The government agency which regulates cell phones says there's no basis for establishing a different safety threshold, but researchers from a group called the Environmental Health Trust believe the federal testing methods are flawed.
LLoyd Morgan is one of the researchers behind the study that looks at how the Federal Communications Commission sets radiation safety standards for cellphones. They found the FCC's tests are done on plastic heads the size of a 6 foot 2 inch, 220 pound man, which they say corresponds to just 3 percent of the population.
Because of that, the researchers believe the government's test underestimates the amount of radiation 97 percent of cellphone users are exposed to. Morgan says children are the most vulnerable.
"Children's tissues are more absorbent of the radiation, their skulls are thinner, their heads are smaller so they receive dramatically more radiation than adults," Morgan said.
But many scientists say there are no conclusive studies linking cancer and radiation.
"There are different types; the radiation from x-rays is ionizing radiation, the kind from cellphones is the same from microwave ovens, there is no good proof that that caused cancer," ABC News Health and Medical Editor Dr. Richard Besser said.
The cellphone industry organization agrees, saying, "The weight of scientific research has not linked the use of cellphones with any health concerns."
But Monday's report is unsettling for some cellphone users ABC7 talked with.
"It's not going to make me put down my cellphone, it's just one of those other carcinogens we'll have to deal with," Karen Tannenbaum said.
Both the federal government and the authors of Monday's study agree that those who want to reduce radiation exposure can hold their cellphones away from the head and body, or use a speaker or hands-free device.