Planning

The Office of Communications (Ofcom) is responsible for the management of the civil radio spectrum. As part of that function it helps prevent interference to radio services and measures radio emissions.

The Stewart Report

The Stewart group was set up to examine public health concerns about mobile phone emissions. The Stewart Report said that there was no evidence to conclude that there was any risk to public health from mobile phone base station emissions as exposures are expected to be a small fraction of the guidelines. Nevertheless, the report said that, as part of its recommended precautionary approach, there should be an independent audit of base stations. In response to the report's recommendation the government asked the Radiocommunications Agency (RA), a predecessor of Ofcom, to implement a national measurement programme to ensure that emissions from base stations do not exceed guidelines.

The Stewart Report went on to say that particular attention should be paid to the auditing of base stations near schools and other sensitive areas.

How the survey sites were chosen

The RA had a database of mobile phone base station sites at schools. A sample of these sites was audited as part of the national measurement programme. Sites were chosen randomly from this site list, although schools were also able to volunteer to have an audit carried out, as long as validity of the sample was not compromised.

Scope of survey

The surveys started in autumn 2000. RA engineers measured the frequency and the power density of transmissions. Results were referenced to and presented alongside the International Commission on Non-Ionizing Radiation Protection (ICNIRP) recommended investigation levels.

Measurement considerations

The amount of radio energy radiated from the antenna main beam within the school boundary is dictated by the radio power fed to the antenna, the antenna elevation and its radiation pattern, which together dictate where the main beam hits the ground. The main beam reaches the ground between 50 and 300 metres from the foot of the mast.

The results

The survey results were made available to headteachers on the day of the audit. All results were posted on the agency's website and can now be found at www.ofcom.org.uk/static/archive/ra/topics/mpsafety/school-audit/audit.htm.

The government has issued advice for schools and local education authorities on mobile phones and base stations. This is available at www.teachernet.gov.uk/management/atoz/m/mobilephonesandbasestations.

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