Are Cell
Phone Headsets Safe?
CNET Wireless
Journalist: David Carnoy
November 15, 2000
Until
recently, the underlying safety of cell phone headsets was not really a cause
for concern. The common wisdom was that if you were worried about cell phone
radiation and its potential health hazards, the best way to talk safely was to
get a headset. But that all changed a few months ago when Which, a British
consumer magazine, published a study that suggested that headsets or
hands-6.00 kits actually increased the level of radiation inside the head by
up to three times. Which further exacerbated the situation on November 2, when
it printed a follow-up study confirming its previous findings.
As you might
imagine, the study contains a lot of technical jargon that's not exactly
layman-friendly. But emerging from the technobabble are some key issues that
have fueled the controversy:
 |
ERA Technology, the independent laboratory
that conducted the testing for Which, did not initially measure
specific absorption rates (SAR). Instead, it set out to measure radio
frequency (RF) radiation emissions. Which says it's not anti-SAR, but
it questions the SAR measurement technique with regard to hands-6.00
kits. |
|
After
Which released its first study in April, the U.K. Department of Trade
and Industry (DTI) commissioned its own SAR test on hands-6.00 kits.
According to the government's report, the kits reduced radiation
exposure. |
|
In
response to the DTI report, Which conducted some SAR tests at the same
laboratory used by the DTI. According to Which, "We found no
positions where the kits gave higher readings than the phones. But we
also found that the shape of the SAR test rig made it impossible to get
the hands-6.00 kit wire into the position that gave the highest readings
in ERA's tests." |
So Are
They Safe?
Slightly baffled, I decided to call someone who'd actually tested headsets in
an independent lab to get his take on all this. I contacted Dr. Jacek J.
Wojcik, APREL Laboratories' CEO and president of the Spectrum Sciences
Institute. His company, based near Ottawa, Canada, recently measured SAR
levels for Plantronics' headsets and in the past has tested other headsets and
cell phones.
Decidedly in
the SAR camp, Wojcik says ERA Technology is flat-out wrong. "That lab
specializes in electromagnetics. There are electromagnetic fields everywhere,
but the human body does not necessarily absorb the energy."
Wojcik is
unmerciful in his criticism of ERA Technology's testing methods. "They
don't understand what they're doing," he says. "They're defending
mistakes they made in the first study and making more mistakes." He cites
a litany of problems--from the way in which the testing room was set up to the
amount of salt in the gel inside the phantom head that's meant to simulate the
same electrical properties as human brain tissue. "I don't know what
animal they picked up," he says, "but it wasn't human."
But let's get
back to the real issue: Are headsets safe? Wojcik explains that SAR is created
by radio frequency current. The current couples to the head via a magnetic
field that has a limited radius around the power source (the phone). Move the
power source away from your head, and your noggin won't be exposed to the
magnetic field. While the headset cord or wire may carry a signal, it's not
significant enough to create SAR at the level of the head. Contrary to Which's
suggestion that labs fail to lay out the headset cord so that it's fully
extended in a natural manner, Wojcik says his lab "lays out the cord in
such a way that we can scan the whole cord."
Back to
the Numbers
Let's say for the sake of argument that those in the SAR community, who
represent the majority view, are right, while Which's study is flawed. That
still leaves us with the SAR data. Just what numbers do manufacturers have for
headsets?
Well, Nokia,
Ericsson, and Motorola told me that all authorized headsets and hands-6.00
kits for their phones have been tested in labs and that all have maximum SAR
levels below the FCC's designated safe limit (1.6 W/kg). However, in keeping
with their SAR nondisclosure policy, the companies declined to give me the SAR
levels for those units.
Jabra, which
makes the popular Jabra EarSet, couldn't provide me with actual rating numbers
either. Instead, the company sent me a statement saying that "[Jabra]
maintains that use of the Jabra EarSet reduces the level of RF power entering
the head...by a factor of ten." That may be true, but it should be noted
that the "factor of ten" Jabra cites for its EarSet was derived from
internal test results, not an independent lab's.
Jabra's
statement goes on to say, "Other major cell phone and headset
manufacturers, such as Ericsson and Nokia, have gone on record to also confirm
our position. These companies state clearly that their tests, as well as those
by qualified outside test laboratories, confirm that the RF radiation at the
head is reduced through the use of a headset."
As far as I
know, Plantronics, which makes a wide assortment of headsets for cell phones
and cordless phones, is one of the few companies to publicly release its SAR
test results from an independent lab. APREL tested Plantronics' headsets and
found that they reduced SAR levels to practically zero in the head.
Wojcik says
that results of his tests of headsets from Plantronics and other major
manufacturers show that those particular models have maximum SAR levels that
are significantly lower than those of the phones with which they're tested.
Unfortunately, he can't reveal what companies make the other headsets he's
tested. Alas, the old disclosure policy rears its ugly head again.
Getting
Personal
"So based on your tests," I say to Wojcik, "if your wife were
to ask you whether headsets were safe, what would you tell her?"
"Nothing,"
he replies.
He cautions
that his labs' findings don't mean we can declare headsets to be universally
safe. It simply means that the models APREL has tested are well below the
FCC's designated safe level. "You know, scientists have done tests on
animals, and based on those tests, the FCC has set up very stringent limits,
which we use as benchmarks. Can we say headsets are absolutely safe based on
those numbers? No, because nothing's absolutely safe."
Wojcik
doesn't use a headset himself; he's not comfortable with the feel. But he says
he was happy to discover that the belt clip he wears for his StarTac does a
good job keeping the phone away from his body. Yes, that's another side of the
headset equation: where you carry your cell phone. For instance, if you have
the phone in your pocket while talking with an earpiece, your leg will absorb
the phone's RF emissions, but that's another column for another day.
However,
Wojcik discourages people from using the unproven cell phone radiation shields
that are becoming more and more prevalent in the marketplace. You don't want
to attach anything to the phone that might diminish its performance, he
explains, because that would actually cause the phone to work harder to
receive a signal and potentially raise SAR levels, nor do you want a belt clip
with any metal parts that might enhance the energy emitted from the phone.
But back to
Wojcik's wife: Just what would he tell her about headsets?
"I think
the psychological impact is important," he says. "I mean, people get
headaches just from thinking they're being exposed to radiation. So I'd tell
her that if you want to wear something that makes you feel safe, by all means
do it."
The moral of
this story, I suppose, is that perception is crucial in this whole debate of
radiation levels. In many ways, the lack of public SAR information about
headsets (and by public, I mean information printed on the outside packaging)
was what made headset manufacturers vulnerable to these studies, which may or
may not be flawed.
