Can Cell Phones Harm Our Health

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					Can Cell Phones Harm Our Health?
The National Research Center for Women & Families
and the Cancer Prevention and Treatment Fund

Diana Zuckerman, PhD, Brandel France de Bravo, MPH, Rachel Lieberman, BA,
and Megan Cole, BA

                                                Updated November 2010

If you watch the news or read magazines      research is likely to conclude whether
and newspapers, you’ve probably seen         cell phones cause cancer or not.
articles claiming that “cell phones are      However, the evidence indicates cause
dangerous” and other articles claiming       for concern. In addition to possibly
that “cell phones have been proven           increasing our risk of cancer, new
safe.” It’s hard to know what to             research shows that cell phone radiation
believe—especially when we’ve grown          (known as Radio Frequency-
so dependent upon these convenient           Electromagnetic Radiation or RF-EMR)
communication devices. Should we be          may have other negative health effects,
worried?                                     including harming sperm, reducing male
                                             fertility, harming your quality of sleep,
Have you ever read the fine print in your    worsening migraines, and even changing
cell phone manual? All manuals say not       the behavior of the cells inside your
to hold the phone next to your ear, but      body.
how many of us actually talk on cell
phones while holding them an inch            What Does Research Tell Us
away?                                        about Cell Phones and Tumors?
In July 2008, Dr. Ronald Herberman,          Three years ago, a review of 18 studies
Director of the University of Pittsburgh     of cell phones and brain tumors,
Cancer Institute, made quite a stir in the   published in Occupational and
media when his warning to staff was          Environmental Medicine by Lennart
made public: he told his employees that      Hardell and his colleagues, concluded
cell phone radiation may present more of     that studies of individuals using cell
a health risk than we had thought. He        phones for more than 10 years “give a
advised that rather than wait for            consistent pattern of an increased risk for
definitive studies, we should                acoustic neuroma and glioma,” with the
immediately curb our cell phone use,         risk being highest for a tumor on the
and especially cell phone use by             same side of the head that the phone is
children.1                                   used.2 Gliomas are the most common
                                             cancerous brain tumor, and the majority
The extensive use of cell phones is a        of gliomas are malignant (and usually
relatively recent phenomenon, and since      fatal). Acoustic neuromas are benign
cancers usually take at least 10-20 years    tumors of the acoustic nerve that can
to develop, it will be years before          cause deafness. The studies were

conducted in the United States, Sweden,      which side of the head the phone was
Finland, the U.K., Germany, and Japan.       used and whether the tumor was on the
                                             same side, which was a key variable
Around the same time, cell phone             predicting tumors in other studies.
companies insisted that the evidence
shows that their cell phones are safe.       The Latest, Largest Studies Give
Cell phone companies tend to focus on        Mixed Results and Cause for
the studies they funded themselves and       Concern
that draw conclusions that will keep their
business booming. A good example is a        In 2009, Australian neurosurgeon, Vini
study by Schuz and colleagues at the         Khurana, together with Lennart Hardell
Danish Cancer Society and International      and other scientists, conducted a meta-
Epidemiology Institute, but funded by        analysis of 11 studies published in peer-
cell phone companies.3                       reviewed journals on long-term cell
                                             phone use and the risk of developing
This study included more than 420,000        brain tumors. To be included in this
Danes who first started a cell phone         meta-analysis, the studies had to follow
subscription between 1982 and 1995,          cell phone users for at least ten years and
and were followed through 2002 to            document on which side of the head
determine if they were diagnosed with        participants held their phones. Three
acoustic neuroma, gliomas, or other head     studies did not meet the second of the
cancers. That sounds impressive, but         two criteria and were therefore excluded.
while the study describes that it followed   The authors concluded, in their article in
cell phone users “for up to 21 years,” the   Surgical Neurology, that using a cell
average subscription was started only 8.5    phone for ten or more years
years before the study was completed,        “approximately doubles the risk of being
and only 3% had started using cell           diagnosed with a brain tumor” on the
phones 15 or more years before the data      side of the head where the cell phone
were analyzed. Therefore, this study did     user holds the phone.4
not evaluate people using cell phones for
a long enough period to determine if cell    The Interphone Project
phone use causes cancer. Individuals
with corporate accounts were excluded        More than half of the studies in Khurana
from the sample, which is also a             and Hardell’s meta-analysis were from
shortcoming because they were the early      the Interphone Project, which is an
adopters and heaviest users of cell          international effort to investigate
phones.                                      possible tumor risks associated with the
                                             use of mobile phones in 13 countries.
This study reported no increased             The U.S. is not participating in that
likelihood of brain cancers for those who    research. A shortcoming of the research
used cell phones for more than 10 years;     is that Interphone studies define “regular
however, 10 years is not very long and       cell phone use” as at least one call per
cell phone usage in the 1980s and 1990s      week for at least 6 months, and long-
was much less frequent than it is today.     term use is defined as at least one call
Another shortcoming of this study is that    each week for at least 6 years.
the researchers did not evaluate on          Obviously, this is much lower usage

