14-08-2012, 11:15 AM
THE EFFECTS OF MICROWAVE RADIATION FROM TELECOMMUNICATION BASE STATIONS
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INTRODUCTION
Network Rail has plans to roll out a GSM communications system throughout their network. Upon the announcement that a GSM base station and transmitter was to be located at Yeoford station, the whole community had deep concerns about the visual impact on the environment and on the possible effects of the transmitter on the health of those living nearby. Several people have asked me to write a discussion of the latest research on health problems associated with base stations. This is of particular concern to Devon people because of the highly publicised cancer clusters around the Orange transmitter in Crediton and the shared transmitter in Pennsylvania, Exeter.
Mobile phones and GSM-mobile phones in particular are relatively new technologies, so there are few long term epidemiological studies that show statistically significant results, that is where results are unlikely to be due to chance. However, there is a growing body of research and anecdotal evidence that should not be ignored.
This is not an exhaustive study. It is a review of some of the published literature on the effects of microwaves, radio waves (RF) and electro-magnetic fields (EMF). Evidence is presented that emissions from microwave base stations do have effects on those living nearby. Studies on animals that demonstrate possible mechanisms for those effects are also discussed. Evidence is also presented that indicates similar effects from long term low level exposure and short term higher level exposure. Most of the papers are from peer reviewed journals, where the work is scrutinised by other academics before being accepted for publication.
THE GSM-R RAILWAY COMMUNICATIONS SYSTEM
The GSM-R system is similar to other GSM microwave systems. It is based on two way radio communication between a mobile handset in the train and the nearest base station. Each base station can serve a line length of up to 4km. in each direction, dependent upon the topography. Information received from Network Rail indicates that the main beam’s horizontal dispersion angle is between 25 and 65 degrees, dependent upon local topographic requirements. Commercial GSM base stations may have three transmitters to cover 360 degrees. Several GSM companies may share a particular mast, which increases the total microwave radiation emanating from that mast. There seems to be very little published literature on the effects of mast sharing. Network Rail have indicated that there are no plans to share masts with commercial GSM system providers, but there is evidence that the O2 company has applied for planning permission to share Network Rail masts and that Ultramast, (a subsidiary of Network Rail), is actively promoting the railway network as suitable for shared communications masts. Commercial pressure and current instructions to local councils make planning permission for mast sharing very possible.
The GSM-R system uses a carrier frequency close to 900MHz, with a frame repetition rate of 217Hz. The frames are transmitted in groups of 25, with the 26th frame missing, which results in additional low frequency wave pulsing of 8.34Hz, Hyland (2000). There is an additional pulsing at 2Hz in discontinuous transmission mode when there is no communication between transmitter and receiver. These frequencies correspond to signals within the human brain.
SAFETY LEVELS
In this country the relevant “safety” limit is laid down by the NRPB (National Radiological Protection Board) who have adopted the international (ICNIRP) maximum power standard of 0.4 mW/cm-sq (4W/m-sq) for frequencies in the region of those used by GSM technology. This standard, although international, is not universally adopted. In Australia the limit is 0.2 mW/cm-sq (2W/m-sq), Switzerland 0.0042mW/cm-sq (0.042W/m-sq) and Italy 0.01 mW/cm-sq (0.1W/m-sq) (and regionally enforced standards of 0.0025 mW/cm-sq (0.025W/m-sq)). The UK “safe” level of radiation is therefore 160 times higher (that is less stringent) than the regional Italian level. The NRPB guidelines are based on heating effects only (see below). The Salzburg Resolution (2000) recommended an outdoor exposure level of less than 0.1μW/cm-sq (0.001W/m-sq) in publicly accessible areas around a base station. This is 4000 times lower than the ICNIRP guideline value for 900MHz emissions. The Salzburg Resolution is the intensity below which no health effects have been published. The distance from a mast where this limit is exceeded depends upon the power, height and beam dispersion of the antenna.
The NRPB guidelines for exposure to low frequency electromagnetic fields (for example from high tension power lines) are similarly lax (1600 microtesla) compared with those in Italy (0.2 microtesla), Sweden (0.2 microtesla) and Australia (0.4 microtesla), (Henshaw (2002)).
THE EFFECTS OF MICROWAVE EMISSIONS ON LIVING ORGANISMS
Water based animals (humans, birds, mammals) absorb electromagnetic waves. In doing so minute electric currents can be generated within cells. This is analogous to the effect of radio waves on a crystal radio receiver, generating electrical currents in the aerial. It is these currents that are believed to be responsible for the effects described in the scientific papers discussed below.
