|
|
|
Electromagnetic radiations and your health
Effects of EM fields on Health (III) The human body is "under tension" due to the chemical reactions that occur through our metabolical activity. These currents are even present in the absence of external electric fields : in the brain of course or during the process of digestion. Even the heart is electrically active (remember the electrocardiogram). Low-frequency electric fields affect the human body just as they influence any other electrically charged material. When tissues become conductive, they influence the distribution of electric charges at their surface; in other words they cause current to flow through the body to the ground. Low-frequency magnetic fields induce circulating currents within the human body. The strength of these currents depends on the intensity of the outside magnetic field. If sufficiently large, these currents could cause stimulation of nerves and muscles or affect other biological processes. Both electric and magnetic fields induce voltages and currents in the body but even directly beneath a high voltage transmission line, the induced currents are very small compared to thresholds for producing shock and other electrical effects. Heating is the main biological effect of the EM fields at radiofrequencies (RF). In microwave ovens this fact is employed to warm up food. The levels of radiofrequency fields to which people are normally exposed are very much lower than those needed to produce significant heating. The first signs of electromagnetic radiation effects on the health arose after the Second world war to US Navy workers. American scientists were alerted by a syndrome resembling to a mild radiation poisoning. They find in surveying radar-exposed workers a high incidence of internal bleeding, 2 leukemia cases in 600 radar operators, 2 brain tumor cases in a 5-man microwave research team, and many complaints of headache. The report was sent to the Pentagone in 1953. Electrical engineers from the Navy then tried to identify a safe level of microwave exposure for servicemen. Biophysicist Herman Schwan played a major role in establishing at 10 mW/cm2 the thermally safe microwave exposure limit. Today, we have seen that FCC admits an upper limit of 5 mW/cm2 in controlled environments while european recommendations are 8 times higher ! The heating effect of radiowaves forms the underlying basis for current guidelines. Scientists are also investigating the possibility that effects below the threshold level for body heating occur as a result of long-term exposure. To date, no adverse health effects from low level, long-term exposure to radiofrequency or power frequency fields have been confirmed, but scientists are actively continuing to research this area. Biological effects are measurable responses to a stimulus or to a change in the environment. These changes are not necessarily harmful to your health. For example, listening to music, reading a book, eating an apple or playing tennis will produce a range of biological effects. Nevertheless, none of these activities is expected to cause negative health effects. The body has sophisticated mechanisms to adjust to the many and varied influences we encounter in our environment. An organism that doesn't react face to its environment is a death organism. It cannot survive because it is unable to adapt. Ongoing change forms a normal part of our lives and of our evolution. But, of course, the body does not possess adequate compensation mechanisms for all biological effects. Changes that are irreversible and stress the system for long periods of time may constitute a health hazard. The best example is the effect of radioactivity or of a too high temperature. To
read : Centrale
nucléaire et cancer: un lien de cause à effet ? Statistical studies of cancer risks close to nuclear power stations and power lines
An adverse health effect causes detectable impairment of the health of the exposed individual or related. Such an effect can be for example the leukamia or cancer of cells. A biological effect, on the other hand, may or may not result in an adverse health effect. It is not disputed that electromagnetic fields above certain levels can trigger biological effects. Experiments with healthy volunteers indicate that short-term exposure at the levels present in the environment or in the home do not cause any apparent detrimental effects. Exposures to higher levels that might be harmful are restricted by national and international guidelines. The current debate is centred on whether long-term low level exposure can evoke biological responses and influence people's well being. The subject of all debates is of course the famous HV power lines. Power lines and ELF Due to their extremely high energy, HV power lines are of course a special case. Directly beneath power lines the fields are much stronger and epidemiological studies confirmed that they are source of cancers if the exposure is very long. Electric field levels underneath power lines and up to 25 m away can be as high as 10 kV/m, and are thus potentially at risk after a long exposure. But how long ? Probably a life... Thus the risk is not greater than the life itself (you can easier die in a car accident, a gas explosion, etc) ! However, the fields, both electric and magnetic, drop off from the lines 4 times in intensity each time the distance double (law in 1/r2). At 50 m to 100 m distance the fields are usually at levels that are found in areas away from high voltage power lines. However, IRPA has noticed the development of leukamia when people are exposed to electromagnetic fields equivalent to a distance up to 75 m from a 400 kV power line.