than is typical today. The Interphone        brain cancer would tend to recall higher
Project is funded by international           cell phone usage because of media
organizations (World Health                  attention to the risk of cell phones, or
Organization, European Commission),          mistakenly recall that they used the
cell phone companies, and with taxpayer      phone on the side of their head where the
money from participating countries.          tumor was found.

The Interphone project has been              However, numerous other researchers
underway for more than ten years and         questioned the way in which the
has cost more than $30 million. Results      Interphone data were calculated, saying
were supposed to be published in 2003        it underestimated risk. In addition,
and 2006, but were repeatedly delayed        several researchers point out that people
due to the need for more research,           tend to hold a cell phone with the same
conflicts over how to interpret the          hand almost all the time, and therefore
research, and changes in leadership.         would consistently use the phone on that
                                             side of their head.
In May 2010, new Interphone study
results were finally released, with          After evaluating the size of potential
findings about longer-term use of cell       biases in the Interphone analysis,
phones. However, the results were            Morgan, Kundi, and Carlberg used a
unclear, concluding that “the possible       “correction factor” to adjust these risks
effects of long-term heavy use of mobile     and concluded that the brain tumor risk
phones require further investigation.” No    increased significantly with greater cell
increase in risk for brain tumors was        phone use.6 For example, according to
seen for those who regularly used cell       the original Interphone calculation, a
phones. In fact, overall, people who         2008 study led by Hepworth and
used cell phones actually were less likely   colleagues showed that regular cell
to develop a brain tumor. However,           phone use for 10 years or more increased
people with the greatest use of cell         a person’s risk of glioma by 24% on the
phones (a total of 1640 hours or more        side of the head where the cell phone is
over a 10 year period—about 27 minutes       held. When the risk calculations were
per day) increased their risk of glioma      corrected, the risk of glioma increased to
by 40%, compared to people who did           55%, a statistically significant increase,
not use a cell phone regularly.5             which means that it is unlikely to have
                                             occurred by chance.
Controversies on Cell Phone Research
Results                                      Similarly, a 2007 Interphone study by
                                             Anna Lahkola and colleagues showed
Despite the increase in brain tumor risk     that 5 to 9 years of cell phone use
for people with the highest cell phone       increased the risk of glioma by a non-
use, the Interphone researchers stated       significant 10% on the side of the head
that this finding could be due to biases     where the cell phone was used, but this
and errors in the data and that their        increased to a statistically significant
results were inconclusive. For example,      38% increased risk when the risk
the Interphone analysis questioned           calculations were redone.7
whether individuals diagnosed with

Most important, there is an inevitable       However, for other parts of the brain
problem with any studies conducted so        exposed to radiation from cell phones
far: cancer usually takes 15-20 years to     (the temporal lobe, parietal lobe, and
develop. For example, most smokers           cerebellum), there was no increase in
start smoking in their teens, but even       cancer rates. Cancer takes a long time to
heavy smokers are rarely diagnosed with      develop and people have only recently
lung cancer until they are in their 40s or   begun to use cell phones regularly. The
50s. In fact, two out of every three cases   true effect of cell phones on brain cancer
of lung cancer are diagnosed in people       will be clearer in years to come, so
65 or older. This means that any cancer      continued research is greatly needed.
risk from cell phone use is likely to be
difficult to measure until at least 10-20    Beyond Brain Tumors: Other
years from now.                              Health Concerns
On the other hand, 10 or 20 years from       While disagreements over the global
now it may be difficult to study people      Interphone results continue, several
who don’t use cell phones, in                countries participating in the project,
comparison to those that do. And, even       including Sweden, Denmark, France and
the Interphone studies may have              Israel, have published their own results
underestimated the brain tumor risk          on brain tumors as well as other health
because of problems with their control       problems.
group—the people who did not use cell
phones or used them very infrequently.       Salivary gland tumors
Even if these people did not use cell
phones, many did use cordless phones in      Dr. Siegal Sadetzki and her colleagues at
their homes and offices.                     Tel Aviv University in Israel have found
                                             a link between salivary gland tumors and
Studies by Hardell have shown that use       cell phones.12 They reported that heavy
of a cordless phone increases the risk of    cell phone users were more likely to
certain types of tumors on the same side     have benign or malignant tumors of the
of the head almost as much as cell phone     salivary gland, compared to those who
use. This is because cordless phones,        did not use cell phones. These findings
unlike traditional land line phones, emit    became more worrisome when a July
radiofrequency radiation, and people         2009 Hebrew University-Hadassah
tend to have longer conversations on         School of Dental Medicine study found a
their cordless phones than they do on        sharp rise in the number of cases of
their cell phones.8, 9, 10                   cancer of the parotid salivary gland in
                                             recent years. From 1980 to 2002, there
In a July 2010 study, National Cancer        were an average of only 25 cases a year
Institute researchers tested whether brain   in Israel, but that nearly tripled to about
cancer rates increased in the years after    70 cases a year in the subsequent five
cell phone use increased.11 Data from        years.13
1992 to 2006 showed an increase in
frontal lobe cancer in 20 to 29 year old
women over this period, although the
same increase was not seen in men.

