The 40-meter high truncated pyramid that forms the PAR has 3 faces each containing an array of 2,560 aerials, transmitting at 420-450 MHz with a total mean power output of 2.5 Megawatts a range of around 3000 miles and is able to operate over a full 360^o. The main radar beam is directed to be at least 3^o above the horizontal, however side lobes can reach the ground.

At the time of the PAR upgrade to the system (previously it consisted of three mechanically steerable dishes housed in radomes) in 1993, an ElectroMagnetic Radiation (EMR) Survey of the area surrounding Fylingdales was commissioned by the Nuclear Free Local Authorities [1] . The survey was an extension of an earlier report produced in the summer of 1991 and used 23 measurement sites, including moorland paths and tracks, roadside locations and habitations. The survey found maximum field values of about 10Vm^-1 which were in fact quite close to the currently accepted international standards developed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels of 28-29Vm^-1 for the Fylingdales frequency range [2] . The MoD says that “UK safety thresholds are based on NRPB guidelines and not those of ICNIRP” [3] . However, the European Council Recommendation 1999/519/EC requires member states to implement ICNIRP and their power levels are more than ten times lower than NRPB in this frequency range [4] .

Also, there is some question as to the characteristics of the radar beam generated by the thousands of antennae on the PAR. Beams generated by conventional radar are in the form of simple waves, whereas the PAR beam is generated by many overlapping pulses that can strike a person thousands of times in a fraction of a second.

Some investigation into the accepted international standards is required in order to put these results into some kind of context. A recent report on the Physiological and Environmental Effects of Non-ionising Electromagnetic Radiation for the European Parliament [5] states:

“What distinguishes technologically produced electromagnetic fields from (the majority of) those of natural origin is their much higher degree of coherence. This means that their frequencies are particularly well-defined, a feature that facilitates the discernment of such fields by living organisms, including ourselves. This greatly increases their biological potency, and ‘opens the door’ to the possibility of frequency-specific, non-thermal influences of various kinds, against which existing Safety Guidelines – such as those issued by the International Commission for Non-ionising Radiation Protection (ICNIRP) - afford no protection. For these Guidelines are based solely on consideration of the ability of radio frequency (RF) and microwave radiation to heat tissue, and of extremely low frequency (ELF) magnetic fields to induce circulating electric currents in the interior of the body, both of which are known to be deleterious to health, if excessive.”

The report points out that the frequency-specific sensitivity of living organisms to ultra-low intensity microwave radiation was discovered over 30 years ago in Russia and there the exposure guidelines are approximately 100 times more stringent that those of ICNIRP. It also notes that some symptoms have been reported in epidemiological studies involving humans, animals and plant life connected with a radar operating at 154-162MHz, with a pulse repetition frequency of 24.4Hz - at a location where the intensity of the emitted radiation is comparable to that typically found at 150m from a base-station. Additional effects include [6] :

• Depressed nocturnal melatonin levels in cattle [7] .
  
• Less developed memory and attention span (as well as decreased endurance of their neuromuscular apparatus) of children living within a 20 km radius of the radar, subject to a maximum exposure of 0.00039 W m^-2.
  
• A six-fold increase in chromosome damage in cows exposed to a likely maximum intensity of 0.001 W m^-2. 

(The cited field intensities are estimated from information on the electric field intensity as a function of distance from the radar installation [8] ).

The Fylingdales radar operates by emitting a series of pulses and additional, perhaps more serious, problems may arise at frequencies around 17 Hz. As mentioned in the STOA report, this lies in the range of beta brain-wave activity and is close the frequency of a flashing visible light that can provoke seizures in people with photosensitive epilepsy. It is also the modulation frequency at which “there is a maximum in the expression of calcium ions from brain cells when they are irradiated with amplitude modulated, low intensity RF radiation over a wide range of carrier frequencies” and “any interference … could well undermine the integrity of the whole nervous system, although the extent to which this actually occurs is, at present uncertain, owing to a lack of the necessary research.”  The pulse repetition frequency of the radar is thought to be 27 pulses per second (at least, this was the documented frequency of the previous system [9] ) and it is not known whether there are any similar effects at or around this frequency that need to be examined closely.

Concerns about the effects of the electromagnetic radiation effects due to the radar were expressed by Yorkshire CND in its submission to the House of Commons Defence Committee on the upgrading of Fylingdales for the US Missile Defense Program (See First Report of Session 2002-3 Volumes I & II, HC 290-I and HC 290-II, published 29 & 30 January 2003). In response the MoD published for the first time results of emr levels measured around the base from 1991. These records show typical recorded levels of around 0.230 mW/cm² which is comparable with the reference level suggested by the ICNIRP of 0.225 mW/cm² for 450 MHz radar signals.

Radar power levels can be quoted as field strengths (V/m) or as power densities (mW/cm2). It is general practice amongst those who want to show how low their emissions are to quote in power density since this is proportional to the square of field strength, and therefore levels that are, say, ten times lower than the limit in volts per metre will be 100 times lower if expressed in mW/cm².

