I don't blame anyone for not wanting one near their homes or school. I'd fight like hell to stop them.
The problem is that we don't know what are the long-term, effects of low-incidence exposures of these kinds, especially on susceptible populations -- and growing children are obviously a concern.
For the time being here is a list of studies about television and transmission towers which is relevant to the issue. These notes come from various sources.
There are now a number of reports of raised levels of leukemia and cancer near broadcasting and microwave towers :
Dolk - Sutton Colefields and others (1997)
Hocking - Sydney TV (1996)
Honolulu - broadcasting (1987); Navy communications (1987)
Scotland - Navy communications (1992)
Portland, Oregon (1982)
The 1996 University of Bern Schwarzenberg study on short wave masts is a possible example of what may be a problem for people living close to a transmission Mast,
The 1998 "Loscher & Kas" study into the Extraordinary Behaviour Disorders in Cows in proximity to transmiting stations ought to be sounding warning bells throughout this enormous industry.
A study carried out in the mid 1990s by the University of Beme It was found that the emissions from that mast did have an effect on the people in the vicinity. This was discovered because during the period of the study there was a significant drop in the symptoms in many people over a three day period within that prolonged study. It was then discovered, which was not known at the time, that the transmitter had failed for those three days and there were no short-wave transmissions. The Swiss government has now closed the Mast down.
Incidentally, the Swiss health and environmental officials have proposed strict rules for public exposures from new sources of radio frequency and microwave radiation. If the ordinance is adopted, which appears likely, Switzerland will have the most stringent exposure levels in the world - based on the precautionary principle - guideline levels much lower than those recommended by the NRPB.
This is possibly some other evidence of low-level incidence problems.
Miscarriages among Female Physical Therapists who report using radio-and microwave-frequency electromagnetic radiation. American Journal of Epidemiology, Vol 138 (10), Nov 15, 1993.
Dr Lebrecht Von Klitzing Low-frequency pulsed electromagnetic fields influence EEG of man. Physical Medica XI (2), 1995.
Dr. John Goldsmith, Epidemiological Evidence of Radiofrequency Radiation (Microwave) Effects on Health in Military, Broadcasting, and Occupational Studies. International Journal of Environmental Health, 1 pp 47-57, 1995.
Dr Bruce Hocking Cancer incidence and mortality and proximity to TV towers, Medical Journal of Australia, Vol 165, 2/16, 1996
Dr. Neil Cherry, Scientific Evidence of the Risk of Adverse Health Effects from Chronic Exposure to Low Level Electromagnetic Radiation, address March 4, 1997.
And some notes about exposure levels:
Radiated isotropically with no directional gain in the antennas you would normally expect levels of 5 to 10 uW/cm2 at 1kilometre from the mast, and 1 uW/cm2 at about 3 km.
Antennas on masts usually have directional gain.
It is doubtful that any radio or TV masts in the UK exceeds about 1 MW ERP (Effective Radiating Power). Most are less than that.
The main transmitters are 100 to 250 kW per frequency. Mast height will obviously drop the received signals on the ground even more. The powers received from more than one transmitter is added as the root sum of squares. i.e. 5 x 0.25 MW = Sqrt(5x0.25x.25) = 0.56 MW.
All the main tranmitter masts measured in the UK have had no high ground within at
least about 20 km.
Some safety aspects of radiofrequency radiation (8. February, 1996 )
pW=picoWatt (10 -12 W)
nW=nanoWatt (10 -9 W)
ĶW=microWatt (10 -6 W)
mW=milliWatt (10 -3 W)
Cellular phone Frequency 800-880 MHz ( Microwave )
Having received several inquiries asking about alternatives to exposure levels currently in use I want to provide the following: The calculations are based on the electrophonic effect, which I have recommended as an adequate comparison. Those calculations lead to an ambient level of about 100 pW/cm≤ = 0.1 nW/cm≤ as the equivalent value at which ambient noise is perceived as "quiet" (8 db). Subliminal noise levels are here not considered.
If we accept this level as maximum for permanent exposure most populated areas in Canada are heavily overexposed already! Unless convincing data are provided one can argue that the lowest value that can be derived from existing data should prevail. Safety Code 6 allows for much higher levels which could be rejected for being inadequate and based on insufficient procedures.
The above given level still allows for the operation of systems from a technical point of view. Considering that 0.6 W = 600mW are sufficient to reach this towers with a cellular phone the opposite direction should be able to communicate with the same power level. This is technically achievable !
Safe distance calculation based on this level of 100 pW/cm≤
here are some examples:
According to my local office of Industry Canada the normal output is on average 70W but up to 10 channels are allowed so the maximum output at such towers can be 700W and the safe distance would then be 7.5 km (4.6 miles).If 400 m (1330 ft) is the distance from a 300 ft (100m ) tower the maximum power at this site should not exceed 2 W ! With 10 channels on one site operated with 3W each, the same as car phones and bag phones, the total output would be 30 W. The safe distance for such a site would be 1600m (~ 1 mile ). In many cases these distances are not maintained and the allowable power exceeds the above given values excessively. Using this value would translate to a safe distance from a tower with 100 W radiation power of about 2.8 km (1.75 miles).
The calcuations assume a permanent radio output, as it is the case with most cellular communication towers .
They do not take in consideration other sources of radiation like TV, or Radio transmitters. If there are more transmitters in the vicinity the radiation has to be added up, consequently reducing the power at the new site, or moving it to a safe distance that the combined levels are below this value.
It is to be expected that this level will be dismissed as unrealisticly low, but even if higher levels would be proven guaranteed safe one should demand that only the lowest possible level is permitted that still allows the operation of the system (energy conservation). There may be some technical adjustments necessary, but that should be done! The operation of the system is generally not jeopardized with lower power.
This can not be set aside only for the reason that Safety Code 6 allows higher levels. One could even take the position that there is no specific reference in the code at all, so zero tolerance is valid until the code refers to accumulative permanent exposure. The code is still only refering to occupational exposure. Considering that the exposure of the public is involuntary and permanent, asking for power limits to such transmitters seems quite reasonable, and it is technically possible and justifiable.
However, the currently permitted levels of radiation are more than hundred thousand times higher ! With the powerful interest of the industruies in this field unfortunately no change is to be expected.
|Update September 1997 :
The new review of Safety Code 6 in its preliminary form has again no accumulative limits, it will state and allow permanent public exposure levels (accumulative over 24 hours) nearly equivalent to those for worktime occupational exposure ( 8 hours). Professionals in this field are well payed and covered by disability insurance - the unaware public is not "protected". The radio/micro wave pollution continues to increase steadily.
Update February 1998:
The World Health Organisation WHO has called for a symposium on the health hazards of wireless communications citing such possible dangers as tumors and cancers caused by the use of modern telecommunication devices. Hopefully this will lead to new research and better standards and not only to a whitewash on behalf of the industry.