Cellular Phone Safety Questions Now Include Headsets | April, 2001 |
An Overview of Health Implications for Cellular Telephone Usage, Particularly Among Young Adults and Children | April, 2000 |
Cellular Phone
Safety Questions Now Include Headsets By: Matthew E. Brunnworth April, 2001 Introduction
In April, 2000, the British consumer
magazine, Which?, reported that hands-free kits for cellular phones do not
reduce the amount of radio frequency radiation being absorbed by the brain
as many people believe. They claimed the wire leading from the phone acted
like an antenna and increased the amount of radiation penetrating the head
by more than 300% when compared with placing a cellular phone against the
ear. Although their test methods were inconsistent with current regulatory
test procedures, newspapers worldwide published their findings. In July, 2000, and in response to
the Which? report, the British government commissioned an independent
laboratory, SARTest, to perform a series of SAR (Specific Absorption Rate)
tests that are consistent with current regulatory test procedures used
worldwide to measure and define the safety of cellular phones. The
validity of SAR test procedures as the criteria for determining cellular
phone safety is being debated globally. Using these procedures, SAR tests reported a reduction in the amount of radiation penetrating the head when using a headset of 90%. On the basis of this report, the British government reported that hands-free kits reduce phone radiation exposure and advised consumers to use them as safety devices. A similar report released by Australian scientists reported a reduction of 70%. Overall, these findings revealed
a 390% variance. Which? continued their
investigations and commissioned another series of tests by the same
laboratory that conducted their initial tests, ERA Technology LTD., in
October, 2000, using five different phones and two different hands-free
kits per phone. The test fixtures were presumably positioned in the way
that most people would use a cellular phone and a hands-free kit: the
phone positioned at or about waist level and the earpiece inserted in the
ear with the wire hanging freely. First, measurements were taken with the
phone handset next to the ear of a dummy head, and then taken again using
a hands-free kit. During testing, the phones were moved up and down to
vary the distance between the antenna mast and the earpiece. A follow up
report released in November reported their findings that hands-free kits
can reduce the amount of radiation penetrating the brain under a specific
condition, however they can increase it by up to 350% under most
conditions. They also reported why their findings were so different from
SARTests and those of the government.
The critical factor The radiation levels for all 10
hands-free kits varied between distances of 40 and 80cm. There were two
areas where the level of the signal at the ear was highest (from 40-47cm
and again between 58-75cm), and one area where the level was lower (from
47-58cm). In positions where the levels were higher, they were between
46 - 259% higher than the phones themselves. In positions where the
emissions were lower, the scale of the changes were between 8 - 97% for many
positions of a phone and hands-free kit worn in normal use, the tests
detected higher emissions from the kits than when the phones were held
against the head. The testing did reveal that while hands-free kits can
reduce the emission levels in one position, they also significantly
increase in all others tested.
Exploring SAR SAR tests are based upon a
calculated amount of energy that can safely be absorbed by the body,
measuring energy in watts per kilogram that one gram of body tissue
absorbs. It is calculated by measuring the maximum radio signal level
inside the head and applying this value to a formula to calculate a SAR. Tests are performed by inserting an electric-field test probe into a dummy head filled with a gel-like liquid that simulates the same electrical proprieties as brain tissue. In this case, it measures how much the brain heats up when a cellular phone is placed against the head and when a hands-free kit is used. Although in the process of being standardized as the method for rating radio frequency radiation from cellular phones, it is widely debated because it measures brain temperature increases after exposure for a brief amount of time and not actual radiation emissions. This is one of the primary reasons why AegisGuard™ Radiation Shields were tested using ASTM test procedures instead of SAR.
Some scientists
have concluded SAR levels are not the critical consideration because the
radio frequency can be a far more damaging element than the amount of
radiation absorbed. For example, a group of Spanish researchers released a
report in late 1999 stating this method of calculating cellular phone
emissions substantially underestimates their effects on human tissue.
SAR hands-free kit test
limitations
The most
significant difference is that with the SAR test system, the probe scans
the entire inside cavity of the dummy head and only provides a measurement
for the area where the highest radiation level appears. With the kits, the
highest emissions were at the ear; with the phones, it was at the jaw and
cheek. ERA tested the phone and the hands-free kit earpiece at the same
location, inside the head at ear level. Unlike ERA’s test, the SAR test
system does not provide a reading for radiation emissions at the ear
(close to the brain) for phones, only inside the dummy head.
Handle with care The controversial issue is
whether cellular phone radiation is dangerous to your health, and does the
use of a hands-free kit increase or decrease that risk. Most people will
attach the phone at the waist and connect a headset to it, causing the
phone to increase it’s output power, which is an important consideration.
This raises concern for unprotected body tissue at the waist level, such
as the liver and kidneys, which have excellent conductivity and absorb
radiation faster than the head due to a lack of surrounding bone. When a
hands-free kit is attached to a cellular phone, electrical currents are
conducted and induced on the wire, exposing internal organs and channeling
the radiation more effectively through the ear piece.
What scientists know Medical researcher Dr. Bruce
Hocking claims that cellular phones are likely to disturb nerve functions.
He has reported a marked difference in the responsiveness of nerves
behind, and just in front of, the ear after using of a cellular phone. Swedish medical investigators
conducted a two year study of patients with brain tumors.