The maximum recorded levels are around 0.869  mW/cm² (location 26, Top of outside perimeter fence). This is 33% of the NRPB power density level or 58% of the NRPB electric field level.  However, it is 4.3 times the ICNIRP power density level or more than twice the ICNIRP voltage level.

In the report the MoD state:

(para 4 on p. Ev60) "It should be borne in mind that UK safety thresholds are based on NRPB guidelines and not those of ICNIRP..."

In fact the UK has failed to implement legislation based on the European Council Recommendation 1999/519/EC, which requires member states to implement ICNIRP safety thresholds (which are ten times lower than NRPB in the frequency range relevant to Fylingdales).

Cape Cod

In April 2001 the US Air Force agreed to conduct “time-domain measurements” on a similar radar installation (known as PAVE PAWS – Phased Array Warning System) at Cape Cod in the US. Local residents there are concerned about the radar because the area has some of the highest rates of cancer in the state. From 1993 to 1997, nine of the Cape's 15 towns had breast cancer rates at least 15 percent higher than the rest of the state. [10]

Richard Albanese, an Air Force scientist for more than 31 years, and others (including Professor Kurt Oughstun) are worried that the radar's phased wave fronts affect human tissue in ways that aren't yet understood. Albanese is reported as suggesting that the radar station should be shut down or moved and that ''I have to go with the concepts of the medical profession, which say that humans shouldn't be exposed to physical or chemical environments that have not been tested' . in the worst case the PAVE PAWS station could be causing a 21 percent increase in ’malignant disease' rates, a risk that would appear to warrant more study. ''In my experience working with military personnel ... misconceptions and errors tend to become entrenched in the organizational setting and do damage to medical practice'' he wrote. [11]

In a presentation given in February 2002 at the start of a series of experiments to measure the PAVE PAWS radar, Albanese said he has conducted animal testing that has shown animals suffering harm when exposed to phased array radar at levels 1,000 times below the current electrical health standards. [12] The question remains “why has the Air Force classified much of Albanese’s work?”

X-Band Radar

There may be additional problems. The UK government has already agreed that Fylingdales can be upgraded for use in the US missile defense (“Son of Star Wars”) system and it is still possible that a new high resolution phased-array X-band radar (XBRs) using high frequencies (5.2-8.5 GHz) and advanced radar signal processing technology may eventually be employed at Fylingdales to improve target resolution [13] . These systems emit a series of electromagnetic pulses over a 50^o field of view in azimuth and elevation, and can be rotated to track targets from any direction. When fully operational each system will include a radar mounted on pedestal, will need approximately 30 to 60 personnel to operate and will encompass an area of approximately 7 hectares (17.46 acres) for the radar alone and would need to be surrounded by a 150 m (500-foot) controlled area. [14]

XBRs have an average power of 170 kW and an antenna area of 123 m², which means a power-aperture product of about 20 million, but they usually incorporate a "thinned" array of only 1/5 of the total possible number of aerial elements (around 81,000) decreases the gain by a factor of 5.  In this case more energy goes into the radar beam sidelobes but does produce a narrower beam and provides greater tracking accuracy.

Questions have been raised regarding the possible danger to the health of people living close to these installations. The BMDO insists that the microwave leakage from these high power radars is safe – but independent investigations into possible health hazards need to be made.

The XBR BMDO fact sheet [14] states that “The exposure limits established by [the US standard] ANSI/IEEE C95.1 1999 are used to ensure that public health will not be impacted by EMR emitted from the XBR”.

Two major exposure environments are defined: inside and outside a controlled area of radius 150m. Security personnel would control the area to prevent any unauthorized access. It is claimed that outside the controlled area the EMR will be no higher than the power density levels specified in ANSI/IEEE C95.1 1999. The US Missile Defense Agency state that:

“There is a possibility that EMR may effect television reception out to a distance of 4 kilometers (about 2.5 miles) from the XBR and that occasional static may occur in some radios out to 7 kilometers (about 4.3 miles) from the XBR.”

Concluding remarks

The radar at RAF Fylingdales in North Yorkshire gives rise to a number of concerns:

• The effects on health from the electromagnetic radiation need further investigation – a fresh EMR survey of the site is needed to update and re-examine the data collected 8 years ago – especially as the accepted international standards are being challenged in the US and by those concerned about the health effects of mobile phone masts etc.;
• The Ministry of Defence needs to explain why it insists on referring to NRPB guidelines rather than those of the ICNIRP (recommended by the European Union). Could it be because the Fylingdales radar fails the ICNIRP standards but not those of the NRPB ?
• More studies are needed on the extent and effects due to the low frequencies around the pulse repetition rate (27 Hz) as these may be particularly harmful to biological organisms;
• The introduction of a proposed X-band radar would mean an increase in EMR levels possibly resulting in an increased danger to local inhabitants and wildlife.

Much more research is required into the extent of EMR pollution at Fylingdales, the effects of these EM fields at the frequencies encountered and a much more in depth study of the health effects of the proposed X-band radar system.

See also: reports on BBC program - "Health Fears Over RAF Radar"