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No evidence that cell phones harm brains, bullets lag
spacecraft
 Q:
How can cell phones damage your brain? (Amy, Saltburn, England)
Wireless phones are two-way radios and emit radio waves —
radiation. [FDA]
A: So far, we don’t think cell phones do damage our
brains.
"The available scientific evidence does not show that any
health problems are associated with using wireless phones," says the US Food &
Drug Administration on their website (updated July 2003).
I’ve searched the literature for evidence found since then and
haven’t come up with much.
The closest thing to trouble that I’ve found — and it’s pretty
inconclusive — is an experiment done by Dariusz Leszczynski (head of the
Laboratory of Radiation Biology, Radiation and Nuclear Safety Authority in
Finland) and reported on Dec. 7, 2004 at the Cytoskeletal Organization II.
Leszczynski grew human endothelial cells (cells that form
liners in blood and lymph vessels) in a culture dish. He exposed the cells to
radiation at
GSM
cell-phone frequencies (900 or 1800 MHz). He tested the cell genes and
proteins after irradiating them. He found a protein (vimentin) that did change.
Some expressions of this protein had an unusually low molecular weight.
This change in the vimentin protein is a biological effect.
But, as Leszczynski points out, the change "does not automatically mean that
there will be a health effect."
Vimentin is an important building block used in the framework
of cells (cytoskeleton). It helps cells stick together to form tough structure.
If that building block changes, it could conceivably create flaws in the cell
structure. That, in turn, could cause problems with cell function.
So, Leszczynski plans to investigate more. He might find
trouble — a real health hazard. But, so far, he hasn’t. Just a change in a
protein.
This result just in (22 Dec. Reuter’s report): 12 European institutes conducted a 4-year study on human and
animal cells in the laboratory. They exposed the cells to somewhat higher
Specific Absorption Rates (0.3 to 2 watts per kilogram) than normal cell phone
radiation (0.5 to 1 w/kg).
Specific
Absorption Rates is a measure of heat in the tissues.
They found more breaks than normal in single and double strand
DNA. The cells couldn’t repair some of the damage so the DNA breaks could be
passed to the next generation. The researchers said the lab study did not prove
any health risks but plan more studies.
How about studies that might relate brain cancer to cell phone
use?
"I am not aware of any scientific population study that
demonstrates any connection between cell phone use and brain cancer," said Neal
Naff, the Chief of the Department of Neurology at Sinai Hospital of Baltimore.
"There are, however, several well conducted population studies that show cell
phone users are no more likely to develop brain cancers than people who do not
use cell phones."
To answer your question, maybe cell-phone radiation can
damage blood vessels in the brain or DNA. It’s conceivable but we have no
evidence that this actually happens. And, as Naff says:
"On a more practical level, all neurosurgeons I know use cell
phones extensively. If there were credible evidence that cell phones cause brain
cancer, I can assure you that neurosurgeons would not be using them."
Further Reading:
American Society for Cell Biology: Cell phone radiation shows biological effects
on cytoskeleton by John Fleischman
USA Today Tech: Phone makers ask for more research into DNA damage
FDA: Do
wireless phones pose a health hazard
FDA:
Wireless phones as radios
Networks and
Telecommunications Research: Definition of Specific Absorption Rates
 Q:
Which goes faster, bullets or rockets, and how much faster? (Ibrahim, Long
Beach, California)
A: Rockets go about 25 times faster than the fastest bullet.
If a bullet went as fast as a rocket, it would escape Earth’s gravity and keep
going — perhaps to Mars.
Indeed, Earth’s escape velocity (ignoring air friction) is
almost 10 times the fastest bullet — 25,000 mph (40320 km/h).
Spacecraft speed. In 2001, the spacecraft Odyssey left
Earth for Mars at about 67,100 mph (108000 km/h) and cruised thereafter at about
54,000 mph (87000 km/h).
Bullet speed. The fastest bullet
(probably the Winchester .223 Super Short Magnum) has a muzzle velocity of about
4000 feet per second or 2,700 mph (4400 km/h). Faster than a speeding bullet —
scarcely measures up.
Odyssey launches for Mars. April 7, 2001 [NASA/JPL/KSC]
Further Reading:
WonderQuest: How fast spacecraft cruise
Shooting Times Research Center: Winchester’s new .223 super short magnum by Dick
Metcalf
(Answered Dec. 31, 2004)
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