According to WHO, pooled analyses of epidemiological studies conducted in 2002-2003 provide insight into the epidemiological evidence that played a pivotal role in the IARC evaluation. These studies suggest that, in a population exposed to average magnetic fields in excess of 0.3 to 0.4 μT, twice as many children might develop leukamia compared to a population with lower exposures. In spite of the large number data base, some uncertainty remains as to whether magnetic field exposure or some other factor(s) might have accounted for the increased leukamia incidence. We must know that IARC has listed approximatively 900 carcinogenic agents !... Nobody can handle all possible permutations and side effects induced by so many possible reactions, hence the incertainty often haging over this kind of study. The uncertainty is still larger when speaking of potential risk for the foetus to pregnant women staying at home near HV power lines or deseases like cataract that some workers would have contracted after worked on HV pylons. The case the most studied is the childhood leukamia. It is a rare disease with 4 out of 100,000 children between the age of 0 to 14 diagnosed every year. Also average magnetic field exposures above 0.3 or 0.4 μT in residences are rare. It can be estimated from the epidemiological study results that less than 1% of populations using 220-240 volt power supplies are exposed to these levels, although this may be higher in countries using 110-120 volt supplies. In another hand, electrical companies have noticed strange behaviours in some electrical devices used in farms located just beneath HV pylons : flickening of neon lamps, temporary interruption of motors, etc. These effects are concrete and quantifiable and add to the epidemiological risk to confirm that these HV power lines induce unattended effected, and more than probably biological effects at short distance (< 75 m). As for knowing if we can eat or not apples or strawberries that ripped under such EM fields or eat meat of animals having lived under these radiations, no one can answer because effects are little studied as it and hard to quantify. But if a health risk should occur, it seems in all cases by far lower that the one of transgenic foods as we haven't noticed yet biological effects in the nature of fruits or the metabolism of concerned animals. In all cases, nature has always created new species or varities of fruits or animals without that their consumption is harmful to human being. 5G technology As with previous cellular technologies (2G, 3G, 4G), 5G networks rely on signals carried by radio waves (RF) transmitted between an antenna and a mobile device. 5G uses higher frequency waves than previous mobile networks (3.5 GHz plus 700 MHz and 26 GHz against for the 4G, 700, 800 and 1800 MHz bands). The increase in frequency allows more devices to access the Internet simultaneously and at speeds on average 10 times faster than the previous technology (at least 1 Gbit/s in reception/download and twice as slow in transmission/upload, cf. this chart and the tool SpeedTest). These waves travel shorter distances through urban spaces, so 5G networks either require more transmitting antennas than previous technologies, positioned closer to the ground, or fewer antennas but more powerful than previous technologies. What are the concerns? In recent years, the media have reported the concerns of the public and "anti-5G" associations who see it as an additional and much more powerful source of unwanted electromagnetic radiation and a way for smartphone manufacturers to gain money. money as billions of users will want to replace their cellphones with a model that supports 5G. But is the problem really there? As we have explained, it is a fact that the electromagnetic radiation used by all mobile phone technologies raises the question of health risks, especially the development of certain types of cancer or electrosensitization. In 2014, WHO declared that "no adverse health effects have been established as being caused by mobile phone use". However, the International Agency for Research on Cancer (IARC) which is a research agency of the WHO has classified all radioelectric radiation (of which mobile signals are part) as "probably carcinogenic to humans" (group 2A) . They were placed in this category because "there is some inconclusive evidence that exposure can cause cancer in humans" (cf. IARC/WHO). But remember that eating pickled vegetables and using talcum powder are classified in the same category. Alcoholic beverages and processed meat (cf. WHO) are even placed in a higher category because the evidence is stronger.