The effects are divided into heating and non-heating effects.
Heating Effects
The heating effect is identical to that used in a microwave oven. The microwave energy is absorbed by the water content of food, which is why food gets hot and plates don’t. Heating effects become insignificant when distance from a microwave transmitter exceeds a few metres. This is why exclusion zones around mobile phone base stations are relatively small. However a bird perching on a phone transmitter would feel the heating effect very quickly. (It is of interest that the British Trust for Ornithology is investigating the effects of base station emissions on urban bird populations.) The main danger from heating effects is in using a mobile phone receiver. There have been many recent studies on these effects, eg. Frey 1998, who reported on potential causes of headaches associated with mobile phone use. Other studies have reported interrupted sleep, fatigue, warmth behind the ear and burning skin (Coghill (1998) cited by Trower (2001)). Mobile phone use is usually in short bursts of relatively high power emissions. This contrasts with exposure to base stations where emissions are of a much lower intensity but can be continuous.
Non-Heating Effects
Research on the effects of mobile communication technology is in its infancy, but the hazards of microwave, radio frequency (RF) and electromagnetic fields (EMF) emissions on living systems have been known since the Second World War. The use of microwaves as a weapon has been exploited by the Russians and Americans. Simon Best (2001), writing about microwave crowd control weapons: "after 20 years of rumours and speculation the Pentagon has finally confirmed that it has developed a device as part of its joint non-lethal weapons programme …". He continues, "in the UK many of the women protestors at Greenham Common in the 1980s experienced symptoms that they attributed to being zapped by microwave weapons from the US base". There was a scandal when US Embassy personnel and dependents in Moscow had been irradiated with up to 18 µW/cm2 of microwave radiation for up to 18 h/day as part of an espionage effort. There is evidence that two ambassadors developed leukaemia.
THE STEWART REPORT AND BEYOND
A group of independent experts led by Sir William Stewart has investigated possible health effects posed by mobile phone technology including base stations, on behalf of the Government. The group looked at recent research, took evidence from scientists, and listened to the views of the public at open meetings around the UK. Their report was published in May 2000.
Gaps in scientific knowledge led the Stewart Group to recommend a precautionary approach to the use of mobile phones and base stations until more research findings become available. They added that in some cases people's well-being may be adversely affected by insensitive siting of base stations.
Further research is now being set up to keep pace with developments in mobile phone technology. However, the largest experiment is the installation of GSM base stations around the country, using the general population as unwitting experimental subjects. It is clear from the above that evidence for the effects is emerging, but it may be many years before there is enough “proof” to overcome the commercial pressure for mobile communication. By that time it will be too late for many people.
HOW DOES THIS AFFECT LINE SIDE COMMUNITIES
Evidence is presented above that there are measurable effects from GSM base stations at distances of 300m. John E Moulder (Professor of Radiation Oncology, Medical College of Wisconsin) has stated on his web site that “the ground level power density does not drop with distance in any regular manner until you get at least several hundred meters away from a base station. Horizontal distance from a base station is less of a factor in ground level power density than antenna height, the antenna power and antenna pattern”. Certainly taller masts create lower emissions at ground level. At many proposed GSM-R base station locations, dwellings will be less than 500m from those base stations (the minimum exclusion zone recommended in Australia) within the 25-65 degree horizontal beam. If Network Rail continues with the plan to allow 3G phone operators to use their masts, the irradiated area becomes an annulus and more dwellings will be irradiated. We need to ensure that any emissions are below the threshold of reported biological effects. Microwaves radiate from transmitters over a wide area: from 3 to 9 miles. However, the radiation drops off quickly after 500-600m., and distance is the ally of safety. If taller masts allow the base stations to be sited further away from habitation, the reduced visual amenity within the landscape is far outweighed by the reduced risk to health.
CONCLUSIONS:
Over the last ten years many dozen peer reviewed studies have shown adverse biological or human health effects specifically from cell phone, base station and RF radiation. It is reasonable to group RF and microwave research because the effects are the similar. These research results to date clearly show that cell phones and cell phone radiation are a strong risk factor for all of the adverse health effects identified for electromagnetic radiation because they share the same biological mechanisms. Evidence presented above demonstrates that there is a risk from long term low level microwave exposure, as from base stations.
