[ RadSafe ] Contribution from natural back ground radiation and medical radiation procedures

Tue Feb 14 22:36:15 CST 2006

Art Vandaly,
  Yet another important variable is the contribution from medical radiation procedures.The average effective dose to population from medical radiation procedures (mostly from diagnostic x-ray procedures) could be as high as one mSv annually in advanced countries. The absolute dose will be different for different workers. The integrated dose to these workers over the years will be of the order of or more than their occupational dose.
  I recollect when the erstwhile National Radiological Protection Board UK (J.A.Reissland, NRPB-R-79) reviewed the work of Mancuso et al on Hanford workers, the variability of the background radiation dose and medical radiation dose was highlighted. Mancuso et al in their analysis reported  doubling doses for cancer of the bone marrow as 0.8 rad;pancreas 7.4 rad; lung 6.1; all cancer 12.2 rads. Mancuso's paper was published in Health Physics (1977). Mancuso's paper drew extensive criticism.
  Regards

  K.S.Parthasarathy Ph.D
  (formerly, Secretary, Atomic Energy Regulatory Board)
  Raja Ramanna Fellow
  Department of Atomic Energy
  Room No 18
  Ground Floor, North Wing
  Vikram Sarabhai Bhavan
  Mumbai 400094
  E-mail ksparth at yahoo.co.uk
  91+22 25555327 (O)
  91+22 25486081 (O)
  91+22 27706048 (R)
  9869016206 (mobile)

mister radiation <allknowinghp at yahoo.com> wrote:
  Eric,

You have hit the nail squarely on the head. BAM!!! The background and it's variability is ignored in such epidemiological studies. For that reason they are not as useful as we like to tell people. The variation in dosimeter readings is also never considered. (This keeps employers from being sued and fined into oblivion when that dose comes in just under the limit.) Not to knock the radiationepidemiologists, it is difficult to find the right piece of hay in giant haystack.

The good news in all of this is that we will be able to continue debate Hormesis vs. LNT models for all eternity. 

Have a nice day,

Art Vandaly

goldinem at songs.sce.com wrote:

Somehow I've been roped into helping some high school students on a
radiation biology project. I suggested that they look into some major
epidemiological questions - one them being the risk from occupational
exposure. I have the BMJ Cardis paper on the 15 countries and had a
quick question. The cumulative exposure for the workers under
consideration averaged about 20 mSv. But for the sake of argument, most
of the workers are about 40 years old so they'd have an additional 100
or more mSv from natural background alone. I am far from an
epidemiologist but I assume that the basis for the risk coefficient
development was the determination of risks as a function of dose for the
dose distributions. But wouldn't the variability in natural background
be a huge confounder? I didn't see anywhere in the paper where natural
radiation exposure was even addressed.

Anyone have any clue whether that was considered or am I just missing
it? Thanks, Eric

Eric M. Goldin, CHP

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