IARC report

On May 31, 2011, International Agency for Research on Cancer (IARC), an intergovernmental agency forming part of the World Health Organization of the United Nations, released a report (http://www.iarc.fr/en/media-centre/pr/2011/pdfs/pr208_E.pdf) announcing that radiofrequency electromagnetic fields has been classified as possibly carcinogenic to humans (Group 2B), associated with wireless phone use. This news has drawn public attention and caused confusion among general readers.

Mass communication media reported this release as a major societal issue, on par with the earlier one that mobile phone radio waves affect pacemakers. It is possible that the electronic devices such as pacemakers could cause malfunction when they are exposed by strong radio waves. Accordingly, one would understand the regulation that mobile phones should be kept at least 22cm away from pacemakers (this guideline was established for old devices which were already implanted, and 22cm is too far safe distance for recent mobile phones and pacemakers). However, the mechanism how specific substances like radio waves, cause or accelerate the growth of cancer is still unclear.

There have long been fears regarding the influence of radio waves on the human body. While the frequency is different from those used by mobile phones, there have been reports of a high incidence of leukemia for children living near high voltage power lines about twenty years ago in Northern Europe. However, the causal relationship between them has not been fully explained or reported.

Influence of radio waves on the human body

Why would radio waves have health effects?

Ever since Italian physician L. Galvani found and reported in the 17th century that muscle of frog's leg twitched by an electrical stimulation, we have learned that electrical pulses transmitted the biological signals through the neuron in the body. Because of this founding, we could make to create movement assistance devices.

The influence of this electromagnetic wave (those of 3 million megahertz or less are termed as radio waves in Japan) on the human body may be classified by its frequency. Electrical stimulation is a primary effect for low frequency radio waves. This is what we called as "electrocution" or "electrical shocks". This effect is now applied for electrical massage devices that relax tense muscles, and AED (automated external defibrillator) used for heart defibrillation.

The effect for the radio waves used in mobile phones is essentially thermal effect. Highly oscillated electrical fields can vibrate polarized water molecules in the body, and the friction energy produced by this vibration may raise the body's temperature. This is the principle of the operation used for microwave oven, a staple household cooking appliance. People might worry if the same effect happens when they use mobile phones. Needless to say, the field strength of the radio wave used for mobile phones is far different from that of microwave oven, whose field is concentrated in the closed metal box. Radio wave intensity in an open space is inversely proportional to the square of the distance from the transmission source. Therefore, the human head would be the most affected part by radio waves from a mobile phone in use.

Higher frequency electromagnetic waves include infrared waves, the visible spectrum, and ultraviolet waves. As known by the fact that ultraviolet light from sun causes sunburns and skin cancer, such electromagnetic radiation has a high level of quantum energy, which may destroy genes in cells, so that it is harmful to us.

Difficulty involved in epidemiological studies

About 20 years ago, the initial models of the mobile phones were bulky, heavy, and hard to use devices, which were owned only by those who have to equip, or latest technology mania. Technological advance has resulted in their miniaturization and weight reductions. Nowadays, some people own sometimes more than two mobile phones for different purposes. Mobile phones have evolved simple devices for voice calls, to more convenient and essential devices with multiple functions that satisfy our today's needs. Therefore, one cannot live without it, and will not power off not to miss any call or email.

It is very difficult to evaluate the effect of a substance such as radio wave, on the human body. For that purpose, one may apply epidemiological study methods, where the statistical process will be taken as how many people should be studied, and how many of them would exhibit what amount of effect in order for something to be deemed dangerous. This effect may vary between individual and psychological effects sometimes cause physical effects, too. Beneficial medicines can be harmful if taken in excess. Conversely, there are times when normally considered hazardous chemicals may be beneficial in small doses. Thalidomide was discontinued to use due to its negative effects on fetuses, but it is now being used again, to treat conditions such as leprosy and multiple myeloma. People enjoy going to radium hot springs, but nowadays nobody would go to visit a nuclear power plant.

The human body is adaptive to fit ourselves to the surrounding environment, and the technology using radio waves is constantly changing. We are living in an era where we can receive signals transmitted by probes on Mars, and telecommunication and signal processing technologies are continually advancing to communicate by even extremely weak signals. Accordingly, it seems likely, in the future, that guidelines to protect human body would be set on safer side.

One should take the present IARC report coolly, but keep attention to the future development. How many people quit from smoking or drinking, even after knowing the fact that tobacco is bad for the lungs, and alcohol is bad for the liver? Moderation in all things! Mobile phone addicts may consider reducing their phone usage in this opportunity, to find out an impact on their personal finances.

For researchers on electromagnetism, this issue is one of the un-avoidable important topics. There would be no shortage of research topics so far!