138 Health and Safety Informationanswers about some health effects, such as cancer. This isbecause the interval between the time of exposure to acancer-causing agent and the time tumors develop - ifthey do - may be many, many years. The interpretation ofepidemiological studies is hampered by difficulties inmeasuring actual RF exposure during day-to-day use ofwireless phones. Many factors affect this measurement,such as the angle at which the phone is held, or whichmodel of phone is used.What is FDA doing to find out more about the possiblehealth effects of wireless phone RF?FDA is working with the U.S. Toxicology Program andwith groups of investigators around the world to ensurethat high priority animal studies are conducted toaddress important questions about the effects of exposureto radio frequency energy (RF).FDA has been a leading participant in the World HealthOrganization International Electromagnetic Fields(EMF) Project since its inception in 1996. An influentialresult of tis work has been the development of a detailedagenda of research needs that has driven theestablishment of new research programs around theworld. The project has also helped develop a series ofpublic information documents on EMF issues.FDA and the Cellular Telecommunications & InternetAssociation (CTIA) have a formal Cooperative Researchand Development Agreement (CRADA) to do research onwireless phone safety. FDA provides the scientific