[attachment=31413]
INTRODUCTION
Network Rail has plans to roll out a GSM communications system throughout their network. Upon the announcement that a GSM base station and transmitter was to be located at Yeoford station, the whole community had deep concerns about the visual impact on the environment and on the possible effects of the transmitter on the health of those living nearby. Several people have asked me to write a discussion of the latest research on health problems associated with base stations. This is of particular concern to Devon people because of the highly publicised cancer clusters around the Orange transmitter in Crediton and the shared transmitter in Pennsylvania, Exeter.
Mobile phones and GSM-mobile phones in particular are relatively new technologies, so there are few long term epidemiological studies that show statistically significant results, that is where results are unlikely to be due to chance. However, there is a growing body of research and anecdotal evidence that should not be ignored.
This is not an exhaustive study. It is a review of some of the published literature on the effects of microwaves, radio waves (RF) and electro-magnetic fields (EMF). Evidence is presented that emissions from microwave base stations do have effects on those living nearby. Studies on animals that demonstrate possible mechanisms for those effects are also discussed. Evidence is also presented that indicates similar effects from long term low level exposure and short term higher level exposure. Most of the papers are from peer reviewed journals, where the work is scrutinised by other academics before being accepted for publication.
THE GSM-R RAILWAY COMMUNICATIONS SYSTEM
The GSM-R system is similar to other GSM microwave systems. It is based on two way radio communication between a mobile handset in the train and the nearest base station. Each base station can serve a line length of up to 4km. in each direction, dependent upon the topography. Information received from Network Rail indicates that the main beam’s horizontal dispersion angle is between 25 and 65 degrees, dependent upon local topographic requirements. Commercial GSM base stations may have three transmitters to cover 360 degrees. Several GSM companies may share a particular mast, which increases the total microwave radiation emanating from that mast. There seems to be very little published literature on the effects of mast sharing. Network Rail have indicated that there are no plans to share masts with commercial GSM system providers, but there is evidence that the O2 company has applied for planning permission to share Network Rail masts and that Ultramast, (a subsidiary of Network Rail), is actively promoting the railway network as suitable for shared communications masts. Commercial pressure and current instructions to local councils make planning permission for mast sharing very possible.
The GSM-R system uses a carrier frequency close to 900MHz, with a frame repetition rate of 217Hz. The frames are transmitted in groups of 25, with the 26th frame missing, which results in additional low frequency wave pulsing of 8.34Hz, Hyland (2000). There is an additional pulsing at 2Hz in discontinuous transmission mode when there is no communication between transmitter and receiver. These frequencies correspond to signals within the human brain.
SAFETY LEVELS
In this country the relevant “safety” limit is laid down by the NRPB (National Radiological Protection Board) who have adopted the international (ICNIRP) maximum power standard of 0.4 mW/cm-sq (4W/m-sq) for frequencies in the region of those used by GSM technology. This standard, although international, is not universally adopted. In Australia the limit is 0.2 mW/cm-sq (2W/m-sq), Switzerland 0.0042mW/cm-sq (0.042W/m-sq) and Italy 0.01 mW/cm-sq (0.1W/m-sq) (and regionally enforced standards of 0.0025 mW/cm-sq (0.025W/m-sq)). The UK “safe” level of radiation is therefore 160 times higher (that is less stringent) than the regional Italian level. The NRPB guidelines are based on heating effects only (see below). The Salzburg Resolution (2000) recommended an outdoor exposure level of less than 0.1μW/cm-sq (0.001W/m-sq) in publicly accessible areas around a base station. This is 4000 times lower than the ICNIRP guideline value for 900MHz emissions. The Salzburg Resolution is the intensity below which no health effects have been published. The distance from a mast where this limit is exceeded depends upon the power, height and beam dispersion of the antenna.
The NRPB guidelines for exposure to low frequency electromagnetic fields (for example from high tension power lines) are similarly lax (1600 microtesla) compared with those in Italy (0.2 microtesla), Sweden (0.2 microtesla) and Australia (0.4 microtesla), (Henshaw (2002)).
THE EFFECTS OF MICROWAVE EMISSIONS ON LIVING ORGANISMS
Water based animals (humans, birds, mammals) absorb electromagnetic waves. In doing so minute electric currents can be generated within cells. This is analogous to the effect of radio waves on a crystal radio receiver, generating electrical currents in the aerial. It is these currents that are believed to be responsible for the effects described in the scientific papers discussed below.