A 2018 toxicology report released by the US Department of Health, and highlighted by those who have expressed safety concerns, found that male rats exposed to high doses of radiofrequency developed a type of cancerous tumor in the heart. For this study, whole bodies of rats were exposed to cell phone radiation for nine hours per day every day for two years, starting before birth. No cancer link was found in the female rats or mice studied. Rats exposed to radiation were also found to live longer than those in the control group (cf. Science-Based Medicine). A scientist, co-author of the study, said that "the exposures used in the studies cannot be directly compared to the exposure humans experience when using a cell phone", even for heavy users. In Great Britain, Dr Frank De Vocht advises the UK government on cell phone safety. He said that "although some of the research suggests a statistical possibility of increased cancer risks for heavy users, the evidence to date for a causal relation is not sufficiently convincing to suggest the need for precautionary action". However, a group of scientists and doctors wrote to the European Commission to call for the end of the deployment of 5G on the grounds, in particular, that its frequency spectrum was at the limit of ionizing radiation and that we had no hindsight to assess its possible harmfulness to health. Obviously, Europe was not convinced because in its State of the Union address held on September 18, 2020, "the Commission calls on the Member States to strengthen the high-speed connectivity of networks and to define a common approach for the deployment of 5G". For its part, on July 24, 2020, the Council of Europe called on member states "to establish a common strategy based on an objective assessment of the risks identified and on proportionate mitigation measures to face the risks in terms of security related to the deployment of 5G". Remember that the RF band used for mobile telephone networks is non-ionizing. This means that the waves do not have enough energy to break apart DNA and cause cellular damage. These radio waves even carry much less energy than the sunlight we are exposed to every day. On the other hand, higher up in the electromagnetic spectrum, well beyond the frequencies used by cell phones, there are clear health risks associated with extended exposure. In summary, if during intensive use there is evidence of effects in some animals, for the uses for which they are intended, there is no reliable evidence that cell phones or Wi-Fi networks represent a risk to human health. Radiation from 5G antennas 5G technology requires many new base stations - cell masts transmit and receive mobile phone signals. In the 3400 to 3800 MHz band, the waves emitted are twice as intense as the sum of the relay antennas of 2G, 3G and 4G technologies combined. In addition, people living near relay antennas will be exposed to power density levels at least 3 times higher than today. It is for this reason that in Belgium for example, where the legislation in this area is one of the most severe in the world, and the thresholds lowest, the exposure threshold (in W/m²) has been raised and multiplied by 6 in anticipation of the deployment of 5G! As for the heat radiated by microwaves (when they pass through objects), at the levels used for 5G (and previous mobile technologies), the effects of heat do not are not harmful. According to Rodney Croft, ICNIRP advisor, "The maximum radio frequency level that someone in the community could be exposed to from 5G (or any other signals in general community areas) is so small that no temperature rise has been observed to date". Exposure limits Directives from various European governments (British, German, Belgian, etc.) state that while a slight increase in overall exposure to radio waves is possible when 5G is added to the existing network, the overall exposure should remain low. The frequency range of 5G signals is in the non-ionizing band of the electromagnetic spectrum and well below those considered harmful by the ICNIRP. According to Croft, "The exposure that 5G will produce has been considered in great depth by ICNIRP, with the restrictions set well below the lowest level of 5G-related radio frequency that has been shown to cause harm". For its part, the WHO says that exposures to electromagnetic frequencies below the limits recommended in the ICNIRP guidelines do not appear to have any known consequence on health. Comments An independent observer might note that ICNIRP reports are in part written by scientists paid for by industry. We can deduce that the opinions of the ICNIRP are not objective and go in the direction of the manufacturers who are impatiently awaiting the deployment of 5G. Since ICNIRP works for WHO, therefore the opinion of WHO is biased. The organization does not defend the health and interests of the population because it should have reminded everyone of the precautionary principle, and therefore not support the deployment of 5G without conditions. In general, the experts' opinions are in line with the ITU (International Telecommunications Union) which concluded in 2017 about 5G: "As a new system, it will apply many new features that will increase its efficiency and its flexibility. Reducing the impact on electromagnetic fields is one of the most important issues considered in the development of the 5G system. It can be assumed that the 5G system will not increase the level of exposure in the 'human environment". We also conclude that as for BPL, the fight of "anti-5G" is lost in advance. Remember that despite the reluctance, the deployment of 5G has already started in Europe. It is deployed in the United Kingdom, in Germany, in Holland, in Switzerland, in the north of Belgium (Brussels and Wallonia refuse to do so for the moment), it will be deployed in Luxembourg in October 2020 and in France in 2021 (cf. the Interactive Ookla 5G Map). These are the data in the file. A guideline Now that we gathered all elements and know the potential risks, what can we conclude from all those data ? As we told previously, all data gathered up to date give not black or white results in this matter.
