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Cell
Phone Radiation Changes Brain Metabolism
Low-Level Effects Get a Boost
Microwave
News, February 22, 2011
A
well-regarded and influential team of researchers from the National
Institutes of Health (NIH) and the Brookhaven National Lab (BNL)
is on the brink of resolving a long-standing dispute with enormous
implications for public health. In a paper due out tomorrow, Nora
Volkow and coworkers are reporting that cell phone radiation can
affect the normal functioning of the human brain.
Whether these
short-term changes will lead to health consequences (and what they
might be) is far from clear though Volkow already has preliminary
indications of a long-term effect. Nor is the mechanism of interaction
yet known. But the new finding, if confirmed, would at the very
least force a rethink of the prevailing orthodoxy, which maintains
that low levels of RF and microwave radiation are too weak to have
any effect and can be disregarded.
"The study
is important because it documents that the human brain is sensitive
to the electromagnetic radiation that is emitted by cellphones,"
Volkow told the New York Times.
Using positron
emission tomography (PET), the NIH-BNL researchers have shown that
radiation from a 50-minute cell phone exposure can speed up glucose
metabolism, an established measure of brain activity. The finding
is highly statistically significant. What is particularly remarkable
about the new work is that those regions of the brain that were
most highly exposed to phone radiation had the largest increases
in metabolic activity. The NIH-BNL paper is published in the February
23rd issue of the Journal of the American Medical Association
(JAMA).
"This paper
is just dynamite," said David Carpenter, the director of the
Institute for Health and the Environment in Albany, NY. "It's
going to be very difficult to deny that RF radiation from a cell
phone does not alter nervous system activity." Carpenter, a
neurophysiologist, has been active in the electromagnetic research
community for over 30 years. "This work will turn the whole
issue around," he told Microwave News.
Ronald Herberman,
the former director of the University of Pittsburgh Cancer Institute,
called the NIH-BNL report "stunning."
The still dominant
view among health and safety committees is that if RF and microwave
radiation does not cause bulk heating, there will be no biological
effects. Yet, the changes in brain metabolism observed by the Volkow
group do not appear to have been caused by a temperature rise.
It is unlikely
that the changes seen in the brain could result from a thermal effect,
Volkow told Microwave News. Volkow is the director of the
National Institute on Drug Abuse (NIDA), one of the 21 institutes
that make up the NIH.
An editorial
that accompanies Volkow's paper echoes this conclusion. "Brain
areas that showed an increase in glucose metabolism were quite distant
from the [phone]. Thus, it is not likely that the effects were caused
by heating," wrote Henry Lai of the University of Washington,
Seattle, and Lennart Hardell of Sweden's Öreboro University
Hospital.
"It's time
to stop denying the existence of non-thermal effects," Hardell
said in an interview.
Lai and Hardell
pose what they call "an important question": whether glucose
metabolism in the brain might be "chronically increased from
the regular use of a wireless phone." Such potential health
effects need to be clarified, they stated.
In fact, Volkow
has some data suggesting that such chronic effects do occur: The
most active users of cell phones were found to have the largest
changes in glucose metabolism in those areas of the brain exposed
to the phone radiation. "We want to replicate these findings
before submitting them for publication," Volkow said. She added
that that she would continue to investigate whether the use of cell
phones has long-term consequences.
The new paper
does not address whether the use of a mobile phone may entail a
brain tumor risk. "These results provide no information as
to their relevance regarding potential carcinogenic effects (or
lack thereof) from chronic cell phone use," according to Volkow
and her colleagues.
An acute, short-term
effect alone would forever change the research landscape for electromagnetic
field effects. For decades, the microwave community has been awash
with reports that low-level radiation can lead to numerous neurological
effects, such as leakage through the blood-brain barrier, changes
in calcium in and around brain cells and DNA breaks in the brains
of exposed animals. But in each case skeptics have countered that
they could not repeat the experiments and therefore the original
work must have been flawed and should be repudiated. Volkow's new
study will no doubt face a similar barrage of criticism.