The effects are divided into heating and non-heating effects.
Heating Effects
The heating effect is identical to that used in a microwave oven. The microwave energy is absorbed by the water content of food, which is why food gets hot and plates don’t. Heating effects become insignificant when distance from a microwave transmitter exceeds a few metres. This is why exclusion zones around mobile phone base stations are relatively small. However a bird perching on a phone transmitter would feel the heating effect very quickly. (It is of interest that the British Trust for Ornithology is investigating the effects of base station emissions on urban bird populations.) The main danger from heating effects is in using a mobile phone receiver. There have been many recent studies on these effects, eg. Frey 1998, who reported on potential causes of headaches associated with mobile phone use. Other studies have reported interrupted sleep, fatigue, warmth behind the ear and burning skin (Coghill (1998) cited by Trower (2001)). Mobile phone use is usually in short bursts of relatively high power emissions. This contrasts with exposure to base stations where emissions are of a much lower intensity but can be continuous.
Non-Heating Effects
Research on the effects of mobile communication technology is in its infancy, but the hazards of microwave, radio frequency (RF) and electromagnetic fields (EMF) emissions on living systems have been known since the Second World War. The use of microwaves as a weapon has been exploited by the Russians and Americans. Simon Best (2001), writing about microwave crowd control weapons: "after 20 years of rumours and speculation the Pentagon has finally confirmed that it has developed a device as part of its joint non-lethal weapons programme …". He continues, "in the UK many of the women protestors at Greenham Common in the 1980s experienced symptoms that they attributed to being zapped by microwave weapons from the US base". There was a scandal when US Embassy personnel and dependents in Moscow had been irradiated with up to 18 µW/cm2 of microwave radiation for up to 18 h/day as part of an espionage effort. There is evidence that two ambassadors developed leukaemia.
THE STEWART REPORT AND BEYOND
A group of independent experts led by Sir William Stewart has investigated possible health effects posed by mobile phone technology including base stations, on behalf of the Government. The group looked at recent research, took evidence from scientists, and listened to the views of the public at open meetings around the UK. Their report was published in May 2000.
Gaps in scientific knowledge led the Stewart Group to recommend a precautionary approach to the use of mobile phones and base stations until more research findings become available. They added that in some cases people's well-being may be adversely affected by insensitive siting of base stations.
Further research is now being set up to keep pace with developments in mobile phone technology. However, the largest experiment is the installation of GSM base stations around the country, using the general population as unwitting experimental subjects. It is clear from the above that evidence for the effects is emerging, but it may be many years before there is enough “proof” to overcome the commercial pressure for mobile communication. By that time it will be too late for many people.
HOW DOES THIS AFFECT LINE SIDE COMMUNITIES
Evidence is presented above that there are measurable effects from GSM base stations at distances of 300m. John E Moulder (Professor of Radiation Oncology, Medical College of Wisconsin) has stated on his web site that “the ground level power density does not drop with distance in any regular manner until you get at least several hundred meters away from a base station. Horizontal distance from a base station is less of a factor in ground level power density than antenna height, the antenna power and antenna pattern”. Certainly taller masts create lower emissions at ground level. At many proposed GSM-R base station locations, dwellings will be less than 500m from those base stations (the minimum exclusion zone recommended in Australia) within the 25-65 degree horizontal beam. If Network Rail continues with the plan to allow 3G phone operators to use their masts, the irradiated area becomes an annulus and more dwellings will be irradiated. We need to ensure that any emissions are below the threshold of reported biological effects. Microwaves radiate from transmitters over a wide area: from 3 to 9 miles. However, the radiation drops off quickly after 500-600m., and distance is the ally of safety. If taller masts allow the base stations to be sited further away from habitation, the reduced visual amenity within the landscape is far outweighed by the reduced risk to health.
CONCLUSIONS:
Over the last ten years many dozen peer reviewed studies have shown adverse biological or human health effects specifically from cell phone, base station and RF radiation. It is reasonable to group RF and microwave research because the effects are the similar. These research results to date clearly show that cell phones and cell phone radiation are a strong risk factor for all of the adverse health effects identified for electromagnetic radiation because they share the same biological mechanisms. Evidence presented above demonstrates that there is a risk from long term low level microwave exposure, as from base stations.