§ Mr. Skeetasked the Secretary of State for the Home Department what evidence there is that the frequency of 928MHz offered for open channel radio will induce tumours in operators using transmission and receiving equipment.
§ Mr. RaisonAs I indicated in my reply to a question by my hon. Friend the Member for Sudbury and Woodbridge (Mr. Stainton) on 11 November—[Vol. 992, c.149.]—we sought advice on this matter from the National Radiological Protection Board which published the following statement last week
Objections have been raised to the Government's preferred frequency for a public 'Open channel' radio service (around 928 MHz UHF) on the grounds of possible health hazards. The specific dangers cited are the induction of brain tumours and cataracts in the eyes.The Board considers that there is no scientific evidence that exposure to microwaves or radiofrequencies will cause brain tumours cm other cancers or that there is any evidence which indicates the existence of special hazards from radiation in the frequency range 150 to 1200 MHz.172WExposure to very high power levels of microwaves has been shown to cause cataracts in animals and may be inferred to give rise to a similar effect in humans, but the exposure must be such as to raise the temperature of the eye by at least 4°C for more than ten minutes. The normal temperature of eyes and body fluctuates daily by about 1–2°C, and possibly more under the influence of physical exertion. For hand-held radio transmitters with total effective radiated powers of less than 3 watts, studies indicate that the temperature rise in the eyes will not be more than 1.0°C when their aerials are held no closer than 1 cm to the face, and the transmitter operated continuously for several minutes. Direct comparisons between hand-held transmitters has shown little difference in the total power absorbed by the head at 150 MHz, 450 MHz and 900MHz or in the maximum values of the power absorption. There is no reason to expect significantly different results at other frequencies in this range.There is unlikely to be any direct danger to health from handheld transmitters used for the 'Open Channel' communication in any part of the radiofrequency spectrum, when the effective radiated powers are less than 3 watts and the transmitters and their aerials are kept more than 1 or 2 cm from the head. In the case of mobile transmitters with effective radiated powers of 25 watts it would be inadvisable to place the head closer than about 10 cm to the aerial for any length of time.