|Social concern. Non-ionizing radiation, mobile communication and their effects on health.
This article focuses on human exposure to non- ionizing electromagnetic fields, including exposure to radiofrequency (RF) energies produced by communication equipment, mobile phones, base-station antennas and other sources. The authors relate some basic concepts concerning these fields and discuss how the human body responds to exposure to these types of radiation. They outline the international guidelines for limiting exposure to electromagnetic fields and providing protection against the adverse heath effects known so far. Symptoms and other non-confirmed effects derived from such exposure will also be discussed.
The world is constantly changing. Everyday there are new and more powerful technologies developed which are transforming our way of life, generally to improve it. This means a change in our environment, not always exempt from risks. Although with the scientific knowledge available today is not enough to reduce them down to zero, it is possible to control them if we use the right precautionary measures. Sometimes, the introduction of new technologies is critisised without having previously studied the risks that may arise as a consequence if its use. In the case of mobile communication we are not dealing with completly unknown technologies, in fact, radiocommunications were first used by the beginning of the 20th century with the first experiments of wireless telegraphy, carried out by Edward Branly in 1902. After that, the radio, the radar, the television and other devices came along, like the microwave. And none of these raised the alarm until the end of the century, concurring with the large-scale use of mobile communcation systems and devices.
«The better known natural source of electromagnetic energy is the Sun, without which life on Earth would not be possible»
«In exposure to radiofrequency source emissions which are not close to the human body , like mobile telecom BS antennas, there have been reports of symptoms like fatigue, headaches or concentration problems»
|Electromagnetic fields and non-ionising radiations
The better known natural source of electromagnetic energy is the Sun, without which life on Earth would not be possible. Let’s simply think about the need for light and heat for the realization of the chlorophyll function of plants. The Sun emits radiations throughout the whole frequency electromagnetic spectrum, from ionising radiations (X-Ray, Gamma rays and cosmic radiations), through optic radiations, non-ionising, and also radio communication frequencies, to low level frequency radiations like the ones produced by high-voltage lines and household appliances. In the same way there are radiations coming from the stars and other celestial bodies in our planet’s natural environment.
In the same way as we live surounded by natural electromagnetic fields, there are also electromagnetic fields produced by humans. Thus,we have as examples of non-ionising electromagnetic radiations those of low frequency appliances like washing machines or hair dryers and those of a high frequency like microwaves, mobile phones, radio and television BS antennas, WiFi devices, etc.
|Distribution of the Specific Absortion Rate (SAR), averaged to 1 gram, for the adults’ model (left) and the ten year old children’s (right). In this picture we can see the differences between the SAR of two heads exposed to the same level of mobile phone radiation power, with a frequency of 900 MHz and a radiated power of 250 MW, with a distance of 1.5 metres of the head from the antenna.
«The concern for mobile telecom antennas exposure is still very important, despite the fact that the measured levels are hundreds of times below the safety limits »
|Effects and symptomS
Regarding the exposure to radiofrequency source emissions which are not close to the human body , like mobile telecom BS antennas, there have been reports of symptoms of hypersensibility to microwaves. These symptoms are, for example, fatigue, headaches, concentration problems, etc. These symptoms, though real, have not been proved to be related to the exposure to radiofrequencies. It has not been shown either that there is a direct relationship between them and a specific source of emission, since we lack studies on the relative contribution of the different sources of exposure (BS antennas, mobile phones, etc.) on each individual. Other effects on the nervous and reproductive systems, as well as cancer induction, have not been proven untl now. Regarding the use of mobile phones, in which exposure occurs close to the individual’s head, according to the latest studies, brain tumor production in adults is ruled out. These conclusions have been recently published by the Scientif Committe on Emerging and Newly Identified Health Risks.
Lately, a new social concern has emerged due to the exposure to some other wireless radiofrequency new technologies, like WiFi devices, which are being installed in schools and other areas of Internet collective use. It is worth pointing out that the emission power of these devices is lower than that of mobile phones. Moreover, since exposure happens in a greater distance from the source, electromagnetic fields are of lower intensity and, therefore, the level of exposure is lower than in the case of mobile phone use.
In Spain, the concern for mobile telecom antennas exposure is still very important, despite the fact that the measured levels, published by the Spanish Ministry of Industry, are hundreds of times below the safety limits established by the Spanish and European regulatory frameworks. Citizens have a right to be informed about any risk related to exposure to mobile telecom radiofrequencies or any other kind of electromagnetic field produced by the current and future technologies. It is necessary for each one of us to contribute to improve social acceptance of the newest technologies, which have as a main goal to improve our quality of life, taking into account that zero risk does not exist.
Excerpts from the original article published in Mètode 57, Spring 2008.
Mercedes Martínez Búrdalo, Agustín Martín Múñoz and Raimundo Villar Gómez work at the Department of Electromagnetic Radiation. Institute of Applied Physics, CSIC. Madrid.
© Mètode 2011 - 57. Radiations - Issue 57. Spring 2008