Like we talked about in the last section, SAR limits that are reported are the maximum possible radiation emitted from the device, however, this level is not what is common with the regular use of the device. Just because one cell phone has a higher maximum SAR level, doesn’t mean that the radiation level of normal use isn’t higher or lower than another device with a different maximum SAR level.
An analysis of data from NCI's Surveillance, Epidemiology, and End Results (SEER) Program evaluated trends in cancer incidence in the United States. This analysis found no increase in the incidence of brain or other central nervous system cancers between 1992 and 2006, despite the dramatic increase in cell phone use in this country during that time (22).

As in the NTP study, Ramazzini investigators detected statistically elevated rates of heart schwannomas in male rats at the highest dose. They also had weaker findings linking RF exposure to cancer of glial cells in the brain, which were limited to females. Ronald Melnick, a retired NTP toxicologist who designed the NTP study, says a measure of consistency between the two studies is important, because “reproducibility in science increases our confidence in the observed results.”
In 2011, the American Cancer Society (ACS) stated that the IARC classification means that there could be some cancer risk associated with radiofrequency radiation, but the evidence is not strong enough to be considered causal and needs to be investigated further. Individuals who are concerned about radiofrequency radiation exposure can limit their exposure, including using an ear piece and limiting cell phone use, particularly among children.
* This specification establishes the requirements for heat-sealable, electrostatic protective, flexible barrier materials used for the military packaging of microcircuits, sensitive semiconductor devices, sensitive resistors, and associated higher assemblies. In addition, the type I materials provide for water vapor-proof protection and attenuation of electromagnetic radiation.

And even with these unusually high levels of exposure, the links to cancer were still “mostly equivocal, or ambiguous,” according to the FDA’s statement. In fact, the rats exposed to cell phone radiation actually appeared to live longer than the ones that weren’t, a finding that the FDA’s Shuren says the agency is assessing. The difference could simply be the result of chance, STAT News reports.
The only consistently recognized biological effect of radiofrequency radiation in humans is heating. The ability of microwave ovens to heat food is one example of this effect of radiofrequency radiation. Radiofrequency exposure from cell phone use does cause heating to the area of the body where a cell phone or other device is held (e.g., the ear and head). However, it is not sufficient to measurably increase body temperature. There are no other clearly established effects on the human body from radiofrequency radiation.