United States must comply with FCC safety guidelines that limit RFexposure. FCC relies on FDA and other health agencies for safetyquestions about devices.FCC also regulates the base stations that the device networks relyupon. While these base stations operate at higher power than do thedevices themselves, the RF exposures that people get from these basestations are typically thousands of times lower than those they can getfrom devices. Base stations are thus not the primary subject of thesafety questions discussed in this document.What are the results of the research done already?The research done thus far has produced conflicting results, and manystudies have suffered from flaws in their research methods. Animalexperiments investigating the effects of radio frequency energy (RF)exposures characteristic of devices have yielded conflicting results thatoften cannot be repeated in other laboratories. A few animal studies,however, have suggested that low levels of RF could accelerate thedevelopment of cancer in laboratory animals. However, many of thestudies that showed increased tumor development used animals thathad been genetically engineered or treated with cancer-causingchemicals so as to be pre-disposed to develop cancer in absence of RFexposure. Other studies exposed the animals to RF for up to 22 hoursper day. These conditions are not similar to the conditions under whichpeople use devices, so we don't know with certainty what the results ofsuch studies mean for human health.Three large epidemiology studies have been published since December2000. Between them, the studies investigated any possible associationbetween the use of devices and primary brain cancer, glioma,meningioma, or acoustic neuroma, tumors of the brain or salivary