Exposures of the general public to radio waves at locations near 20 randomly selected GSM microcell and picocell base stations in the UK have been assessed in the context of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. Compliance distances were calculated for the antennas of the base stations from their reported radiated powers. Under pessimistic assumptions that would maximise exposures, the minimum height at which the general public reference level could potentially be exceeded near any of the base station antennas was calculated to be 2.4 m above ground level. The power densities of the broadcast carriers transmitted by the base stations have been measured and scaled to include all other possible carriers. Exposures were generally in the range 0.002-2% of the ICNIRP general public reference level, and the greatest exposure quotient near any of the base stations was 8.6%. Exposures close to microcell base stations were found to be generally greater than those close to macrocell base stations.

An instrument is described for measurement of body current based on the use of a clamp-on RF current transformer, of a type used in EMC (electromagnetic compatibility) testing which can be worn around a subject's ankle. This transformer and its associated electronics are termed a personal current meter or PCM. The prototype instrument gave good performance over the current range 8-1000 mA for a frequency range of 0.1-80 MHz, and uses a digital display. The design of a prototype PCM is discussed, together with a description of the test methods used to assess the performance of the instrument in the laboratory.

The use of personal monitors for the assessment of exposure to radiofrequency fields and radiation in potential future epidemiological studies of occupationally exposed populations has been investigated. Data loggers have been developed for use with a commercially available personal monitor and these allowed personal exposure records consisting of time-tagged measurements of electric and magnetic field strength to be accrued over extended periods of the working day. The instrumentation was worn by workers carrying out tasks representative of some of their typical daily activities at a variety of radio sites. The results indicated significant differences in the exposures of workers in various RF environments. A number of measures of exposure have been examined with a view to assessing possible exposure metrics for epidemiological studies. There was generally a good correlation between a given measure of electric field strength and the same measure of magnetic field strength.

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The United Kingdom Childhood Cancer Study, a population-based case -control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0 -14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure 520 V m 71 to those in a reference category of exposure 510 V m 71 , odds ratios of 1.31 (95% confidence interval 0.68 -2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73 -2.39) for total leukaemia, 2.12 (95% confidence interval 0.78 -5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77 -2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49 -1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56 -1.54) for total leukaemia, 1.43 (95% confidence interval 0.68 -3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59 -1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m 71 were close to unity for all disease categories, never differing significantly from one.