They concluded that cellular phone users of analog phones (the kind
most commonly found in the U.S.) are at an increased risk of developing
brain tumors, which are most likely to appear on the side of the head
where users hold their phones. Cellular phones may present a danger even when they are not in use. Dr. Roger Coghill, a British biologist, found that cellular phones on standby mode lowered the white blood cells to 10% of normal activity after exposure to radio frequency radiation. A team of researchers in Spain claim the effects of cellular phone radiation could be 20% higher than previously thought. By studying more realistically shaped computer models of cells, they discovered electric fields are amplified across the cell membrane, a factor that had not been considered in other studies. It was also found that the angle of the cell in relation to the source of radiation is important, and that interactions between neighboring cells can significantly modify the electric field within each cell. Researchers have discovered that electromagnetic radiation can cause subtle, short-term biological effects, including changes in brain wave patterns during sleep. Although cancer studies have so far been inconclusive, organizations including the National Cancer Institute and World Health Organization are investigating the issue. Many experts caution it’s too early to give cellular phones a clean bill of health, and it is important to understand that cancers represent a small number of the heath effects attributed to cellular phone radiation.
Change of heart
FDA position
|
||
An Overview of Health Implications for Cellular Telephone
Usage, Particularly Among Young Adults and Children By: Katherine Krebs - Aegis Corporation April, 2000 Introduction The percentage of teenagers using cellular phones rose from 15% to 35% in 1999, and is projected to reach 70% by 2002. Without question, the cellular phone has become the accessory of choice among young adults, outselling PlayStations, TV's, and even personal computers. Teenagers regularly place calls from the mall to the classroom, use sophisticated phones to "surf the net" or check their e-mail, and chat with friends. However, technology does not evolve without consequences. A worldwide debate has ensued among scientists, regulatory agencies, and phone manufacturers over the health implications resulting from cellular phone usage. It should be noted that phone manufacturers and most regulatory agencies insist there are no health risks associated with the use of cellular phones. Executive Summary Though it has been difficult to find a conclusive link between cellular phone radiation and the effects among children, studies conducted have underscored the need for more research into the potential health risks, which point to greater biological damage for young children. This document was created to provide recent information about the potential health risks from cellular phone usage, including excerpts from published studies and comments from leading scientists in the field. To simplify the language in this report, the familiar phrase "cellular phone" is used, rather than a generic identifier such as "wireless communications device." The conclusions of this report are in no way intended to prove or disprove that wireless communication technology is safe or unsafe. Background Background studies have found:
Some scientists are conducting studies to determine if cellular phone usage has a greater impact on children than adults. Dr. Gerard Hyland, a physicist from the University of Warwick, is regarded as an expert in the field and among those who believe that cell phones could potentially be very dangerous for young children. Dr. Hyland is a specialist in the effect of low intensity radiation and said: "The problem is the electromagnetic emissions which come out in bursts from the body of a mobile phone. There is a certain frequency pattern in the emission that the brain happens to recognize. In children below the age of 12, the stability of the brain could be undermined and disrupted because their brain is in a more vulnerable state." Hyland warns that the radiation from cellular phones could also affect chemical activity in the brain. Said Hyland: "The blood brain barrier which keeps infections out of the brain could be made more permeable and that could increase the risk of infection." He warns that the radiation from cellular phones could also affect chemical activity in the brain. The Brain Barrier In the study, a team of 48 volunteers aged 18 to 49 were asked to complete a set of 12 tasks which tested a range of functions including reaction times, memory, accuracy and mental arithmetic. All volunteers were asked to carry out the same tasks during two sessions 24 hours apart. During both sessions, volunteers wore a phone mounted on a headset in the normal position with the antenna 4 centimeters (1.5 inches) from their heads. They were unable to tell whether or not the phones, controlled by a remote computer, were switched on or off. The Bristol study found decreased reaction times only in simple choice tests when users were exposed to old-style analogue phones, not digital handsets. Dr Alan Preece, who led the Bristol study, said: "This research basically confirms our findings. What we still don't know is what mechanism is causing these effects. There are three or four possible mechanisms which need evaluating before we can say what the long-term effects will be." In the next studies, scientists will consider whether radiation dilates the blood vessels feeding more oxygen to the brain, a mechanism linked to heating which is thought unlikely to cause long-term damage. What is the FDA's
Position? AegisGuard™ Radiation Shields: Your Partner for Precautionary Protection Cellular phones emit the same form of electromagnetic radiation produced by microwave ovens, and all microwave oven doors have embedded shielding material that deflects the radiation back into the cavity of the oven. Aegis engineers developed AegisGuard™ Phone Radiation Shields, a product family proven to deflect, rather than absorb, the radiation emitted from cellular phones and other wireless products (NOTE: This product was replaced by AegisGuard™ LS Radiation Shields in 2005). "This is a significant distinction because a shielding product using absorption materials loses its effectiveness as it becomes saturated, exposing the user to radiation," said an Aegis spokesperson in an April, 2000 press release. This distinction was confirmed by Dr. Neil Cherry, a biophysicist from Lincoln University and another expert in the field. During a radio interview in New Zealand on February 6, 2000, he said, "A (specific type of) fine metal mesh can provide significant shielding from UHF and microwave radiation. That is why microwave ovens have a reflective (deflective) metal grill over the glass door. If the holes are much smaller than the wavelength of the radiation, it is a good shield. The shield must work reflection (deflection) to avoid saturation." Conclusion What, then, can we do to limit our exposure to cellular phone radiation?
Consumer education programs need to be put in place. Educational materials should be developed and disseminated to educate the public about the potential health risks associated with cellular phone usage. These materials would inform people of the subtle influences of cellular phone use (e.g., thermal and radiation studies). They could illustrate how cellular technology emits radiation, include articles on the blood/brain barrier, and provide information about how to protect themselves. We hope that organizations and individuals worldwide take a particular interest in this issue. In addition, we hope it presents a call to action for further advocacy efforts surrounding this timely issue.
Copyright © 2024 Aegis Corporation- All Rights Reserved |