In this context, an important remark to make is that any guideline will never give a precise delineation between safety and hazard. There is no one level above which exposures become hazardous to health; instead, the potential risk to human health gradually increases with higher exposure levels. Guidelines indicate that, below a given threshold, electromagnetic field exposure is safe according to scientific knowledge. However, it does not automatically follow that, above the given limit, exposure is harmful, hence the "laisser-aller" in the matter by the authorities. Nevertheless, the public does not react like authorities ! On one hand, we know from sad experiences, that some governments and many industrials, private or public, have sometime hidden accidents in which population was contaminated (Bophal, Mururoa, NTS, Chernobyl, etc). We have thus correctly to interprete these studies and check the behaviour of our leaders as the one of industrials sometimes criminals. On the other hand, the public has a tendency to fear what he doesn't know. Concerning EM fields, being invisible, odourless and silent, the non informed public has a tendancy to credit them with all harms of the earth despite transparency and results mostly negative emerging from scientific studies. To be able to set limits on exposure, scientific studies need to identify the threshold level at which first health effects become apparent. As humans cannot be used for experiments excepted by accident (all cases of leukamia enter in this category), guidelines critically rely on animal studies. Subtle behavioural changes in animals at low levels often precede more drastic changes in health at higher levels. Abnormal behaviour is a very sensitive indicator of a biological response and has been selected as the lowest observable adverse health effect. Guidelines recommend the prevention of electromagnetic field exposure levels, at which behavioural changes become noticeable. This sanitary safety threshold is not equivalent to the limit recommended by the institutions or legally nor to the Specific Absorption Rate (SAR index). For security reasons, the ICNIRP, an international commission working with WHO, applies a reduction factor of 10 in exposed work areas and a factor of 50 in public places (private or uncontrolled).
Table 5 - Source : ICNIRP, "EMF guidelines", Health Physics 74, 494-522 (1998) and ITU (2017) In general, it is agreed that maximum exposure to magnetic fields (power density) should not exceed 2 W/m2 or 2 W/kg for smartphones, which is also a recommendation from ICNIRP. In practice, the threshold of domestic appliances is often 10 to 20 times lower and therefore in theory without any effect on health. But people hypersensitive to electromagnetic fields will tell you that this level is still too high and these people have no choice but to isolate themselves in places without antennas or any device emitting a magnetic field. In the RF spectrum (10 MHz - 300 GHz) the maximum energy levels to which we may be exposed in the environment or at home are at least 50 times lower than the threshold at which the first behavioural changes in animals become apparent. It's good news ! May be less for your little rat or mouse taken out of a laboratory. That said, knowing that the risk 0 does not exist, there is a residual risk of exposure to electromagnetic fields and especially that of household devices (GSM, Wi-Fi, etc.) but their long-term effects are not yet known.
Table 6 - Source : WHO Regional Office for Europe One thing is sure. Animal experiments have shown that intense electromagnetic fields are harmful to health. In humans, as some hypersensitive people may testify, the magnetic fields can trigger an almost allergic reaction from one day to the next without the threshold of intolerance being defined since most people are apparently insensitive to it. Regarding mobile phones and other connected tablets, as a precaution, it is advisable not to have his mobile phone by ear several hours a day and every day of the week for years. It is best to use a hands-free kit and leave your mobile phone at a distance from yourself to avoid being in the field of the most powerful emissions (specially when it rings or search for a network). Same problem for tablets, Wi-Fi-routers and other devices emitting electromagnetic waves. Avoid calling when the reception is bad. If this is the case, move to a better covered area or call back from your computer (Skype) or from a landline. Finally, it is probably in the car and public transports that the electromagnetic fields are the most harmful because they must be strong enough to get through the metal body, therefore the reception is often bad in cars. Equations and simulations Most of the situations in which the power density would be high enough to be of concern are in the near field—an area roughly bounded by several wavelengths of the antenna. In the near field, ground interactions and other variables produce power densities that cannot be determined by simple arithmetic. To check : Amateur Radio RF Safety Calculator RF Field Strength Meter (in kit)
