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radiation, but only after 24 hours of exposure. It is possible that exposing
the test cells to radiation for this long resulted in heating. Since this assay
is known to be sensitive to heating, heat alone could have caused the
abnormalities to occur. The data already in the literature on the response
of the micronucleus assay to RF are conflicting. Thus, follow-up research
is necessary.
1
Two other studies of interest have been reported recently in the
literature:
1. Two groups of 18 people were exposed to simulated mobile phone
signals under laboratory conditions while they performed cognitive
function tests. There were no changes in the subjects’ ability to recall
words, numbers, or pictures, or in their spatial memory, but they were
able to make choices more quickly in one visual test when they were
exposed to simulated mobile phone signals. This was the only change
noted among more than 20 variables compared.
2
2. In a study of 209 brain tumor cases and 425 matched controls, there was
no increased risk of brain tumors associated with mobile phone use.
When tumors did exist in certain locations, however, they were more
likely to be on the side of the head where the mobile phone was used.
Because this occurred in only a small number of cases, the increased
likelihood was too small to be statistically significant.
3
In summary, we do not have enough information at this point to assure
the public that there are, or are not, any low incident health problems
1.Tice et al. Tests of mobile phone signals for activity in genotoxicity and other labora-
tory assys. In: Annual Meeting of the Environmental Mutagen Society; March 29, 1999,
Washington, D.C.: and personal communication, unpublished results.
2.W, Iwi, G, Davies-Smith, A, Wesnes, K, Butler, S, Lim, E, and Varey, A. Effect of a 915-
MHz simulated mobile phone signal on cognative function in man. Int. J. Radiat. Biol.,
April 8, 1999.
3.Hardell, L, Nasman, A, Pahlson, A, Hallquist, A and Mild, KH. Use of cellular tele-
phones and the risk for brain tumors: a case-control study, Int. J. Oncol., 15: 113-116,
1999.
