Re: Plutonium-238-containing cardiac pacemakers

["William CTR Kolb"<William.CTR.Kolb@faa.gov>]

Long-life nuclear powered pacemakers were manufactured by several companies from
the mid 1970s to the early 1980s. The batteries in these units contained up to 4
Ci (150 to 250 mg) of Plutonium-238 and had an expected life of more than 25 
years. Of the 1560 units that had been implanted as of 1986, about 900 were 
still in operation. Surface radiation levels were approximately 2 mrem/hr for 
gamma emissions and 1 mrem/hr for neutron emissions. Although the dose 
equivalent to tissue in contact with the implanted pacemaker ranged from 5 to 15
mrem/hr (90 rem/yr average), the whole body radiation dose rate was less than 
0.5 rem per year.  The estimated whole body dose to a spouse was about 7.5 
mrem/yr and ranged from 0.1 to 1.5 mrem/yr for other family members.  Patients 
implanted with these units are still tracked by the manufacturers in order to 
assure safe disposal of the nuclear material.

I wouldn't go so far as to say there were no qualms about having radioactive 
materials implanted. Remember this was a life saving operation and these units 
passed rigorous testing including crushing, cremation for 6 hours at 2400°F, 
simulated train, plane and automobile crashes, and gunshots. 

bill
william.ctr.kolb@faa.gov




______________________________ Reply Separator _________________________________
Subject: Plutonium-238-containing cardiac pacemakers 
Author:  <radsafe@romulus.ehs.uiuc.edu> at SMTPgate
Date:    5/25/99 7:18 AM


     
Hello Radsafers,
     
This is a request to anyone who might have any data on the number of 
Plutonium-238-containing cardiac pacemakers.  
> Are they still manufactured and used?  
Presumably, in the past, thousands of people were fitted with these devices 
(my old nuclear engineering text book has a very nice photo of one..). 
     
The reason I'm asking is that its related to the much publicized issue of 
transportation of mixed oxide (MOX) nuclear fuel containing small (~3 - 4%) 
amounts of Plutonium-239, derived from surplus US & Russian nuclear weapons 
stocks, and destined to be burned in nuclear powerplants (the "Swords to 
Ploughshares" solution to surplus plutonium disposition).
The plutonium isotope in these medical devices is about 290 times more 
radioactive than that which constitutes over 90% of weapons plutonium (it 
HAS TO be - otherwise its radioactive decay heating could not supply the 
required thermoelectric power for up to 35 years). Yet we have no qualms 
about letting people carrying plutonium in their chests travel on our 
subways, in our cars and airliners, and eat at our dinner tables. Even the 
patients' own personal radiation exposure from these implants is only about 
the same as the normal natural radiation background dose we all receive. 
     
Your information would be much appreciated.
     
Thank you.
     
> jaro
> 
frantaj@aecl.ca
     
     
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