Computer antenna-modeling programs such as MININEC or other codes derived from NEC (See simulations software on this site) And yet, these too have limitations. Ground interactions must be considered in estimating near-field power densities. Also, computer modeling is not sophisticated enough to predict "hot spots" in the near field— places where the field intensity may be far higher than would be expected. Intensely elevated but localized fields often can be detected by professional measuring instruments. These "hot spots" are often found near wiring in the shack and metal objects such as antenna masts or equipment cabinets. But even with the best instrumentation, these measurements may also be misleading in the near field. One need not make precise measurements or model the exact antenna system, however, to develop some idea of the relative fields around an antenna. Computer modeling using close approximations of the geometry and power input of the antenna will generally suffice. Those who are familiar with MININEC can estimate their power densities by computer modeling, and those who have access to professional power-density meters can make useful measurements. While our primary concern is ordinarily the intensity of the signal radiated by an antenna, we should also remember that there are other potential energy sources to be considered. You can also be exposed to RF radiation directly from a power amplifier if it is operated without proper shielding. Transmission lines may also radiate a significant amount of energy under some conditions. By way of conclusion The WHO has defined seven main health effects of EM field : - A wide range of environmental influences causes biological effects. "Biological effect" does not mean "health hazard". Special research is needed to identify and measure health hazards. - At low frequencies, external electric and magnetic fields induce small circulating currents within the body. In virtually all ordinary environments, the levels of induced currents inside the body are too small to produce obvious effects. - The main effect of radiofrequency electromagnetic fields is heating of body tissues. - There is no doubt that short-term exposure to very high levels of electromagnetic fields can be harmful to health. Current public concern focuses on possible long-term health effects caused by exposure to electromagnetic fields at levels below those required to trigger acute biological responses. - Many institutions are today working on projects providing scientifically sound and objective answers to public concerns about possible hazards of low level electromagnetic fields. - Despite extensive research, to date there is no evidence to conclude that exposure to low level electromagnetic fields is harmful to human health. - The focus of international research is the investigation of possible links between cancer and electromagnetic fields, at power line and radiofrequencies. Without more indication, for your own health stay over 100 meters from HV power lines. Further RF exposure suggestions Potential exposure situations should be taken seriously. Based on the FCC/EPA measurements and other data, the "RF awareness" guidelines of Table 3 were developed by the ARRL RF Safety Committee. A longer version of these guidelines, along with a complete list of references, appeared in a QST article by Ivan Shulman, MD, WC2S (see Bibliography below). In addition, QST carries information regarding the latest developments for RF safety precautions and regulations at the local and federal levels. If you are looking for an electromagnetic signal meter, two models are recommended, CellSensor or EM eye. Their price is about $100. Many other brands, world-wide, provide similar tools. Regarding scientific publications on the impact of magnetic fields on health and especially GSM antennas, globally the opinions are divided, what explains that the subject has been debated for several decades with on the one hand researchers who have interests with industry of that sector and do not see any negative impact on the use of magnetic fields and on the other the few objective researchers and and hypersensitive persons who, on the contrary, have demonstrated the risks for health induced by electromagnetic fields that are too close or too intense.
For more information Instruments - RF Field Strength Meter (kit) - PCE Instruments (including EM field detector PCE EMF 823) Publications and standards - Lennart Hardell's publications - Alexander Lerchl's publications - Olle Johansson's publications - Cell Phone, FDA - IARC - RF Exposure and You, ARRL ($23) - Using a cell phone for one hour increases cancer risk by 500% study shows, Natural News, 2016 - Power-Line Noise Mitigation Handbook for Naval and Other Receiving Sites, ARRL/TIS - Power Lines and Cancer: Nothing to Fear, John W. Farley, 2003 - Effects of RF radiation, RF Safe - Overview of Effects and Protection of Non-Ionizing Radiation, Maila Hietanen/FIOH, 2000 - ITS Publications, ITS - Spread Spectrum Scene (liste de publications sur les champs EM) - International Commission on Non-Ionizing Radiation Protection Guidelines for limiting exposure to time varying electric, magnetic and electromagnetic fields (up to 300 GHz)", Health Physics, 74(4), p494-522, (1998). - IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz", ref. IEEE Standard C95.3-2002, 2002 (data 1991). °This document is reprinted from the "1997 ARRL Handbook for Radio Amateurs", Copyright ©1996 American Radio Relay League, Inc. Additional text about risks for health, temperature of semiconductors, concerns about GSM, Wi-Fi, ELF, references, tables and updates are from the author, LX4SKY. This material may be reproduced for noncommercial use, provided that credit is given. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
