Health and Safety Information135What research is needed to decide whether RFexposure from wireless phones poses a healththreat?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.However, very large numbers of animals would be needed toprovide reliable proof of a cancer promoting effect if oneexists. Epidemiological studies can provide data that isdirectly applicable to human populations, but ten or moreyears’ follow-up may be needed to provide answers aboutsome health effects, such as cancer. This is because theinterval between the time of exposure to a cancer-causingagent and the time tumors develop - if they do - may bemany, many years. The interpretation of epidemiologicalstudies is hampered by difficulties in measuring actual RFexposure during day-to-day use of wireless phones. Manyfactors affect this measurement, such as the angle at whichthe phone is held, or which model of phone is used.What is FDA doing to find out more about thepossible health effects of wireless phone RF?FDA is working with the U.S. Toxicology Program and withgroups of investigators around the world to ensure that highpriority animal studies are conducted to address importantquestions about the effects of exposure to radio frequencyenergy (RF).FDA has been a leading participant in the World HealthOrganization International Electromagnetic Fields (EMF)Project since its inception in 1996. An influential result of tiswork has been the development of a detailed agenda ofresearch needs that has driven the establishment of newresearch programs around the world. The project has also
