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1. Two groups of 18 people were exposed to simulated 
mobile phone signals under laboratory conditions 
while they performed cognitive function tests. There 
were no changes in the subjects' ability to recall 
words, numbers, or pictures, or in their spatial 
memory, but they were able to make choices more 
quickly in one visual test when they were exposed to 
simulated mobile phone signals. This was the only 
change noted among more than 20 variables 
compared.
3
 
2. In a study of 209 brain tumor cases and 425 matched 
controls, there was no increased risk of brain 
tumors associated with mobile phone use. When 
tumors did exist in certain locations, however, they 
were more likely to be on the side of the head 
where the mobile phone was used.
Because this occurred in only a small number of cases, the 
increased likelihood was too small to be statistically 
significant.
4
 
In summary, we do not have enough information at this 
point to assure the public that there are, or are not, any low 
incident health problems associated with use of mobile 
phones. FDA continues to work with all parties, including 
other federal agencies and industry, to assure that research 
is undertaken to provide the necessary answers to the 
outstanding questions about the safety of mobile phones. 
What is known about cases of human 
cancer that have been reported in users of 
hand-held mobile phones?
Some people who have used mobile phones have been 
diagnosed with brain cancer. But it is important to 
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