Migraines and dizziness                      Altered sperm count and quality

A 2009 study linked long-term cell           A 2007 study by researchers at the
phone use to migraines and dizziness         Cleveland Clinic showed that use of cell
(known as vertigo). In this study of         phones decreases sperm quality in
420,095 Danish adults, when comparing        men.17 They divided 361 men
long-term cell phone users with more         undergoing infertility evaluation into
recent cell phone users, the long-term       four groups according to the number of
users were 10-20% more likely to be          hours per day they spent talking on their
hospitalized for migraines and vertigo.14    cell phones. As the number of hours on
                                             the cell phone increased, the men’s
Sleep disturbance                            sperm count, sperm motility (number of
                                             “swimming” sperm), viability (ability of
A small 2007 study found that exposure       sperm to survive), and normal
to cell phone radiation before bed led to    morphology (normal shape of sperm)
less sleep and poorer quality of sleep.      each decreased. Other studies have had
People who were exposed to 884 MHz           similar findings. A Hungarian study
wireless signals for three hours before      following 231 men over a 13-month
bed took six more minutes to reach deep      period showed that for heavy users of
sleep and spent eight fewer minutes in       cell phones, sperm counts were, on
the deepest stage of sleep, in comparison    average, 30% lower for heavy users of
to when they were not exposed to the         cell phones compared to men who did
cell phone signals.15 These few minutes      not have or use a cell phone.18
per day could contribute to sleep
deprivation over several weeks and           Similarly, in a 2009 study, Dr. John
months.                                      Aitken from the University of Newcastle
                                             in Australia found that as levels of cell
Altered cell behavior                        phone radiation increase, the damage
                                             done to sperm also increases.19 Dr.
Exposure to cell phone radiation is now      Aitken therefore recommends that men
thought to alter the expression of certain   who would like to have children should
proteins in the human body. In a 2008        avoid carrying cell phones in their
Finnish study, females exposed to cell       pockets or anywhere below the waist.
phone radiation that mimicked a one-         This is a dramatic development because
hour phone call had significant changes      the level of radiation for a phone that is
in their levels of two different proteins    in a pocket while not being used is much
after they were exposed: “one protein        lower than the level of radiation during a
increased by 89%, the other decreased        phone conversation.
by 32%.”16 This was the first study
showing the molecular-level changes          Risks for Children
that take place in the human body, when
exposed to cell phone radiation.             A study published in 2008 in Physics in
                                             Medicine and Biology revealed that the
                                             brains of children under 8 absorb twice
                                             as much radiation from cell phones as
                                             adult brains.20 A 2010 study published

