186Section 14exposures characteristic of wireless phones have yieldedconflicting results that often cannot be repeated in otherlaboratories. A few animal studies, however, havesuggested that low levels of RF could accelerate thedevelopment of cancer in laboratory animals. However,many of the studies that showed increased tumordevelopment used animals that had been geneticallyengineered or treated with cancer-causing chemicals so asto be pre-disposed to develop cancer in absence of RFexposure. Other studies exposed the animals to RF for upto 22 hours per day. These conditions are not similar to theconditions under which people use wireless phones, sowe don't know with certainty what the results of suchstudies mean for human health.Three large epidemiology studies have been publishedsince December 2000. Between them, the studiesinvestigated any possible association between the use ofwireless phones and primary brain cancer, glioma,meningioma, or acoustic neuroma, tumors of the brain orsalivary gland, leukemia, or other cancers. None of thestudies demonstrated the existence of any harmful healtheffects from wireless phones RF exposures. However,none of the studies can answer questions about long-termexposures, since the average period of phone use in thesestudies was around three years.What research is needed to decide whether RF exposurefrom wireless phones poses a health risk?A combination of laboratory studies and epidemiologicalstudies of people actually using wireless phones wouldprovide some of the data that are needed. Lifetime animalexposure studies could be completed in a few years.
