fluoro expos physicians? / summary

["Wenzl, Thurman" <tyw1@cdc.gov>]

I received 3 private responses in addition to 3 public ones (to my inquiry
last week). The most useful was a note that NCRP 122 quotes a survey of
Montreal cardio lab people wearing collar badges from '84-'88, with annual
means in the 2-3 rem range (Renaud 1992). This value is a bit lower than the
estimates of 2 posts: one suggested 1 rem/month, another 800 mr/qtr at the
collar. Since I'm interested in exposure to the brain, I'm focusing on
measurement results at the collar; I'm still hoping to see some data to
investigate possible trends. 

To add further context to my note, I'm trying to design a study to learn
whether there is excess risk of brain cancer associated with the use of
fluoro in interventional cardiology (and other specialties). Some of the
first evidence connecting leukemia and radiation came from a 1944 study by
March, comparing radiologists to other physicians.

BEIR V's summary on brain cancer (pg 311) mostly quotes studies of
therapeutically exposed populations, and says there is a brain cancer
association with poor knowledge of a dose-response relationship. 

Cardios and other physicians doing interventions w fluoro may have the
highest typical annual exposures at this time; by comparison, median annual
exposures among power workers seem to be around 200 mrem, with weapons
complex workers lower than that. 

Since my goal is well-designed research, I'm hoping to track down actual
data that would allow me to compare how collar exposures in the mid 70s and
mid 90s compare to those quoted above; a study of cardios would need to come
up with (a surrogate for) cumulative lifetime dose to the brain, and would
therefore like to understand any exposure trend (ideally, with data).

Some respondents pointed out that physician compliance with badging is not
good; I've also noticed that dosimetry recordkeeping may make my search
difficult, since I'm seeking clarity on badge location and physician
specialty.

The Amer Coll of Cardio does have a statement on this issue (on their web
pages), with some comments on dose per procedure. IF Renaud is typical, 400
procedures per year might be the median.

Thank you, everyone, for your responses so far. If any of you have access to
actual data at a medical center or large clinic, please consider sharing
summaries or at least discussing with me how much work would be involved in
summarizing the measurement results by badge location, specialty and decade.

Thurman B Wenzl   Sc.D.   tyw1@cdc.gov

Usual disclaimers apply; any opinions here should not be interpreted as
NIOSH policy. In fact, what I'm writing has not yet become a NIOSH study,
it's a draft that will be submitted into our process.
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