Cell phones interference

[andrew_mcewan@nrl.moh.govt.nz]

Peter
You wrote


Do you have any references on that? Our hospital rather uncritically decided
to ban cell phones here.  It seemed like somebody said they'd seen an
article.  It quickly became a case of "better safe than sorry!"  But cell
phones have become so common and there are so many signs that you see people
frequently using them.  There has been almost no effort, that I know of, to
enforce the ban and of course no incidents or that would have generated a
real effort.
Anyway if you have any references to offer, I'd be interested in getting
them.


_______


This is not an area I keep up on closely - I have read reports but do not have
anything at hand.  However, I understand that experiments have shown that some
medical devices, such as infusion pumps, ECG monitors, ultrasound scanners etc
may suffer interference if cellphones are used within two metres. Tests in
Middlemore Hospital, Auckland, found that about 20% of equipment tested was
susceptible.  Generally, problems were immediately evident and not
life-threatening.  I have heard a few anecdotal cases from Australia.  A person
who would be able to supply references is Ken Joyner, Motorola,
(c20471@email.mot.com) but he is overseas at present.


A  few  pacemakers  have been susceptible to interference if the handset is held
close  to  the chest.  These models reverted to a fixed pacing mode, but did not
fail  altogether.   In normal use, with the handset held close to the ear, there
are  no  problems.   (It  is perhaps worth noting that cellphones are not be the
only  source of interference, for example, two-way radios used by security staff
may pose greater problems.)


A  news  report  of 3 March this year indicated cell phone use on Tokyo sub-ways
was  being  banned  because  of  the  potential for effects on cardiac pacemaker
patients.   The  report stated "The government sponsored study showed pacemakers
could  temporarily  stop  operating  if  a  cell phone was in use within 22 cm".
(They   pack   the   passengers   in  fairly  tightly  in  Tokyo!)   The  city's
Transportation  Bureau  said "they had to institute the ban after receiving many
reports of passengers with pacemakers getting sick on trains".


Another small point.  I understand the magnet in the ear piece of some phones is
sufficiently strong to demagnetise credit cards.


Andrew McEwan


Andrew C McEwan PhD
National Radiation Laboratory
PO Box 25-099
Christchurch, New Zealand

Ph 64 3 366 5059
Fax 64 3 366 1156
Andrew_McEwan@nrl.moh.govt.nz


************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html