Cell Phone
Brain Scans
In the study,
47 healthy subjects, nearly evenly split between men and women,
were outfitted with a cell phone on each ear. Glucose metabolism
was measured using PET scans, a technique first developed at BNL
in the 1970s. Each participant was scanned twice, once when the
right-hand phone was turned on and once when both phones were off
(the phones were kept muted and the subjects were unaware when one
of the phones was active). The phone exposures lasted 50 minutes
and the PET scans were started five minutes after the phone was
turned off. They reflect the average brain activity over a 30-minute
period.
Although glucose
metabolism was not altered for the brain as a whole, there were
significant effects in those locations closest to the phone, the
right orbitofrontal cortex (see the arrowhead in the figure on the
left below) and parts of the temporal lobe. These areas of the brain
have been shown to have the highest RF radiation exposures when
using a mobile phone. As Volkow explains in the paper: The "regions
expected to have the greatest absorption of RF-EMFs from the cell
phone exposure were the ones that showed the larger increases in
glucose metabolism."
The scan on
the left is after a 50-minute cell phone exposure. Note the greater
metabolic activity in the right orbitofrontal cortex (marked by
the arrow). The scan on the right was made when the phone was
off. The regions in red are those with the highest rates of glucose
metabolism. Source: Journal of the American Medical
Association, 305, p.811, February 23, 2011
The observed
increases were "similar in magnitude" to those reported
after transcranial magnetic stimulation, a treatment for depression,
according to the NIH-BNL researchers. Their new study is one of
many they have carried out over the last decade. Last year, they
published a paper in NeuroImage showing reduced metabolic activity
in some regions of the brain during an MRI scan. Their emphasis
has most often been on the effects of drugs on the brain.
The NIH-BNL
team used two Samsung cell phones (model SCH-U310), transmitting
and receiving CDMA signals, with a maximum specific absorption rate
(SAR) of 0.901 W/Kg in the head. That is substantially lower than
the U.S. FCC's limit of 1.6 W/Kg for hand-held cell phones.
The paper does
not estimate the SARs expected in the regions showing the largest
changes in glucose metabolism. While it leaves the impression that
the phones were operating in receive-only mode and therefore
inducing lower SARs than when transmitting Dardo Tomasi,
a member of Volkow's team who has appointments at both NIH and BNL,
told Microwave News that the phones were operating "under
normal conditions, that is they were both receiving and transmitting
RF signals."
Volkow's new
study is bound to draw a great deal of attention, if only because
she is something of a science superstar. She has a high media profile,
turning up on numerous lists of the influential and powerful, including
Time magazine's "Top 100 People Who Shape Our World"
(2007) and Washingtonian magazine's "100 Most Powerful
Women" (2009). A decade ago, Volkow was named "Innovator
of the Year" by U.S. News and World Report. In 2003, when she
left a senior position at BNL to become the head of NIDA, Volkow
was the subject of a glowing profile in JAMA, which credited her
as having authored "dozens of pioneering brain imaging studies."
Today, she has published more than 440 peer-reviewed articles and
75 book chapters, according to her official NIH profile. Volkow
is the great-granddaughter of Leon Trotsky, the Russian revolutionary.
NIDA Director
Volkow Endorses Precaution
In an email
exchange with Microwave News, Volkow said that she recommends
taking precautionary measures. "Because we are uncertain of
whether there are or are not long term consequences," she stated,
"my recommendation is to use a wired earpiece, use the cell
phone in speaker phone mode or text message." Volkow is the
highest-ranking health official in the U.S. to call for caution
in the use of cell phones.
The closing
sentence of original version of the JAMA paper advised cell
phone users to keep the antenna away from the brain by using a wired
earpiece. This was edited out in the review/revision process.
[Read that last
sentence again. Don]
Additional
reading:
Your
Cell Phone May Be Hazardous to Your Health
The
Connection Between Cell Phones and Cancer
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