in Physics in Medicine and Biology            accounting for other factors that could
noted that, “in general and on average,       affect behavior, the children of these
children suffer a higher exposure of their    mothers were 80% more likely to have
brain regions than adults.” This is           behavioral problems than children whose
because children have proportionally          mothers rarely or didn’t use cell phones.
smaller heads and brains, yet receive the
same levels of cell phone radiation as        These results, based on a survey of
adults.21                                     Danish mothers whose children turned 7
                                              in 2005 and 2006, are troubling but also
None of the Interphone Project studies        somewhat difficult to interpret. Mothers
have looked at cell phone use begun in        using cell phones may be paying less
childhood or adolescence. Swedish             attention to their children, causing them
researcher Lennart Hardell, however, has      to “act out” in order to get attention.
begun tracking the effects of early cell      Research that is designed to provide
phone use. According to his research,         more details of cell phone usage and
people who begin using cell phones (and       other factors is needed to interpret the
cordless landline phones) before the age      relationship between a mother’s cell
of 20 are at an even higher risk of           phone use and her child’s behavior.
developing brain tumors than people
who begin using these wireless phones         Precautions You Can Take
as adults.22, 23 Wireless technologies are
proliferating daily, and different            Scientists recognize that most people are
countries have different limits on            not going to stop using cell phones.
radiation from wireless devices, which is     Since many studies suggest that there
why more and better designed research         may be risks, experts like Ronald
is urgently needed to determine safe          Herberman, Vini Khurana, and Lennart
levels of exposure. In the meantime, a        Hardell recommend that cell phone users
number of experts are recommending            take some precautions:
that pregnant women and children limit
their cell phone use.                         •   Limit the number of calls you make.
                                              •   Limit the length of your calls.
A study of more than 13,000 Danish            •   Use hands-free devices, put the cell
children published in Epidemiology                on “speaker phone,” or hold the
suggests that cell phone exposure could           phone away from your ear.
affect children’s behavior.24 The             •   When speaking on your cell phone,
children in the study who were                    alternate sides.
hyperactive or had emotional or               •   Limit your cell phone use in rural
behavioral problems, including trouble            areas or in any place where reception
getting along with other kids, were much          is poor. More radiation is emitted
more likely to have mothers who used              when you are farther from a cell
cell phones during pregnancy. The                 phone tower.
children’s problems, as reported by their     •   Shut off your phone or put it on
mothers, were even more pronounced for            “airplane mode” when possible.
children whose mothers used cell phones           Airplane mode means email,
both during pregnancy and during their            Internet, and phone can’t be used,
children’s first seven years of life. After       but you can listen to music or play

    games on the phone. This will            backpack, purse, or briefcase. If you
    reduce your exposure to radiation.       have to carry it in your pocket, it’s best
•   Text message instead of talking          to turn it off until you need it. And if you
    (never while driving!).                  use your cell phone as an alarm clock or
•   Check out how much radiation your        sleep near it, make sure it is at least a
    phone emits by looking at its SAR        few feet away.
    (specific absorption rate), which is a
    measure of the amount of radiation       In summary, although not enough time
    absorbed by your body. When              has passed for research to agree on the
    buying a new phone, try to select one    exact impact of cell phones on brain
    with a lower SAR. A list of cell         tumors and other health risks, the
    phones with the lowest SARs can be       evidence so far suggests that we should
    found here:                              be cautious. While hands free driving      laws are resulting in greater use of ear
    on/Get-a-Safer-Phone But                 pieces in cars, more and more people are
    remember, these SARs are based on        opting not to pay for land lines and are
    a six foot tall, 200 pound man with      relying exclusively on their cell phone.
    an 11 pound head, and the levels are     As a result, adults and children are
    higher for smaller people                holding cell phones to theirs ears for
•   Go over these guidelines with your       hours each day.
    children and limit their cell phone
    use.                                     Should we be concerned? Remember
                                             that most published studies evaluated
In some cities and states, taking these      relatively infrequent cell phone usage
precautions may soon be made easier. In      and that research is inadequate to draw
March, 2010 Maine legislators proposed       conclusions regarding safety. In the
a bill for placing warning labels on cell    Interphone studies, “regular” cell phone
phones. This would be like warning           usage was defined as at least one call per
labels on cigarettes, warning consumers      week for at least six months, which is a
about the increased risk of brain cancer     tiny fraction of typical usage today. The
from cell phone radiation. That effort       health impact of the long-term and
was unsuccessful, but in June 2010, San      frequent use of cell phones that is typical
Francisco voted to become the first city     today could be substantially worse. And,
in the U.S. where cell phone stores must     if there is a cancer risk, we won’t see the
list each cell phone’s SAR. This             effects of cell phone use on cancer rates
radiation level will be listed next to the   for another 10-20 years. That is why it is
cell phone’s features and price.             important that researchers who do not
                                             have financial ties to cell phone
Remember that cell phones emit               companies continue long-term studies
radiation whenever they are on—even          with more appropriate measures of high,
when they are not in use (although they      medium, and low cell phone usage and
emit even more during calls). So, avoid      include usage by children. In the
carrying the phone in your pocket or on      meantime, you can play it safe and limit
your belt. You can keep it handy but         your and your children’s cell phone use.
store it away from your body—in a


