Mobile phones and health: an interim report
Protective devices
The debate over possible adverse health effects of mobile phones has resulted in the production and use of devices that aim to reduce or block the radiation emitted by the handset and hence that absorbed by the user. There are two main categories: hands-free kits (HFKs), and shields and attachments.
Hands-free kits
Great public confusion has been generated by the conflicting results of studies that have investigated these devices. Below we briefly outline the main findings from the studies:
- April 2000: UK Consumers’ Association(12) reported that the earpiece wire on HFKs may act as an aerial, channelling three times as much radiation into the user’s head. Recommendations included reducing mobile phone use, and ceasing use of HFKs.
- May 2000: The Stewart Report(3) concluded that there is insufficient published information about the measurement methods used in the research to date to form a clear view, and recommended that the Government establish a national system which enables independent testing of shielding devices and HFKs to be carried out, and allows clear information to be given about the effectiveness of these devices. A kite mark or equivalent should also be introduced.
- August 2000: Australian Consumers’ Association(14) concluded that HFKs can reduce exposure to electromagnetic radiation. Recommendations included purchasing a HFK, avoidance of mobile phone contact with the body, and minimisation of phone usage.
- August 2000: The Department of Trade and Industry’s (DTI) study(15) concluded that “in what would be considered their normal mode of use, personal hands-free kits offer very substantial reductions in SAR compared to the normal use of the phone against the head”. With a kit in use, the maximum body absorption depends on where the phone is placed – SAR levels are reduced when the phone is placed with the keypad pointing towards the body. Recommendations to reduce exposure as a precautionary measure included letting the ear-piece cable hang down naturally from the ear, keeping the cable away from the phone’s antenna and not placing the phone directly against the body.
- November 2000: Further UK Consumers’ Association research(16) concluded that all HFKs they tested could lower the levels of radiofrequency emissions, but they could also increase them by anything from 50% to 250% (although still within the ICNIRP guidelines). This depends on the phone, the kit, the height of the user, and where the phone is positioned. In particular the distance between the handset and the earpiece was found to influence RF emission from the earpiece, although it is not possible for an individual to work out the best position to minimise the effect. The report noted that a potential solution to the higher level of emissions would be the fitting of a ferrite ring (metallic/ceramic compounds designed to absorb electromagnetic fields) on the HFK wire below the ear as this seems to reduce the levels of radiation measured in the ear. The report recommended that the Government devise a new standard for testing HFKs, and that the quantity and duration of calls be kept to a minimum whether a kit is used or not.
i. There is no standard for testing HFKs, hence the DTI and Australian Consumers’ Association measured SAR, whilst the Consumers’ Association measured electromagnetic emissions. The DTI argues that SAR is the rational and scientific way to proceed, and that emissions say little about absorption in the head which is the key health risk factor.
ii. The UK Consumers’ Association identified potential problems with the SAR test used by the DTI, including the rig hindering the wire from hanging straight down as it would in normal use and where their own tests identified the highest RF emissions, and potential problems with interference from other electrical systems in the environment (electromagnetic compatibility problems).
The Government considers that use of HFKs is a matter of personal choice: the public has been supplied with relevant information so that they can make an informed choice, as recommended by the Stewart Report.(3) However, with no standard testing procedures or standards, and no regulatory requirements for the manufacturers of the HFK, the decision to use one, and which one to purchase is difficult to make. The DTI are “taking forward” the recommendation from the laboratory that conducted their research that the European CENELEC draft standard(54) for testing human exposure to EMFs should be developed for HFK measurement.
Shields and attachments
Shields are cases or attachments for mobile phone handsets and their antennae that aim to reduce the exposure to electromagnetic emissions. The Stewart Report(3) concluded that in practice there would be very little reduction in the exposure received by most users through the use of a shield, and that all but one shield that they tested had no physical basis for their proposed effects. The Consumers’ Association(12) concluded that although two of the three shields they tested did reduce emissions, this would result in the phones having to increase their power to maintain their RF signal to the base station. For this reason, phones’ reception could be impaired when they were a long way from a base station or in buildings, cars, etc. The Stewart Report(3) predicted that widespread use of shields could have adverse effects on the environment since more base stations would need to be erected to maintain the quality of communication in phones whose optimum signals were reduced.
The Government has confirmed that research into shields and other absorption devices will be conducted. They do not recommend the use of any devices that have not been thoroughly and independently tested. The Federation of the Electronics Industry, the ‘voice of the UK electronics industry’ (FEI) states that it is a matter of consumer choice to use a HFK or shield. Devices which have not been approved by the mobile phone manufacturers for use with mobile phones, might impair the operating efficiency of the phone, so the FEI advises users to consult their dealer about suitable kits for their model of phone.