Studies Show Wi-Fi Radio
Waves Are Not a Health
over the potential health effects of wireless signals has been around
since the early 1990s, with most of the attention focused on cell
phones. The FCC adopted limits for safe exposure to radio frequency
(RF) energy. Radio frequency radiation (RFR) is the propagation of
electromagnetic energy through space. It has two basic properties:
frequency and intensity. The effects of RFR are measured is by
absorption in human tissue. The unit for this measurement is called
the specific absorption rate (SAR) and is expressed in watts per
Some "studies" have
attempted to link the biological effects of Wi-Fi are typically
connected to studies on cell phone technology. Cell phones and Wi-Fi
operate on different levels of power intensity, but the standard for
SAR is the same. While some research has been conducted on the
biological effects of Wi-Fi on human tissue, more research has is
available on the effects of cell phone use.
FCC requires cell phone manufacturers to ensure that their phones
comply with these objective limits for safe exposure. Any cell phone at
or below these SAR levels (that is, any phone legally sold in the U.S.)
is a "safe" phone, as measured by these standards. The FCC limit for
public exposure from cellular telephones is an SAR level of 1.6 watts
per kilogram (1.6 W/kg), or between 0.6 watts and 3 watts. Robert
Bradley, director of consumer and clinical radiation protection at
Canada's federal health department indicates "If you look at the body
of science, we're confident that there is no demonstrable health effect
or effects from wireless technology,". A study was performed in 2005
at the Foundation for Research on Information Technologies in Society
in Zürich, Switzerland.
This study conclusively showed that by operating at a distance of 20 cm, Wi-Fi equipment is well below the U.S. standardsfor W/kg. Dr. John Moulder, a professor of radiation oncology at the
Medical College of Wisconsin, who has researched and reviewed the
biological effects of RFR, indicated that Wi-Fi posses no health risks.
Moulder and others point out that Wi-Fi equipment emits less intense
radiation than cell phones. Whereas most cell phones have a peak power
output of 2 Watts (some at 3), most Wi-Fi routers have a peak power
output of less than 100mW which is typical of indoor access points, and
400 or 500mW for outdoor units, but unlike cell phones and their base
stations, Wi-Fi devices do not communicate continuously. Dr. Kenneth
Foster, a professor of bioengineering at the University of
Pennsylvania, recently completed a study of Wi-Fi, taking over 350
measurements at 55 sites across four countries. According to his
research, not only does Wi-Fi equipment emit less radiation under load,
it does so in much smaller bursts. “When the networks were not being
used, the duty cycle was 0.01 percent or so. That means that it is
radiating power for 0.01 percent of the time.” While Wi-Fi and
microwaves use the same 2.4 GHz frequency, a microwave oven sends much more intense emissions than a Wi-Fi deviceor cell phone. However, “Studies have shown that environmental levels
of [radiofrequency] energy routinely encountered by the general public
are far below levels necessary to produce significant heating and
increased body temperature,” stated a 1999 FCC paper entitled
“Questions and Answers about Biological Effects and Potential Hazards
of Radiofrequency Electromagnetic Fields.”
Linda Erdreich, who has studied the biological effects of RFR for many
years, and is now a senior managing scientist at Exponent, a scientific
consulting firm, agrees with this assessment “We know that there is an
adverse effect [associated with RFR] and it starts with heating tissue,
but all of these things are well below the standard,” she says. Outside
the United States, similar conclusions have been made by related
entities in Canada, Europe and Australia. The Australian Radiation
Protection and Nuclear Safety Agency and the Canadian Spectrum
and Telecommunications use the same United States SAR value of 0.08
W/kg in an uncontrolled environment. Despite this internationally
compiled body of factual evidence regarding the health effects of
Wi-Fi, there remain a few concerned citizens who are not convinced.
Dr. Erdreich says “I think that the reason why there are differences
of opinions is because people are looking at single studies and not at
the whole picture.”
On a related note...
By Jeffrey Silva
Industry sighs in relief as court throws out brain-cancer suits
Story posted: August 24, 2007 - 1:02 pm EDT
Superior Court of the District of Columbia today threw out six
brain-cancer lawsuits against the mobile-phone industry, potentially
removing a legal cloud that could have cost wireless carriers and
manufacturers billions of dollars.
The decision to dismiss the suits was based on jurisdictional grounds,
with Judge Cheryl Long agreeing with the wireless industry and the
Federal Communications Commission that the complaints were pre-empted
by federal law. The six suits have bounced between Superior Court and
federal court since being filed several years ago. Today’s ruling was
the biggest for the wireless industry since a 2002 federal court
decision that tossed out an $800 million brain-cancer lawsuit against
wireless companies because of inadequate scientific evidence.
Long was unequivocal in her ruling.
“This is not a close question. Having found that multiple alternative
pre-emption doctrines are controlling, this court has no discretion to
allow the claims to proceed any further,” stated Long in the 69-page
Wi-Fi Won't Kill Your Family After All
09:15AM Wednesday Dec 05 2007
no solid scientific evidence that Wi-Fi is a health hazard, but that
hasn't stopped a parade of people from trying to stop Wi-Fi deployment.
In the U.S., teachers have sued schools to derail installs, while angel
guidance consultants have launched campaigns against Wi-Fi in their
In Canada, colleges have banned Wi-Fi, equating it to "second hand smoke."In the UK, some say they can feel the impact when they enter a room,
while others have started using Wi-Fi blocking paint (at $492 per can)
and sleep under silver plated mosquito netting.
The scare-mongering in the UK wasn't helped by a recent BBC report that
falsely claimed that Wi-Fi creates three times as much radiation as
mobile phone masts. The sensationalist program resulted in some London
politicians attempting to ban Wi-Fi use in schools. An official BBC
complaints ruling has subsequently found the program was misleading.
Goldacre, a doctor who runs the Bad Science website, stated that the
programme makers had made melodramatic, misleading television instead
of an informed documentary. "In 28 minutes of TV you could have given a
good summary of the research evidence so that people could make up
their own minds. But that would not get you as many viewers," he said.
A great quote from ITWeek columnist Les Hatton: "All I can say in reassurance is that this sort of mathematically dysfunctional scare-mongering drivel really makes me cross."