There is currently growing public concern about the number of base station masts that are being erected, and the effect these may have on both health and on property values. The field strengths from masts is low and is unlikely to be more of a problem than any other form of RF data communications., however increasing worries are surfacing about all levels of RF energy, especially when digital signal bursts are transmitted. When one looks at what few epidemiological studies that have been done to date on RF/MW(radio frequency electromagnetic energy) human exposure, there is ample evidence of adverse health effects to warrant concern.
    The UK NRPB regularly uses the words "substantiated", "firm", and "proven" evidence regarding the results of epidemiological (i.e. of populations of people) studies. Epidemiological studies on human populations do not, and generally can not, look for "proof" or "substantiation" but increases in incidence of a disease, or relative risk ratios.
    Epidemiological studies on tobacco and asbestos did not "prove" that these carcinogens cause cancer; they do show, however, a significantly increased risk of developing cancer from exposure. This is not "substantiation", but that did not prevent the health authorities from taking corrective action. It is unfortunate that with electromagnetic radiation, however, industry and its supporters insist an absolute cause - effect relationship must be proven before corrective action be taken. The following recent studies do not "substantiate" anything in relation to exposure to RF/MW; they are dealing with the increase in incidence of adverse health effects such as cancer. They are, however, relevant and should be taken into account when formulating policy:
    a) A preliminary study by Dr Bruce Hocking compared cancer rates in three municipalities within a 4 km radius of Sydney TV towers with rates in adjacent areas further away. The study found children living within the 4 km radius had a relative risk of 1.6 for leukaemia, compared with the control group. The RR for mortality was higher at 2.3, and highest at 2.8 for lymphoblastic leukaemia. [25] The calculated power levels were around 0.02 to 8 mW/cm2.
    b) In 1987, a similar study identified higher rates of cancer among those living near the TV and radio broadcast towers in Hawaii. Drs. Anderson and Henderson of the Hawaii Department of Health found in residential areas with 12 communication towers, a relative risk for cancer, including leukaemia, of 1.375 (37.5% increase). [26]
    c) A study of cancers around the BBC Sutton Coldfield transmitter mast (Dolk, et al, 1997) found a statistically significant doubling of adult leukaemia within 2 km, and a significant decline in risk with distance up to 10 km from the mast was also found for skin cancer. The decline with distance was also observed at 20 other high power masts, but no significant increase in overall incidence was found. [27]
    d) An earlier study in 1982, conducted by Dr Morton of the University of Oregon's Health Science Centre found parallel trends in his study of cancer and broadcast radiation in Portland. [28]
    e) Dr. Stanislaw Szmigielski, a leading epidemiologist with the Centre for Radiobiology and Radiation Safety at the Military Institute of Hygiene and Epidemiology, Warsaw, Poland has been the team leader for an on-going study of the health effects of RF/MW exposure of military personnel in Poland for the whole military population. His research found that young military personnel exposed to RF/MW radiation had more than eight times the expected rate of leukaemia and lymphoma. Careful surveys of exposure revealed that 80 - 85% of the personnel were exposed to an average of less than 42 microwatts/sq. cm., with a median point near 7 microwatts/sq. cm. [8]
    f) Quellet-Hellstrom and Stewart (1993) found a statistically significant 3.3 fold increase of miscarriage amongst U.S. physiotherapists using microwave diathermy compared to a non-exposed control group. The incidence increased with the number of monthly treatments, which could suggest a cumulative effect. With about 10 treatments per month, the exposure was about 0.04 to 0.56 microwatts/sq. cm. [29]
    g) Shandala et. al. (1979) found that calcium ion efflux varies in living animal cells at 10 micro watts/sq.cm. and this level also produces brain activity changes. [30]
    h) Prof. von Klitzing (1995) found changes to human brain EEG with a signal of 217 Hz modulation on a 150 megahertz (MHz) carrier with an external exposure of about 2.5 microwatts/sq.cm. [31]
    i) Professor John Goldsmith, at Ben Gurion University of the Negev, Israel, has collected evidence of several exposures to microwaves which produced elevated risks of a wide range of cancers, including childhood leukaemia in children of staff, and cancers in the staff and partners at the U.S. Embassy in Moscow and other eastern European U.S. embassies. These cancers were associated with a reported maximum exposure of between 5 and 15 microwatts/sq.cm. and mean exposures between 1 and 2.4 mW/cm2, recorded near the outside walls of the embassy. Personnel exposures inside the building were estimated between 0.2 and 0.5 mW/cm2. [32]
    j) To quote from Dr. Neil Cherry's (New Zealand) recent book: [33] "With these and dozens of other epidemiological studies of large populations and large numbers of workers occupationally exposed to RF/MW radiation, showing statistically significant increases of a wide spectrum of cancers, there can be little or no doubt that chronic low level exposure to RF/MW radiation produces increased cancer risk."