pass through our bodies, 24 hours a day, and the total exposure level is increasing daily.

This is the first time in human history that we have been exposed to EMF so continuously. So we do not know how it affects our health, which worries many people. Scientists have done many laboratory experiments concerning the effects of EMF on organisms, but often with inconclusive results. This should not be surprising, because organisms are very complex systems. It would be simpler to begin by measuring the effects of EMF on water. After all, organisms, with over 60% water content, are like "bags of water".

Many scientists have indeed tried measuring water. They have found that, even with this "simple" substance, getting consistent results is a major challenge! They thought the biggest problem was contamination of water by atmospheric gases, particularly carbon dioxide, which alters water unpredictably. So experimenters tried outgassing water, or saturating it with a chemically less reactive gas such as nitrogen, and keeping the sample under isolated conditions during measurement. Most researchers also stirred water before or during measurement, to keep uniform sample quality. Researchers who took these and other precautions found that consistent data still evaded them. And scientists, consumers, and policy makers have continued to argue heatedly about whether EMF affect our health or not, without having clear data to support their views.

I am developing ways to get more consistent results in testing the effects of EMF on water. Among other quantities, I have measured pH, which indicates how acidic or basic water is. I tested whether pH of water changed after it was exposed to EMF for minutes to days, and also whether pH of exposed water differed from pH of non-exposed water.

In chemistry labs, pH readings are usually finished within minutes. Scientists usually put electrodes in a sample, wait a few minutes, take a reading, and the measurement is done.

From my previous experiments, I knew that pH electrodes take longer to stabilize in water than in other solutions, so I took measurements for a few hours. Again, my results varied widely from run to run, just as other researchers have reported. I repeated hundreds of experiments, only to get "inconclusive" results. For some reason, the pH of water fluctuates a lot, and unpredictably, during the first few hours of measurement. If there were an effect on pH from exposure to EMF, these fluctuations would mask it.

Then I extended the measurement time to days. To my surprise, much clearer differences showed up over this longer period. After the first few hours, after fluctuations disappeared, I could finally observe the effects of EMF on pH. Only by repeating these longer measurements, many times, could I demonstrate clearly that higher EMF exposure increases the long-term rate of pH change.

So when we study the effects of EMF on water, we may want to use a grandmother's clock rather than a stopwatch.