  “Researcher warns of brain cancer risk from cellphones. July 24, 2008. The New York Times. Complete warning from
Herberman can be read at:
  Hardell L, Carlberg M, Soderqvist F, Hansson Mild K, Morgan LL (2007). Long-term use of cellular
phones and brain tumours: increased risk associated with use for = 10 years. Occupational and
Environmental Medicine 64(9):626-632.
  Schuz J, Jacobsen R, Olsen JH, et al. (2006) Cellular telephone use and cancer risk: Update of a
nationwide Danish cohort. Journal of the National Cancer Institute 98: 1707-1713.
  Khurana VG, Teo C, Kundi M, Hardell L, Carlberg M (2009) Cell phones and brain tumors: A review
including the long-term epidemiologic data. Surgical Neurology 72(3): 205-214.
  Cardis E, Deltour I, Vrijheid M, Combalot E, Moissonnier M, Tardy H, et al (2010 May 17). Brain tumor
risk in relation to mobile phone use: results of the INTERPHONE international case-study. International
Journal of Epidemiology, 39(1): 675-694.
  Morgan LL, Kundi, M, & Carlberg M (2010 June). Re-evaluation of the Interphone Study: Application of
a Correction Factor. Retrieved from
  Lahkola A., et al. (2007). Mobile phone use and risk of glioma in 5 North European countries.
International Journal of Cancer. Volume 120; pages 1769-1775
  Hardell L, Carlberg M. (2009) Mobile phones, cordless phones and the risk of brain tumours.
International Journal of Oncology.35(1):5-17.
  Hardell L, Carlberg M, and Hansson Mild K (2006). Pooled analysis of two case-control studies on use of
cellular and cordless telephonesand the risk for malignant brain tumours diagnosed in 1997-2003.
International Archives of Occupational and Environmental Health 79: 630-639.
   Hardell L, Carlberg M, and Hansson Mild K (2006). Pooled analysis of two case-control studies on the
use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003.
International Journal of Oncology 28: 509-518, 2006.
   Inskip, PD, Hoover, RN, Devesa, SS (2010).Brain cancer incidence trends in relation to cellular
telephone use in the United States, Neuro-Oncology 12: 1147-1151.
   Sadetzki S, CHetrit A, Jarus-Hakak A, et al. (2008) Cellular phone use and risk of benign and malignant
parotid gland tumors-A nationwide case-control study. American Journal of Epidemiology 167: 457-467.
   Evan, Dan. Israeli study sees link between oral cancer, cell phones. July 17, 2009.
   Schuz J, Waldemar G, Olsen JH, & Johansen C. (2009 Feb. 5). Risks for Central Nervous System
Diseases among Mobile Phone Subscribers: A Danish Retrospective Cohort Study. PLoS ONE, 4(2): e4389
1-5. Retrieved from
   Arnetz BB et al (2007) The Effects of 884 MHz GSM Wireless Communication Signals on Self-reported
Symptom and Sleep (EEG)- An Experimental Provocation Study PIERS Online 3(7):1148-1150
   Karinen A, Heinavaar S, Nylund R, & Leszczynski D (2008 Feb. 11). Mobile phone radiation might alter
protein expression in human skin. BMC Genomics, 9(77). Retrieved from
   Agarwal A, Deepinder F, Sharma RK, Ranga G, & Li J (2007). Effect of cell phone usage on semen
analysis in men attending infertility clinic: an observational study. Retrieved from
   Fejes I, Zavaczki Z, Szollosi J, Koloszar S, Daru J, Kovacs L, et a; (2005 Sept-Oct). Is there a
relationship between cell phone use and semen quality? Arch Androl, 51(5): 385-393. Retrieved from
   De Iuliis GN, Newey RJ, King BV, Aitken RJ (2009) Mobile Phone Radiation Induces Reactive Oxygen
Species Production and DNA Damage in Human Spermatozoa In Vitro. PLoS One
4(7):e6446.doi:10.1371/journal.pone.0006446. (Accessed August 17,

   Wiart J, Hadjem A, Wong MF, Bloch I. (2008) Analysis of RF exposure in the head tissues of children
and adults. Physics in Medicine and Biology 53(13): 3681-3695 (15).
   Christ A, Gosselin MC, Christopoulou M, K’uhn S, & Kuster N. (2010 Jan.). Age dependent tissue-
specific exposure of cell phone users. Physics in Medicine and Biology, 55: 1767-1783. Retrieved from
   Hardell L, Carlberg M, Hansson Mild K. (2009) Epidemiological evidence for an association between
use of wireless phones an tumor diseases. Pathophysiology 16 (2-3): 113-122.
   Hardell L, Hansson Mild K, Carlberg M, Hallquist A. (2004) Cellular and cordless telephones and the
association with brain tumours in different age group. Archives of Environmental Health 59 (3): 132-137.
   Divan HA, Kheifets L, Obel C, Olsen J. (2008) Prenatal and Postnatal Exposure to Cell Phone Use and
Behavioral Problems in Children. Epidemiology 19(4): 523-529.