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13/11/2001 - Update on TETRA masts emissions from the NRPB

On 13th November the NRPB published a new version of their report Volume 12 No 2 Documents of the NRPB,
         "Possible Health Effects from Terrestrial Trunked Radio" that now has useful technical Appendices

At last, NRPB staff have now actually gone out and measured TETRA base station signals. They continue to insist that there is virtually no low frequency pulsing from them, and that the base station modes permitted within the TETRA Standard that would cause them to pulse are not implemented in the UK. The evidence they present seems to make a good case for no low frequency pulsing, but it isn't what I have found in practice with Dolphin TETRA base stations. It is a pity that they did not invite me to their measuring sessions so that we might have come to some mutual agreement on this difficult issue.

It may be the case for the BT Airwave base stations that are being built by Motorola, as I was told at a conference earlier this year by a senior BT Airwave Engineer that "we have told Motorola to set the software so that the mast doesn't pulse at low frequencies". I have yet to get to an active BTAirwave BS (they are all up in Lancashire and I am near Cambridge) and carry out the measurements that I have made on several Dolphin base-stations which did pulse in the way I described below - I was using a simple double zero-biased microwave schottky diodes pair to simply amplitude demodulate the carrier and I looked at it on an old analogue oscilloscope - and there was the clear pulsing. Fed to an audio amplifier a loud buzzing was heard. Not only were there the inter-time-slot pulses, but there was also some evidence of active down-link power control - i.e. the power transmitted in each time-slot varied seemingly depending on the power needed to reach the mobile handset. This causes a 17.6 Hz component. Active down-link power control is used on all modern mobile phone base stations - to save power and minimise co-channel interference problems. It isn't meant to be implemented in either BT Airwave or Dolphin TETRA base stations.

Some months ago I asked a senior BT Airwave manager for a copy of the detailed waveforms from the TETRA Standard Specification documents, as I couldn't afford the many hundreds of pounds that access to the full Standard costs. After a delay of several weeks he came back with "BT Airwave do not have a copy of the full TETRA Standard Specification documents", but he had asked Motorola and they had told him that their base stations do not amplitude pulse.Time will tell whether we find if this is correct, or not.

My main concern has always been for the people using the handsets, rather than people near to the masts. I still fear for the health of the Police 'guinea pigs' who will be health trialling this equipment. Remember that chronic adverse health effects usually show up only after many years. The brain-tumour delay with mobile phone use is beginning to look like at least 10 years normal use (5 years heavy use), and many slow growing solid tumours can take over 20 years from the time they are initiated to the time they are detected in the person.

The handsets, that are now starting to be used by our police officers, do pulse strongly, and I consider that there is some considerable risk of long-term adverse effects if they are regularly held close to users' heads. Avon & Somerset Police Federation Magazine, summer 2001, report that "although he doesn't think the handsets are likely to be dangerous", Professor Colin Blakemore suggests that "concerned officers might wear the transmitters on their belt and not use them close to their heads, and also provide a fine RF metal screening mesh incorporated into their uniform between the radio and their body". That sounds like sensible advice to me. It is not advice the the NRPB give, because they choose not to give ANY precautionary advice regarding non-ionising radiation risks below thermal heating levels.

I repeat the following paragraph from my earlier comments that their revised report still does not address:
Why is there not a discussion of non-linear transmembrane charge tunneling? Over the last 36 years there have been a considerable number of peer-reviewed published studies and theoretical papers that examine the extreme non-linear processes within the cell membrane. There are no papers listed by Freidmann Kaiser, Alwyn Scott, Clemens Eichwald, Keith McLauchlin, Ulrich Steiner or William Bialek. They have all made significant contributions to our understanding of nonlinear cell membrane electrodynamics.

This is my original response to the earlier version of this NRPB document........... »

On 31st July 2001 the NRPB published Volume 12 No 2 Documents of the NRPB,
         "Possible Health Effects from Terrestrial Trunked Radio"

Although we welcome their "Recommendations for Further Action" (para135, page 31), which we regard as positive, many of these tests should have been carried out before the Government spent £2.5bn on forcing this new system on UK Police forces. No human testing has been done with a system that has been planned in detail since the early 1990s. Why did people, like the NRPB's Dr A McKinlay, who represent the UK on the international standards committees not raise these issues years ago, so that the work could have been done before the Police were used as guinea pigs? This is an important question that needs a good answer.

I believe that this report is seriously flawed. It has obviously relied on the industry (TETRA MoU, Dolphin & BT Airwave) for much of its information about TETRA and they seem to have fed them misleading information.

For example, TETRA Masts do pulse. This is not "pulse modulation for transmitting the data", but sharp full-power synchronising pulses between 3 of the 4 time slots on each carrier with the 4th pulse being at zero power. This results in 3 pulses at 70.4 Hz and one "zero" pulse at 17.6 Hz, leading to significant amplitude modulation at 70.4 Hz and a lower, but audible when demodulated, signal at 17.6 Hz. This is quite detectable by people and animals due to the non-linear nature of cell membrane signaling that occurs in their bodies as part of life processes.

The repeated NRPB statements such as "It is notable that the signals from TETRA base stations are not pulsed, whereas those from mobile terminals and repeaters are." are just plain wrong. Apparently they relied on misleading written statements from the Operators and, despite their having adequate staff and equipment, did not go out and actually analyse the signals coming from an active TETRA base-station.

BT Airwave base-stations apparently emit stronger signals than Dolphin ones because BT Airwave keep all their carriers (often 3 or 4) turned on all of the time, whereas Dolphin use one and only activate extra carriers (each can carry 4 calls) when needed (at 5, 9 and 13 active calls). This will mean that BT Airwave signals will usually be between 2 and 4 times more powerful than Dolphin signals.

Why is there not a discussion of non-linear transmembrane charge tunneling? Over the last 36 years there have been a considerable number of peer-reviewed published studies and theoretical papers that examine the extreme non-linear processes within the cell membrane. There are no papers listed by Freidmann Kaiser, Alwyn Scott, Clemens Eichwald, Keith McLauchlin, Ulrich Steiner or William Bialek. They have all made significant contributions to our understanding of nonlinear cell membrane electrodynamics.

Their statement "Suggestions that pulsed RF fields could trigger epileptic fits or otherwise affect epilepsy sufferers appear to be unjustified" is not backed up with any test results using people who suffer from epilepsy. We are complex living beings and simplistic experiments on cells in a petrie dish do not accurately represent the reactions in a fully alive human being. There are anecdotal reports of people suffering epileptic fits near to masts. Some real research needs doing here using human volunteers who suffer from epilepsy.