User Manual

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4.Whataretheresultsoftheresearchdonealready?
Theresearchdonethusfarhasproducedconflictingresults,andmanystudieshave
sufferedfromflawsintheirresearchmethods.Animalexperimentsinvestigatingthe
effectsofradiofrequencyenergy(RF)exposurescharacteristicofwirelessphoneshave
yieldedconflictingresultsthatoftencannotberepeatedinotherlaboratories.Afew
animalstudies,however,
havesuggestedthatlowlevelsofRFcouldacceleratethe
developmentofcancerinlaboratoryanimals.
However,manyofthestudiesthatshowedincreasedtumordevelopmentused
animalsthathadbeengeneticallyengineeredortreatedwithcancer‐causingchemicals
soastobepredisposedtodevelopcancerintheabsence
ofRFexposure.Other
studiesexposedtheanimalstoRFforupto22hoursperday.Theseconditionsarenot
similartotheconditionsunderwhichpeopleusewirelessphones,sowedon’tknow
withcertaintywhattheresultsofsuchstudiesmeanforhumanhealth.Threelarge
epidemiologystudies
havebee npublishedsinceDecember2000.Betweenthem,the
studiesinvestigatedanypossibleassociationbetweentheuseofwirelessphonesand
primarybraincancer,glioma,meningioma,oracousticneu‐roma,tumorsofthebrain
orsalivarygland,leukemia,orothercancers.Noneofthestudiesdemonstratedthe
existenceofany
harmfulhealtheffectsfromwirelessphoneRFexposures.However,
noneofthestudiescananswerquestionsaboutlong‐termexposures,sincethe
averageperiodofphoneuseinthesestudieswasaroundthreeyears.

5.WhatresearchisneededtodecidewhetherRFexposurefromwireless
phonesposesahealthrisk?
Acombinationoflaboratorystudiesandepidemiologicalstudiesofpeopleactuallyusing
wirelessphoneswouldprovidesomeofthedatathatareneeded.Lifetimeanimal
exposurestudiescouldbecompletedinafewyears.However,verylargenumbersof
animalswouldbeneededtoprovidereliableproofofacancerpromoting
effectifone
exists.Epidemiologicalstudiescanprovidedatathatisdirectlyapplicabletohuman
populations,but10ormoreyears’follow‐upmaybeneededtoprovideanswersabout
somehealtheffects,suchascancer.Thisisbecausetheintervalbetweenthetimeof
exposuretoacancer‐causing
agentandthetimetumorsdevelop‐iftheydo‐maybe
many,manyyears.Theinterpretationof epidemiologicalstudiesishamperedby
difficultiesinmeasuringactualRFexposureduringday‐to‐dayuseofwirelessphones.
Manyfactorsaffectthismeasurement,suchastheangleatwhichthephoneisheld,
or
whichmodelofphoneisused.

6.WhatisFDAdoingtofindoutmoreaboutthepossiblehealtheffectsof
wirelessphoneRF?
FDAisworkingwiththeU.S.NationalToxicologyProgramandwithgroupsof
investigatorsaroundtheworldtoensurethathighpriorityanimalstudiesareconducted
toaddressimportantquestionsabouttheeffectsofexposuretoradiofrequencyenergy
(RF).FDAhasbeenaleadingparticipantintheWorldHealthOrganizationInternational
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